HomeMy WebLinkAboutFlood Control Project for the Mamaroneck and Sheldrake Rivers Basin Final Environmental Statement 1/1/1979 FINAL
ENVIRONMENTAL STATEMENT
FLOOD CONTROL PROJECT
FOR MAMARONECK AND SHELDRAKE RIVERS BASIN
(Vi and Town of-Mamaroneck, N.Y. )
FOR BYRAM RIVER BASIN
(Greenwich, Conn. and Port Chester, N.Y. )
OFFICE OF THE CHIEF OF ENGINEERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C. 20314
JANUARY 1979
ADDENDUM
Modification of the Recommended Flood
Control Plan for the Mamaroneck and
Sheldrake Rivers Basin, Town and Village
of Mamaroneck, New York
General. Based upon a recent review completed by the Board of Engineers for
Rivers and Harbors, the Town of Mamaroneck project area along the upper Sheldrake
River, is no longer to be included as part of the recommended plan.
The Scope of the Board Review. The scope of the Board review included the
engineering, economic, social, environmental, and policy aspects involved in the
reporting officer's plan. The need for and feasibility of the proposed improve-
ments were examined.
The Board noted that Engineering Regulation 1165-2-21, "Flood Damage Reduction
Measures in Urban Areas." was published as a "final rule" in the Federal Register
on 8 May 1978. That regulation specified criteria to distinguish between improve-
ments to be accomplished by the U.S. Army Corps of Engineers under its flood
control authorities and storm sewer systems to be accomplished by local interests.
One of the criteria for addressing water damage problems under the flood control
authorities is that the 10-year flood event must equal or exceed a discharge of
800 cfs. The Sheldrake River in the Town of Mamaroneck project area has a 10-year
flood discharge of about 570 cfs.
Board Findings and Recommendations. The Board concluded that the proposed project
for the Town of Mamaroneck is an economically and a technically feasible solution
to the flood problem. However, in accordance with existing Corps of Engineers
policy, the project can not be accomplished under the Corps ' flood control autho-
rity and should be deleted from the overall recommended plan. The considered Town
of Mamaroneck project should be addressed as part of an adequate storm sewer
system which is the responsibility of the local interests .
Environmental, Social, and Economic Effects of Project Implementation. The environ-
mental and social effects that may be anticipated, should the proposed plans be
constructed, are those reported in this Revised Environmental Impact Statement.
However, as a result of the recommended deletion of the Town of Mamaroneck portion
of the project, no construction related impacts would occur in this area. The
existing conditions within this flood-prone area would be expected to remain the
same unless the local interests develop a non-federally funded flood alleviation
plan of their own. In addition, the economic evaluation appearing in the text of
this report is essentially the same, with the exception that the total Federal
share for this project would now be reduced correspondingly (refer to the the
attached economic evaluation of the recommended plans, and to Table 1, page 9, for
comparison) .
ECONOMIC EVALUATION OF THE CONSIDERED
PLANS OF PROTECTION (DECEMBER 1976 PRICE LEVELS)
TOTAL BENEFIT
FEDERAL NON-FEDERAL TOTAL ANNUAL ANNUAL COST
FIRST COST FIRST COST FIRST COST COST BENEFITS RATIO
I. CONSIDERED PLAN FOR
MAMARONECK & SUELDRAKE
RIVERS - PLAN A (NED)
PLAN
Mamaroneck & Sheldrake
Rivers - Village of
Mamaroneck 27,888,000 4,781,000 32,669,000 2,117,400 2,632,800 1.2
II. CONSIDERED PLAN FOR
BYRAM RIVER -
NED PLAN 3,532,000 943,000 4,475,000 309,000 448,700 1.5
SUMMARY
FLOOD CONTROL PROJECT
FOR MAMARONECK AND SHELDRAKE
RIVERS BASIN
AND
BYRAM RIVER BASIN
( ) Draft Environmental Statement (x) Final Environmental
Statement.
Responsible Office: U.S . Army Engineer District, New York
26 Federal Plaza
New York, New York 10007
Tel. (212) 264-4662
1. Name of Action: ( ) Administrative (X) Legislative
2a. Description of Action: (Village of Mamaroneck-Mamaroneck
River) . The plan of protection involves a combination of channel
modification, retaining walls and bridge replacement. The exist-
ing channel of the Mamaroneck River would be widened and deepened
a distance of approximately 10, 000 feet. The modified channel
bottom along the Mamaroneck River would vary in width from 60
feet at lower limit of the plan to 45 feet in width at the up-
stream limit of the channel works. The channel modification
would include the relocation of the confluence with the Sheldrake River
to eliminate the two sharp bends in the existing alignment, and
construction of a number of discontinuous retaining walls . The
plan additionally involves the replacement of five bridges . In-
terior drainage is provided by a system of ditches and outlet
drains through the line of protection, and several areas along
the streams would be filled and graded. This plan is designed to
protect against a flood with a . 5 percent exceedence frequency
(200 year flood) along the Mamaroneck River downstream of the New
England Thruway, and against a flood with a 1 percent exceedence frequency
(100 year flood) along the Mamaroneck River upstream of the Thruway to Winfield
Avenue.
2b. (Village of Mamaroneck-Sheldrake River) . The Sheldrake River
would be diverted into a tunnel at Fenimore Road leading to the
West Basin of Mamaroneck Harbor. This tunnel diversion would con-
sist of three segments. For 1, 600 feet from the Sheldrake River
to Stanley Avenue the tunnel consists of a 15 ' x 15' box culvert;
from Stanley Avenue for 1, 450 feet to just north of Boston Post
Road, the diversion consists of a 15. 5 foot diameter tunnel and
thence the tunnel consists of a 15 ' x 15 ' box culvert to just
south of Boston Post Road where the tunnel leads to an open chan-
nel and stilling basin at the West Basin of Mamaroneck Harbor. From the diver-
sion inlet at Fenimore Road upstream to Rockland Road the existing channel of
the Sheldrake River would be modified into a semi-trapezoidal channel , with a
retaining wall along the right bank. The tunnel diversion and modified charnel
upstream of the inlet are designed to contain the Standard Project Flood (.1
percent exceedence frequency [1,000 year flood] ) along the Sheldrake River.
This diversion system would divert the total flow of the Sheldrake River
upstream of Fenimore Road into the tunnel.
2c. (Town of Mamaroneck - Sheldrake River) . The plan of protection consists
of a twelve foot wide concrete/rock cut rectangular channel from a point lo-
cated approximately 250 feet upstream of Rockland Avenue, at Brookside Place,
and would then continue downstream for about 1,800 feet. The plan also
includes a transition stilling basin approximately 300 feet downstream of
Briarcliff Road, and a ?2 foot long drop structure and tie back levees at the
upstream limit. The Forest Avenue, Landsdowne Drive, Hickory Grove Drive and
three driveway bridges would be replaced, and low-lying areas along the stream
would be filled and graded. This pian is designed to protect against a flood
with a 1 percent exceedence frequency (100 year flood).
2d. (Port Chester and Greenwich-Byram) . The considered plan along the Byram
River involves cannel excavation, floodwalls and levees. The channel of the
Byram River would be dredged for approximately 700 feet downstream of the
southern U.S. 1 Bridge. The new channel would be 70 feet wide and the riverbed
beneath the two U.S. 1 Bridges would also be lowered. Channel rodifications
would occur upstrear of the two U.S. 1 Bridges, a distance of 2,000 feet with
channel widths varying from 40 to 50 feet. Approximately 1,?50 feet of flood-
walls and ?,400 feet of levees are proposed along the banks at various loca-
tions. in addition, about u00 feet of existing levees would be raised approxi-
mately 2 feet upstream of Rex Street. A concrete sill with a top elevation of
6.0 feet Mean Sea Level is proposed for the mouth of Pemberwick Lake to main-
tain its elevation during times of low flow. Ponding areas, pumping stations,
storm drainage interceptors and other associated interior drainage facilities
would be provided behind the levees and walls to carry surface runoff from the
area protected. This plan is designed to protect against a flood with a 1
percent exceedence frequency (100 year flood).
2e. The evaluation of the discharge of dredged or fill material into waters of
the United States, including consideration of the Section 404(b) (1) Guidelines,
has not been completed, and therefore, the Environmental Impact Statement on the
project does not include the information required by Section 404(r) , Public Law
92-500, as amended.
3a. Environmental Impacts : Impacts beneficial to residents and public services
would result from the implementation of the proposed projects . The proposed flood
protection plans would produce monetary benefits by reducing flood damage and
business losses and enhancing land values. The dangers to life and health asso-
ciated with floods and disruptions which occur during flood situations also would
be minimized.
3b. Adverse Environmental Impacts: Implementation of the proposed structural
plans would be expected to cause certain temporary and permanent effects . Air qua-
lity, noise levels and the appearance of the area would be adversely impacted by
the construction activities. The movement of trucks with construction materials ,
through streets , and equipment operation would generate noise and contribute to
air pollution by windblown dirt and gas emissions . There would be some interfer-
ence with normal traffic conditions. However, all of these impacts would be tem-
porary, lasting only during construction. Channel excavations to widen and deepen
the rivers would
create temporary turbidity which could adversely affect water quality downstream.
Impacts of a more permanent nature include the removal of streambank vegetation,
some loss of fish and wildlife habitat and the aesthetic effect of the modified
appearance of the streams and the land due to the presences of structural works.
4 . Alternatives : Other plans considered include non-structural
methods such as evacuation of the floodplain, flood proofing and
land use regulations. Structural solutions included detention
reservoirs, diversion tunnels, floodwalls and levees without
channel modifications, alternate alignments of levees and flood-
walls and channel modifications plans along with a "no action"
alternative.
5a. Comments Received: (District Review)
FEDERAL AGENCIES
Department of Agriculture
Forest Service
Soil Conservation Service
Department of Commerce
National Marine Fisheries Service
National Oceanic and Atmospheric Administration
Department of Health, Education and Welfare
Region II Administrator
Department of the Interior
Bureau of Outdoor Recreation
Bureau of Sport Fisheries and Wildlife
Regional Director, National Park Service
Department of Transportation
Federal Highway Administration
Coast Guard
Environmental Protection Agency
Regional Administrator, Region II
STATE Z'_CENCIES - NEW YORK
Department of Environmental Conservation
STATE AGENCIES - CONNECTICUT
Department of Environmental Protection
LOCAL AGENCIES
Inland Wetlands and Water Courses Agency - Town of Greenwich,
Conn.
5b. Comments Received: (Departmental Review)
Department of Agriculture
Department of Health, Education and Welfare
Department of Housing and Urban Development
Department of the Interior
Environmental Protection Agency
New York State, Department of Environmental Conservation
Connecticut, Department of Environmental Protection
6. Draft Statement to CEQ 14 January 1977.
Revised Draft to EPA 23 August 1978.
Final Statement to EPA -
FINAL ENVIRONMENTAL STATEMENT
FOR FLOOD CONTROL PROJECT
AT MAMARONECK AND SHELDRAKE RIVERS BASIN
AND
THE BYRAM RIVER BASIN
TABLE OF CONTENTS
Item Page
1. PROJECT DESCRIPTION
1. 01 Introduction 1
1 . 02 Authority 1
1. 03 Problem Identification 1
1. 04 Planning Objectives 1
1 . 07 Description of Mamaroneck-Sheldrake
River Basin Recommended Plan 3
1 . 12 Cost of Recommended Plan (Plan A) 5
1. 13 Benefits 5
1. 14 Economic Evaluation 5
1. 15 Description of the Recommended Plan for
Byram River 5
1. 16 Costs of the Recommended Byram River Plan 6
1 . 17 Benefits 6
1. 18 Economic Evaluation 6
1 . 19 Local Cooperation 6-7
2. ENVIRONMENTAL SETTING WITHOUT THE PROJECT
LOCATION
2. 01 Mamaroneck Sheldrake Rivers Basin 11
2. 05 Byram River Basin 12
POPULATION
2. 06 Mamaroneck-Sheldrake Study Area 12
2. 07 Byram River Study Area 13
MANUFACTURING AND EMPLOYMENT
2 . 08 Mamaroneck Town and Village 14
2. 09 Byram Study Area 16
CLIMATE
2. 10 Mamaroneck, Sheldrake and Byram River Basins 16
PRECIPITATION
2. 12 Mamaroneck, Sheldrake and Byram River Basins 16
Item page
STREAM FLOW AND RUNOFF
2. 13 General 18
STORMS
2. 14 Mamaroneck, Sheldrake and Byram Rivers Basins 18
STORM DAMAGES
2 . 19 General 20
2. 20 Mamaroneck and Sheldrake Rivers Basin 21
2. 23 Byram River Basin 22
GEOLOGY
2. 24 Mamaroneck and Sheldrake Rivers 22
2. 25 Byram River 23
SOIL EXPLORATIONS
2. 26 Mamaroneck and Sheldrake Rivers Basin 23
2. 27 Byram River Basin 23
WATER SUPPLY
2 . 28 Mamaroneck and Sheldrake Rivers Basin 23
2. 29 Byram River Basin 24
GROUNDWATER
2. 30 Mamaroneck, Sheldrake and Byram Rivers Basins 24
WATER QUALITY
2. 31 Mamaroneck and Sheldrake Rivers Basin 24
2. 34 Byram River Basin 26
FISH AND WILDLIFE OF THE 1AMARONECK AND SHELDRAKE
STUDY AREA
2. 36a Wildlife Habitat 29 _
2. 37 Vegetation 29
2. 38 Wildlife 29
2 . 39 Birds 29
2. 40 Fisheries Resources 30
Item page
FISH AND WILDLIFE OF BYRAM RIVER STUDY AREA
2. 42 Wildlife Habitat 30
2. 43 Vegetation 31
2. 44 Wildlife 31
2. 45 Birds 31
2. 46 Fisheries Resources 31
RECREATION FACILITIES
2. 47 General 32
2. 48 Mamaroneck-Sheldrake Study Area 32
2. 51 Byram River Study Area 33
TRANSPORTATION
2. 53 Mamaroneck, Sheldrake and Byram Rivers Basins 33
AIR QUALITY AND NOISE
2. 55 Mamaroneck, Sheldrake and Byram Rivers Study Area 34
AESTHETICS
2 . 56 Mamaroneck Sheldrake Rivers Basin 34
2. 57 Byram River Basin 34
ARCHEOLOGICAL AND CULTURAL RESOURCES
2 . 58 Mamaroneck, Sheldrake and Byram River Basins 35
3 . RELATIONSHIP OF THE PROPOSED ACTION TO LAND USE PLANS
3 . 01 General 36
EXISTING LAND USE AND ZONING
3 . 02 Mamaroneck-Sheldrake Rivers Basin 36
3 . 03 Byram River Basin 36
FUTURE DEVELOPMENT AND THE FLOOD PLAIN
3 . 04 General 37
3. 07 Land Acquisitions and Spoil Disposal 38
Item page
4 . ENVIRONMENTAL IMPACT OF THE PROPOSED ACTION
4. 01 General 39
4 . 04 Aesthetics 39
4 . 05 Geology and Soils 40
4 . 06 Sedimentation 40
4 . 07 Water Resources 40
4 . 09 Water Quality 41
4. 10 Maintenance 41
4 . 11 Air Quality 41
4 . 12 Noise 41
SOCIAL EFFECT-MAMARONECK-SHELDRAKE
AND BYRAM STUDY AREAS
4 . 13 Community Cohesion 42
4 . 14 Employment Effects 42
4 . 15 Taxes and Property Values 42
4 . 16 Displacement of People, Businesses and Farms 42
4 . 17 Community and Regional Growth 42
4. 18 Institutional Impacts 42
VEGETATION, FISH AND WILDLIFE RESOURCES
4 . 19 General 42
4 . 22 Mamaroneck-Sheldrake Rivers Basin 44
4 . 23 Byram River Basin 44
4. 24 Impacts Associated with the Fenimore Road Diversion
Tunnel 45
4 . 27 Dredging Impacts 46
RECREATION FACILITIES
4 . 28 Mamaroneck and Sheldrake Rivers Basin 47
4 . 29 Byram River Basin 48
TRANSPORTATION
4 . 30 Mamaroneck and Sheldrake Rivers Basin 48
4 . 31 Bridge Work_ 48
4 . 32 Fenimore Road Diversion Tunnel 48
4 . 33 Mamaroneck Station Parking Area 49
4 . 34 Byram River Basin 49
ARCHEOLOGICAL AND CULTURAL RESOURCES
4. 35 General 49
4. 36 Mamaroneck and Sheldrake River 50
4 . 37 Byram River 50
Item Page
MITIGATION MEASURES
5. ANY PROBABLY ADVERSE EFFECTS WHICH CANNOT BE
AVOIDED
5 . 01 General 52
6. ALTERNATIVES TO THE PROPOSED ACTION
6. 01 General 53
6. 02 Formulation Criteria 53
6. 03 Technical Criteria 53
6. 04 Economic Criteria 53
6 . 06 Environmental Criteria 54
6 . 07 Social and other Considerations 55
POSSIBLE SOLUTIONS
6 . 08 General 55
6. 09 Non-Structural Measures 55
6. 10 Floods Proofing 56
6. 11 No Action-Maintain Base Condition 57
6. 12 Other Measures 57
6. 13 Reservoirs 57
6. 14 Diversions 57
6 . 15 Mamaroneck River Diversion 58
6 . 16 Local Protection Measures 58
6 . 17 Structural Measures, Byram River 58
6. 18 Diversions and Reservoirs 59
6. 19 Local Protection Measures 59
6. 20 Non-Structural and Structural Combinations 59
DEVELOPMENT OF INTERMEDIATE PLANS
6 . 21 General 60
6. 22 National Economic Development (NED) and
Environmental Quality (EQ) Plans 60
ALTERNATIVES CONSIDERED FOR DETAILED
ANALYSIS
6 . 23 General 61
6. 24 Village of Mamaroneck-Upper Mamaroneck River-
Non-Structural Plan 61
6. 25 Town of Mamaroneck-Sheldrake River-Non-Structural
Plan 64
6. 26 Non-structural Plan 64
6 . 27 Contributions to National Objectives 64
6. 28 Mamaroneck and Sheldrake Rivers , National
Economic Development (NED) Plan 64
Item page
6 . 29 Environmental Quality (EQ) Plan 65
6. 30 Identified Plans 66
6 . 31 Comparison of Identified Plans 66
6. 35 The Selected Plan 68
6. 36 Byram River, National Economic Development (NED)
Plan 68
6 .37 Environmental Quality (EQ) Plan 68
6 . 38 Comparison of Identified Plans 69
6. 42 The Selected Plan 70
7. THE RELATIONSHIP BETWEEN LOCAL SHORT-TERM USES OF
MAN' S ENVIRONMENT AND THE MAINTENANCE AND EN-
HANCEMENT OF LONG-TERM PRODUCTIVITY .
7. 01 General 71
8 . IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RE-
SOURCES WHICH WOULD BE INVOLVED IN THE PROPOSED
ACTION SHOULD IT BE IMPLEMENTED
8. 01 General 72
9. COORDINATION
9 . 01 General 73
9. 02 Public Participation 73
9. 03 Governmental Agencies 73
APPE14DICES
Appendix A Letters Received by the Corps of Engineers
as a Result of Coordination of the DEIS
Appendix B Letters Received by the Chief of Engineers as a Result of
Coordination of the RDE IS
Appendix C Biological Inventory of Mamaroneck, Sheldrake and Byram
Rivers Basins
Appendix D State Water Quality Classifications
Appendix E Letters of Coordination, Cultural Resources Survey
Appendix F USF & W Service and Corps Letter
FIGURES
1. Basin Map
2. Location Map Village and Town of Mamaroneck, N.Y.
3. Considered Plan, Plan A, Village of Mamaroneck Study Area
Item Page
4 . Considered Plan, Plan A, Sheldrake River
Town of Mamaroneck Study Area
5 . Byram River Flood Control Project
6. Considered Plan Greenwich, Connecticut
Port Chester, New York
TABLES
1. Economic Evaluation of the Considered Plans of
Protection (December 1976 Price Level) 9
2 . Land Acquisition Requirements for the Considered
Plans of Protection (In Acres) 10
3. Total Population, Mamaroneck Village, Mamaroneck
Town and Selected Areas 13
4. Population, Port Chester, New York and Greenwich,
Connecticut 14
5. Labor Force-Employment and Unemployment 15
6. Labor Force, Employment and Unemployment
Greenwich, Conn. , Fairfield County, Conn.
and Port Chester, New York 17
7. Stream Discharge Data 19
8. Sediment Analysis of Bottom Grab Samples 27
8a. Standard Elutriate Test 27a
9. Water Resources Data 28
10. Applicability of Non-Structural Methods 56
11. Summary of Physical Features of the Structural
Intermediate Plans of Protection for
Mamaroneck and Sheldrake Rivers at the
Village and Town of Mamaroneck, New York 62
12. Summary of Physical Features of the Intermediate
Plans for Flood Control of Byram River in the
Tow of Greenwich, Connecticut and the Village
of Port Chester, New York 63
13 . Summary Comparison of Identified Plans Mamaroneck
and Sheldrake Rivers at the Village and Town of
Mamaroneck, New York 64a
14 . Summary Comparison of Identified Plans Byram River
at Greenwich, Conn. and Port Chester, N.Y . 64b
REVISED DRAFT
ENVIRONMENTAL STATEMENT
FOR FLOOD CONTROL MAMARONECK
AND SHELDRAKE RIVER BASINS
AND
THE BYRAM RIVER BASIN
1 . PROJECT DESCRIPTION
1. 01. Introduction. The purpose of this statement is to assess
the environmental, economic and social effects of the recommended
flood control plans proposed for the 1) Mamaroneck and Sheldrake
Rivers at the Village and Town of Mamaroneck, Westchester County,
New York and for the 2) Byram River at the Village of Port Chester,
Westchester County, New York and the Town of Greenwich, Fairfield
County, Connecticut.
1 . 02 . Authority. A Feasibility Report was prepared in December
1976 by the New York District Corps of Engineers as part of the
basin-wide flood control studies program for streams in Westchester
County, New York and Fairfield County, Connecticut. The Feasi-
bility Report is submitted in compliance with resolutions of the
United States Senate Committee on Public Works adopted 14 Septem-
ber 1955 and 14 November 1955, and with a resolution of the United
States House of Representatives Committee on Public Works adopted
13 June 1956. All of these resolutions were adopted as a result
of the damaging hurricane floods of August 1955 and October 1955 .
The final environmental statement has been developed in accordance
with the requirements of the National Environmental Policy Act of
1969 and applicable Corps of Engineers Regulations .
1. 03. Problem Identification. The citizens of the Mamaroneck and
Sheldrake Rivers basin and the Byram River watershed have each ex-
perienced recent flood related economic losses and human misery and
have long recognized the potential for flood damage and threats to
human life which may occur in the future (refer to Paragraphs 2 . 19
-2. 23) . Protection from these potential losses have been sought by
local interests in both watersheds for many years. The existing
flood hazard and associated flood damages constitute by far the most
serious water resources problem in each of the subject basins . The
basic objective of the plan formulation process is to develop plans
which will provide the best use or combination of uses of water and
related land resources to meet the flood protection need of each
watershed.
1 . 04 . Planning Objectives. The lists in the following paragraphs
comprise the final array of planning objectives derived by analyz-
ing the water and related land resources problems and needs of the
Mamaroneck and Sheldrake Rivers and Byram River basins , respec-
tively, in relation to the most probable alternative future, and re-
flects several iterations of the planning process. Thus, the plan-
ning objectives listed below provide a basis for plan evaluation.
These objectives primarily address the serious flood control prob-
1
lems and other associated needs, such as the preservation of open
space, and fish and wildlife at the flood problem areas, within
each of the subject basins . Comprehensive recreational enhancement
was not considered in light of the extensive number and variety of
recreational facilities which exist in or near the Mamaroneck and
Sheldrake Rivers and Byram River basins, and indications by local
interests that there is no desire to incorporate recreational fea-
tures into plans of flood protection. The development of water
supply sources within the subject basins was also not considered as
a planning objective. A cultural resources reconnaissance study has indicated
that no resources in the study areas are eligible for nomination into the National
Register of Historic Places, and that no other significant archeological or cult-
ural resources are known to exist. Additionally, the needs of the watersheds with
regard to wastewater treatment and water quality problems are considered under
programs of other Federal, State and local governmental agencies and are not
treated in this study, except for the prevention of further degradation of water
quality through stream bank erosion at the flood problem areas. Specific objec-
tives developed for the Mamaroneck and Sheldrake Rivers and Byram River basins
are presented in the following paragraphs .
1 . 05. Mamaroneck and Sheldrake Rivers . The final array of plan—
ning objectives for the Mamaroneck and Sheldrake Rivers are listed
below:
a. Reduction of the flood hazard and associated urban flood
damages in the Village and Town of Mamaroneck.
b. Preserve and maintain the resources of the existing stream
environment.
C. Preserve existing open space areas and associated recrea-
tional opportunities .
1. 06 . Byram River. The final array of planning objectives for the
Byram River basin are listed below:
a. Reduction of the flood hazard and associated urban flood
damages in the Town of Greenwich, Conn. and Village of Port Chester,
N.Y.
2
b. Preserve and maintain the resources of the existing stream
environment.
c. Maintain the existing water levels and associated recrea-
tional opportunities at Pemberwick Lake.
1 . 07. Description of Mamaroneck-Sheldrake River Basin Recommended
Plan. The real estate requirements and layout of the considered
plan of protection (Plan A) are shown on Table 2 and Figures 3 and
4 . The considered plan would provide for the construction of pro-
tective works almost entirely within the Village and Town of
Mamaroneck, with the segment along the Mamaroneck River between the
New England Thruway and Winfield Avenue lying along the boundary be-
tween the village and the Town of Harrison. No residential, com-
mercial or industrial structures would be acquired as part of this
plan. The considered plan is described below in segments .
1 . 08 . Village of Mamaroneck-Mamaroneck River. The plan of pro-
tection involves a combination of channel modification, retaining
walls and bridge replacement. As shown on Figure 3, the existing
channel of the Mamaroneck River would be widened and deepened from
a point downstream of Tompkins Avenue, upstream for approximately
10, 000 feet to just past Winfield Avenue. The modified channel
bottom along the Mamaroneck River would average 60 feet in width
from the lower limit of the plan upstream to a point about 300
feet past Jefferson Avenue, and 45 feet in width from this point
to the upstream limit of the channel works. The channel modifica-
tion would include the relocation of the confluence of the two
rivers to eliminate the two sharp bends in the existing alignment,
and a number of discontinuous retaining walls. These walls lie
along both banks from just below Valley Place upstream for 600 feet
to Station Plaza, along the right bank for 1, 150 feet from Nostrand
Avenue to First Street, along the left bank from First Street up-
stream for 1, 700 feet to Lewis Street, and for 300 feet on the
right bank at Willow Street. The plan additionally involves the
replacement of the Ward Avenue, Halstead Avenue, Station Plaza and
Hillside Avenue Bridges, and the replacement of the Valley Place
sewer bridge with an inverted syphon. Interior drainage is pro-
vided by a system of ditches and outlet drains through the line of
protection, and several areas along the streams would be filled and
graded. This plan is designed to protect against a flood with a
0 . 5 percent exceedence frequency (200 year flood) along the
Mamaroneck River downstream of the New England Thruway, and against
a flood with a 1 percent exceedence frequency (100 year flood)
along the Mamaroneck River upstream of the Thruway to Winfield
Avenue.
3
1. 09. Village of Mamaroneck-Sheldrake River . The Sheldrake River
would be diverted into a tunnel at Fenimore Road leading to the
Nest Basin of Mamaroneck Harbor. This tunnel diversion would con-
sist of three segments. For 1, 600 feet from the Sheldrake River to
Stanley Avenue the tunnel consists of a 15 ' x 15 ' box culvert; from
Stanley Avenue for 1, 450 feet to just north of Boston Post Road
the diversion consists of a 15. 5 foot diameter tunnel and thence
the tunnel consists of a 15 ' x 15 ' cut and cover box culvert for
400 feet to just south of Boston Post Road where the tunnel leads
to an open channel and stilling basin at the West Basin of Mamaroneck
Harbor. From the diversion inlet at Fenimore Road upstream to New Eng-
land Thruway (2 , 500 feet) the existing channel of the Sheldrake River
would be modified into a semitrapezoidal channel, with retaining walls
along the right bank. The tunnel diversion and modified channel
upstream of the inlet are designed to contain the Standard Project
Flood. * ( . 1 percent exceedence frequency (1, 000 year flood) ) along
the Sheldrake River. This diversion system would divert the total
flow of the Sheldrake River upstream of Fenimore Road into the tunnel.
The streamflow in the Sheldrake channel downstream of Fenimore Road
to the confluence with the Mamaroneck River would be comprised of the
incremental runoff which enters this reach of stream and the existing
capacity of the lower Sheldrake River would be maintained for this
purpose.
1. 10 . The proposed tunnel would be constructed by standard tunneling
techniques of drilling through rock, with appropriate grouting of
seams where necessary. The proposed tunnel from the Sheldrake River
would be protected by removable trash racks at the entrance and exit
of the diversion. These trash racks would be "L" shaped and consist
of steel bars spaced 6 inches on center for the full height of the
tunnel to protect against large timbers and other debris, and also
the entrance of children. Cleaning would be accomplished by manually
removing the structures from the diversion tunnel by mobile equipment,
dumping its contents into a truck and replacing the structure.
1 . 11 . Town of Mamaroneck-Sheldrake River. The plan of protection,
as shown on Figure 4, consists of a twelve foot wide concrete or rock
cut rectangular channel from a point approximately 250 feet upstream
of Rockland Avenue, at Brookside Place, downstream for approximately
1, 800 feet to a point about 300 feet downstream of Briarcliff Road.
The plan also includes a rock cut stilling basin approximately
300 feet downstream of Briarcliff Road, and a 32 foot long drop
structure and tie back levees at the upstream limit. The Forest
Avenue, Landsdowne Drive, Hickory Grove Drive and three driveway
bridges would be replaced, and low-lying areas along the stream
would be filled and graded. This plan is designed to protect against
a flood with a 1 percent exceedence frequency (100 year flood) .
* The Standard Project Flood is an estimated or hypothetical flood '
that might be expected from the most severe combination of meteor-
ological and hydrological conditions that are considered reason-
ably characteristic of the geographical region involved, exclu-
ding extraordinarily rare combinations .
4
1.12. Cost of Recommended Plan „ The total cost of the recommended
plan for Mamaroneck-Sheldrake, based on December 1976 price levels, is
$34,400,000. For the purpose of economic evaluation by comparing costs to
benefits, it is convenient to express the costs on an annual basis. The annual
cost of the plan is estimated at $2,230,000, including interest and amortization
computed on the basis of a 6-3/8 percent interest rate, and a project life of
100 years, and the annual costs of operation and maintenance. The breakdown of
first costs and annual charges for the considered plan along the Mamaroneck and
Sheldrake is shown on Table 1.
1 .1?. Benefits. The total average annual benefits attributable to the
considered plan are estimated at $3,360,000 including the damages
prevented by the improvement, adjusted to reflect future conditions, and
benefits from the advanced replacement of bridges and less frequent pavement
maintenance, and employment benefits. A summary of the benefits for the
considered plan along the Mamaroneck andSheldrake Rivers is shown in Table 1.
1.14. Economic Evaluation. The ratio of annual benefits to annual costs, and
excess benefits over costs determine the economic feasibility of a plan of
protection. The benefit-cost ratio for the considered plan is 1.4. A summary
of this evaluation for the considered plan is shown on Table 1. The considered
Plan, has been identified as the National Economic Development (NED)
plan, since it optimizes net benefits over costs.
1.15. Description of the Recommended Plan for Byram River. The considered
plan along the Byram River involves channel excavation, floodwalls and levees.
The real estate requirements and layout of the considered plan of protection
are shown on Table 2 and Figure 5, respectively. The channel of the Byram
River would be dredged for approximatley 700 feet downstream of the southern
U.S. 1 Bridge. The new channel would be 70 feet wide and the riverbed beneath
the two U.S. 1 Bridges would also be lowered. Rip-rap would be placed in the
bridge openings to protect against erosion. Upstream of the two U.S. 1 Bridges
a 50 foot wide rectangular channel running for 550 feet is proposed. From this
point upstream for 260 feet a semi-trapezoidal channel 50 feet wide with a wall
on the right bank would be constructed. From this point, approximately 400
feet below Den Lane to the proposed sill at Monica Street the channel will be
a 40 foot wide trapezoid. A floodwall 810 feet lone would be build on the
right bank between the two factories. A wall 550 feet long is proposed for the
left bank upstream of the southbound U.S. 1 Bridge. A levee would be built on
the left bank from the upstream end of the left bank wall and would continue to
the upstream limit of the proposed project at Rex Street, where it would tie
into the existing levee. It should be noted, that approximately 400 feet of
this existing levee would require minor modifications. An average raising of 2
feet along the length of the existing levee is reouired to guarantee closure
against the design flow. About 700 cubic yards of fill will be required to
make this minor adjustment to the existing levee. A concrete sill with a top
elevation of 6.0 feet Mean Sea Level is proposed for the mouth of Pemberwick
Lake to maintain its elevation during times of low flow. Ponding areas,
pumping stations, storm drainage interceptors and other associated interior
drainage facilties would be provided behind the levees and walls to carry
surface runoff from the area protected. This plan is designed to protect
against a flood with a 1 percent exceedence frequency (100 year flood).
5
1 . 16 . Costs of th` Recommended Byram River Plan. The total cost
of the considered plan, based on December 1976 price levels , is
$4 , 475, 000 . Total annual costs amount to $309, 000 , including in-
terest and amortization computed on the basis of a 6-3/8 percent
interest rate, and a project life of* 100 years, and the annual
costs of operation, maintenance and replacement. The breakdown of
first costs and annual charges for the considered plan along the
Byram River is shown on Table 1.
1 . 17. Benefits. The total average annual benefits attributable
to the considered plan are estimated at $488,300 , including the
damages prevented by the improvement, adjusted to reflect future
conditions , benefits from less frequent pavement maintenance, and
employment benefits. A summary of the benefits for the considered
plan along the Byram River is shown on Table 1.
1 . 18 . Economic Evaluation. As shown on Table 1,• the considered
plan of protection for the Byram River has a benefit-cost ratio of
1 . 6 . The considered plan has been identified as the National Ec:no-
mic Development (NED) plan, since it optimizes net benefits over
costs .
1. 19. Local Cooperation. In order for the Corps of Engineers to
make a favorable recommendation to Congress regarding a plan of
improvement, a letter of intent is required from local interests ,
indicating their willingness and ability to participate with the
Federal Government in the implementation of the plan. The Federal
Government would design and construct all works. Local interests
would agree to:
a . Provide without cost to the United States all lands,
easements , and rights-of-way, including suitable borrow and spoil
areas, as determined by the Chief of Engineers, necessary for the
construction of the project;
b. Accomplish without cost to the United States all altera-
tions and relocations of buildings, transportation facilities ,
storm drains , utilities and other structures and improvements made
necessary by the construction (excluding railroad bridges and
approaches and facilities necessary for the normal interception and
disposal of local interior drainage at the line of protection) ;
c. Hold and save the United States free from damages due to
the construction works , not to include damages due to the fault or
negligence of the United States or its contractors;
d. Maintain and operate all the works after com:letion in
accordance with regulations prescribed by the Secretary of the Army;
e. Prescribe and enforce regulations to prevent encroachment
on flood plain storage areas, channels, and rig.:_s-of-way as neces-
sary for the proper functioning of the project, and agree to take
appropriate measures to control development of the fringe areas not
protected by the improvement, to prevent an undue increase in the
flood damage potential , and to provide additional gravity outlets ,
pumping capacity or ponding areas due to the modification of , or
encroachment upon, such area by local interests;
6
f . Agree to adopt and enforce adequate regulations to main-
tain the existing channel capacity along the Sheldrake River down-
stream of Fenimore Road (Village of Mamaroneck only) ;
g. Publicize flood plain information in the areas concerned
and provide this information to zoning and other regulatory agencies
for their guidance and leadership in preventing unwise future de-
velopment in the flood plain and in adopting such regulations as
may be necessary to insure compatability between future development
and protection levels provided by the project;
• h. At least annually inform affected interests regarding the
limitations of the protection afforded by the project.
1. 20 . Mamaroneck and Sheldrake Rivers . In order to mitigate the
adverse effects of the structural works proposed for the Mamaroneck
and Sheldrake Rivers, the following measures will be incorporated
in the project:
a. In the upper Mamaroneck River area, the existing channel
generally will be widened by limiting the proposed channel excava-
tions only to one bankside, so as to decrease the removal of trees
and other vegetation. Investigations during preconstruction plan-
ning would determine if other areas exist within the project area for
which this technique is also suitable.
b. A pool and riffle low flow channel (which would approximate
in width the existing low-flow conditions) would be incorporated
into the entire channel areas to be modified, except in the portion
of the upper Sheldrake River where a flume or rock-cut channel is
proposed. For the upper Sheldrake River a shallow V-shaped pilot
channel would be incorporated into the plan.
C. Small log and rock dams may also be employed in the longer
riffle areas in order to create lowhead pools as an aquatic shelter
and habitat area.
d. Trees and shrubs eliminated by the structural elements
would be partially replaced through beautification measures and a
tree planting program.
e. During construction, control measures would be incorporated
to decrease any adverse effects to the water quality of the rivers
within the project area and at downstream areas . Measures to miti-
gate turbidity levels and to limit the erosion of denuded channel
slopes would include: (1) exposing the minimum area of land to
erosion that is practical at any one time during construction; (2)
• applying temporary mulch, with or without seeding temporary
vegetation, immediately after rough grading is completed; (3)
construction of temporary sediment basins or the placement of silt
screens or barriers to precipitate silt before it leaves the site.
7
f . For the tunnel diversion scheme, a trash rack or screen
would be installed to prevent boulders and other debris from
entering the diversion system. These structures would be positioned
at the upstream and downstream ends of the system, and would be
designed to permit manual removal from the channel, for cleaning
purposes .
1. 21. Byram River. Mitigation measures for the Byram River pro-
ject would include the erosion and sediment control measures (re-
fer to 1. 20 a above) . In addition, the following measures will also be
incorporated, should structural elements be implemented:
a. A pool and riffle low flow channel (which would approximate
in width the existing low-flow conditions) would be incorporated
for the entire length of the modified channel. Also, gabion wire
baskets or some other similar materials would be used for the crea-
tion of a diversified aquatic bottom habitat, at scattered locations.
b. A beautification and a tree planting program would be
implemented after construction so as to replace some of the trees
and shrubs removed as a result of levee and floodwall construction
or channel excavations .
c. At the mouth of Pemberwick Lake, a small dam or sill would
be constructed. This sill would preserve the present elevation of
water within the lake, thus preventing dewatering and degrading of
its fishery resources .
8
TABLE 1 - ECONOMIC EVALUATION OF THE CONSIDERED
PLANS OF PROTECTION (DECEMBER 1976 PRICE LEVEL)
ANNUAL TOTAL BENEFIT-
FEDERAL NON-FEDERAL TOTAL OPERATION, ANNUAL ANNUAL COST
FIRST COST FIRST COST FIRST COST MAINTENANCE COST BENEFITS RATIO
AND
_ REPLACEMENT
I. CONSIDERED PLAN FOR
MAMARONECK & SHELDRAKE
RIVERS - PLAN A _(NED)
PLAN
Mamaroneck & Sheldrake
Rivers - Village of
Mamaroneck 28,070,000 4,590,000 32,660,000 29,500 2,116,000 23840,000
Sheldrake River -
Town of Mamaroneck 1,460,000 280,000 1,740,000 3,500 114,000 220,000
TOTAL PLAN 29,530,000 4,870,000 34,400,000 33,000 2,230,000 3,060,000 1.4
lI . CONSIDERED PLAN FOR
BY RAM RIVER -
NED PLAN 3,540,000 935,000 4,475,000 23,000 309,000 488,300 1.6
TABLE 2
LAND ACQUISITION REQUIREMENTS FOR THE CONSIDERED PLANS OF PROTECTION (in acres)
PERMANENT
EASEMENT TOTAL
PERMANENT BETWEEN PERMANENT TEMPORARY HOMES
EASEMENT EXISTING EASEMENT EASEMENT PURCHASED
STREAMBANKS
I. MAMARONECK AND
SHELDRAKE RIVERS
VILLAGE OF MAMARONECK
Sheldrake River (incl.
diversion works) 2.0 0.1 2.1 2.9 -
Mamaroneck River down-
stream of N.Y.S. Thruway 11.0 7.8 18.8 7.2 -
Mamaroneck River upstream
of N.Y.S. Thruway 0.3 0.9 1.2 1.7 -
o TOTAL VILLAGE OF MAMARONECK 13.3 A 8.8 A 22.1 A 11.8 A -
TOWN OF HARRISON
Mamaroneck River 6.8 0.9 7.7 1.0 -
TOWN OF MAMARONECK
Sheldrake River 0.9 0.9 1.8 1.9 -
TOTAL MAMARONECK AND
SHELDRAKT RIVERS 21.0 A 10.6 A 31.6 A 14.7 A 0
II. BYRAM RIVER
Greenwich, Conn. 7.6 9.2 16.8 2.6 1
Port Chester, N.Y. 3.3 0.8 4.1 0. 3 -
TOTAL BYRAM RIVER 10.9 A 10.0 A 20.9 A 2.9 A 1
2 . ENVIRONMENTAL SETTING WITHOUT THE PROJECT
LOCATION
2. 01 . Mamaroneck and Sheldrake River Basins . The Mamaroneck River
basin including its tributary, the Sheldrake River, occupies a 23 . 4
square mile area of southeastern Westchester County, New York. In-
cluded within its boundaries are parts of the Cities of White Plains
and New Rochelle, parts of the Towns of Harrison, Mamaroneck, North
Castle and Scarsdale and part of the Village of Mamaroneck. This
watershed, draining into Long Island Sound, is shaped in the form of
flattened, elongated ellipse. Its longest dimension, 9. 2 miles , ex-
tends in a general north-south direction. Its topography consists
of gently rolling to mildly rugged hills, the lower slopes of which
form a dendritic arrangement of comparatively narrow valleys .
Ground elevations range from near mean sea level at the mouth of the
Mamaroneck River to about 500 feet above mean sea level in the north-
west corner of the basin. (Figure 1) .
2 . 02 . The Mamaroneck River rises downstream of Rye Lake, in the
northern section of Harrison at an elevation of 520 feet above mean
sea level. The river flows generally south for a distance of about
11 miles to Long Island Sound, which it enters through Mamaroneck
Harbor. The average slope of the Mamaroneck River is approximately
10 feet per mile. The Sheldrake River rises in the northeast por-
tion of Scarsdale, New York, at an elevation of 300 feet above mean
sea level. The river flows generally south-southeast for a dis-
tance of about 7. 0 miles and joins the Mamaroneck River at a point
about 0. 6 miles above its mouth. One major tributary, known as the
East Branch, enters the Sheldrake River at a point 1. 8 miles up-
stream of its junction with the Mamaroneck River. The average slope
of the Sheldrake River is approximately 25 feet per mile. The
Mamaroneck is tidal for about 0. 7 miles of its downstream section.
2. 03 . Mamaroneck Harbor is a small tidal waterway draining the pro-
ject watershed at the north shore of the Long Island Sound. It con-
sists of an inner constricted harbor and an outer open harbor , con-
nected by an inlet about 350 feet wide. The inner harbor is di-
vided into two basins, East Basin and West Basin, by a projecting
land area known as Harbor Island Park. The areas of the East and
West Basins are 53 and 40 acres respectively. The area of the
outer harbor is approximately 33 acres .
NAVIGATION
2. 04 Federal navigation projects have been constructed in the
estuaries of the Mamaroneck and Byram Rivers .
However, neither of these improvements has any effect on flood con-
ditions along the subject streams . The project at Mamaroneck Har-
bor, which was adopted in 1922 and modified in 1935 and 1960, con-
sists of a main channel from Long Island Sound to just below Boston
Post Road, a branch channel extending 300 feet northeast of the main
channel, two anchorages near the head of navigation in the East
Basin, and an anchorage in the West Basin with a connecting channel
to the main channel. The project at Port Chester Harbor, which was
adopted in 1910 and modified in 1930, consists of about 1. 7 miles of
channel from Long Island Sound to Mill Street, a turning basin,
breakwater at Byram Point, an anchorage near the breakwater and
fenders opposite Fox Island.
11
2 . 05 . Byram River Basin. The Byram River basin is located princi-
pally in Fairfield County, Connecticut and partly in Westchester
County, New York. The basin, draining 31. 0 square miles, encom-
passes areas in the Town of Greenwich, Connecticut and to a lesser
extent areas in the Towns of North Castle, Bedford, New Castle and
Rye, New York. The Communities of Pemberwick, Glenville and Round
Hill, Connecticut, and Armonk and Port Chester, New York are either
wholly or partly in the basin. The watershed of the Byram River is
roughly triangular in shape. Its maximum length extends 13 . 5 miles
in a general north-south direction while its width varies from 0 . 5
miles to 4 . 5 miles. The watershed is gently rolling with the ridges
of the hills running generally north and south. The watershed con-
tains lakes and marshes . Its many branching tributaries uniformly
drain the basin. The Byram River rises in the extreme southerly sec-
tion of the Town of North Castle, New York, and flows generally in
a southerly direction into Long Island Sound. The bed of the Byram
River slopes from its source at elevation 760 feet above mean sea
level to mean sea level. The average slope of the Byram River is
approximately 20 feet per mile. The downstream portion of the river
in Port Chester is tidal for a length of about 1. 3 miles. (Figure 5) .
POPULATION
2. 06. Mamaroneck-Sheldrake Study Area. The 1975 population of
Mamaroneck Village, New York is estimated at 18, 200, a 3 . 9% decrease
since the 1970 Census and a 4 . 8% decrease since the 1965 Special Cen-
sus . The unincorporated area ' s population within the Town of
Mamaroneck is estimated at 12, 800. Table 3 presents pertinent popu-
lation data concerning the study area. The Table indicates that both
Mamaroneck and Westchester County lost population between the years
1970 and 1975 . Although in the past, local, state, national, and
OBERS demigraphic projections have projected growth for the metro-
politan and near-by regions, many local forecasts and attitudes are
being revised, and a zero population growth, is either in effect or
is being encouraged. The Mamaroneck area would seem to be one of
these areas. In this area a relatively slow rate of residential con-
struction combined with decreasing household size has caused recent
population decreases. Stabilizing of household size can be expected
in the future. No growth, therefore, is forecast for the Village and
Township of Mamaroneck and the Village of Larchmont.
12
TABLE 3 - TOTAL POPULATION
MAMARONECK VILLAGE, MAMARONECK TOWN
AND SELECTED AREAS
Mamaroneck (v) Mamaroneck (U*) Larchmont Westchester
1960 17, 673 11, 763 6, 789 808, 891
` 1965 19 , 074 12, 357 6, 860 853, 198
Percent
Increase
1960-65 7 . 9 5. 0 1 . 0 5. 5
1970 18, 909 13, 002 7, 203 894, 104
Percent
Increase
1965-70 -0 . 9 5. 2 5. 0 4 . 8
Percent
Increase
1960-70 7. 0 10. 5 6 . 1 10 . 5
1975 18, 200 12, 800 6 , 900 890, 000
Percent
Increase
1970-75 -3 . 9 -1. 6 -4. 4 -0 . 5
Percent
Increase
1965-75 -4 . 8 3 . 6 0. 6 0 . 4
Source: U. S . Census (1960 & 1970) , and Village of Mamaroneck.
*Denotes the unincorporated area within the Town of Mamaroneck .
2. 07 . Byram River Study Area. The 1974 population of the Town of
Greenwich, Connecticut is estimated at 63, 100. The population of
Port Chester, New York is estimated at 26 , 500. Table 4 presents
pertinent population data and trends concerning the Byram River
study area. The population decrease in the New York portion between
1970 and 1975 because of decreasing household size. Household size
can be expected to stabilize in the future. Again as with the case
of the near-by Mamaroneck-Sheldrake study area population growth
trends have been decreasing on local and county levels . This trend
is also true for the entire New York Standard Metropolitan Statistical
Area of which these study areas are essentially a part. Recent pro-
jections by the U. S. Census Bureau and the Connecticut South-Western
Regional Planning Agency, for example, have projected a total popu-
lation of 65, 000 and 68, 500 in the years 1980 , and 1990 respectively,
for the Town of Greenwich.
13
Table 4 - Population, Port Chester, New York; and Greenwich, Conn.
Port Fairfield
Chester Greenwich County
1950 23 , 970 40, 835 504 , 342
Per Cent Change 4. 2 31. 7 29. 5
1950-1960
1960 24 , 960 53, 793 653 , 589
Per Cent Change 3. 3 11. 1 21. 3
1960-1970
1970 25, 803 59, 755 792, 814
Per Cent Change 2. 8 5. 4 3 . 4
1970-1974*
1974* 26 , 500 63, 100 819, 700
Source: U. S. Census Bureau and The Population of Connecticut:
Town and County Fact Book, 1970 , by T. E. Steahr, V. Bolduc, and
C. Skambis . Storrs Agricultural Experiment Station Bulletin 426 ,
February 1974 .
* Estimated Data
MANUFACTURING AND EMPLOYMENT
2 . 08. Mamaroneck Town and Village. Statistics for employment for
the Town and Village of Mamaroneck, New York resemble the diversity
found on the county level (Table 5) . Residents are employed in such
fields as construction, manufacturing, communications , utilities ,
various wholesale and retail trade establishments and other services ,
such as the health, educational and professional fields . A total
work force of approximately 8, 200 was reported in 1970 (Employment
Statistics, New York State Dept. of Labor) . The 1974 , New York
State Industrial Directory lists some 26 industries of various kinds
in Mamaroneck, with a total work force of over 1, 700 . All of these
reported industries are located within the Village of Mamaroneck,
and not in any of the unincorporated Town area. Employment statis-
tics are presented in Table 5.
14
TABLE 5 - LABOR FORCE - EMPLOYMENT AND UNEMPLOYMENT
_ Mamaroneck, N.Y. Westchester County
1960 1970 1960 1970
AGRICULTURE, FORESTRY, FISHING 137 132 2,774 3,130
MINING 8 6 487 611
CONSTRUCTION 594 567 20,399 21,736
MANUFACTURING 1,562 1,626 72,128 77,696
RAILROADS 29 18 4,714 2,193
TRUCKING-WAREHOUSING 61 56 2,613 2,915
OTHER TRANSPORTATION 160 95 4,329 6,007
COMMUNICATIONS 139 121 6,731 8,953
UTILITIES & SANITARY SERVICES 166 143 4,514 6,343
WHOLESALE TRADE 288 501 18,649 18,976
RETAIL TRADE 1,107 1,226 43,444 55,089
OTHER SERVICES 3,232 3,598 149,029 169,468
FINANCIAL (680) (465) (30,341) (26,261)
HEALTH (135) (333) (8,833) (24,548)
EDUCATIONAL (345) (736) (19,195) (33,219)
PROFESSIONAL (387) (381) (17,388) (18,404)
PUBLIC ADMIN. (258) (344) (13,082) (17,981)
MISC. (1,427) (1,339) (60,190) (49,055)
TOTAL EMPLOYMENT 7,363 8,089 329,811 373,117
UNEMPLOYED 248 185 10,321 9,398
TOTAL LABOR FORCE 7,611 8,274 340,132 382,515
Source: General Social and Economic Characteristics, New York, 1960
1970 Bureau of the Census.
15
2. 09 . byrm Study Area. Employment statistics for the Port
Chester, New York, and Greenwich, Connecticut area are listed in
the attached Table 6. In general, the residents , of the com-
munities are employed in such fields as publishing, research, metals
fabrication, baking products, construction, and wholesale and retail
trades . A total work force of some 25, 300 was reported for the Town
of Greenwich in 1970, while about 11, 500 people constitute the work
force in Port Chester, according to data from the U. S . Department of
Commerce. Both the Byram River and the Mamaroneck-Sheldrake River
basins are in areas of substantial unemployment. In March 1977, the
rate of unemployment in Westchester County, New York was 7 . 7% and in
Connecticut portion of the Byram River basin the unemployment rate
was above 6% .
CLIMATE
2. 10 . Mamaroneck, Sheldrake and Byram River Basins . In general,
the climate in the Region ot the two study areas is similar to
that reported from La Guardia Airport in New York City. Both
basins are located within a 25 mile radius of the airport and the
climatic differences within these short distances are considered
minimal . The climate, despite its nearness to the ocean and the
numerous bays and rivers nearby, more closely resembles the con-
tinental type than it does the maritime type. The areas modified
continental climate follows from the fact that weather conditions
affecting the New York City region usually approach from a westerly
direction, not from the ocean in the east. It should be noted, how-
ever, that the oceanic influence is by no means entirely absent.
During the summer, local "sea breezes" , i. e. winds blowing onshore
from the cool water surface, often moderate the afternoon heat . In
winter, coastal storms, accompanied by moist easterly winds , produce
on occasion, considerable amounts of precipitation.
2. 11. The mean annual temperature of the area is approximately 53
degrees Fahrenheit. Winter temperatures average about 30 degrees
Fahrenheit and summer temperatures average about 75 degrees Fahren-
heit. The extreme temperatures recorded at La Guardia included 2
degrees below zero as the record low and 107 degrees above zero was
observed as a record high. The prevailing winds in the area are
from the northwest and have an average velocity of 14 to 15 miles
per hour.
PRECIPITATION
2. 12. Mamaroneck, Sheldrake and Byram River Basins . Data on pre-
cipitation is available from eleven stations in and around the study
area. The longest period of record at these New York stations dates
back to 1891 at Bedford Hills, New York. Based on observed data, the
average annual precipitation for the basins being studed is 45 . 6
inches. The observed extreme values at individual stations were
66 . 98 inches in Bedford Hills in 1901 and 25 . 83 inches at Maple
Moor, White Plains, New York in 1965. The monthly extremes in-
clude a total rainfall of 16. 64 inches in October 1955 and 12 . 99
inches in September 1975 at Bedford Hills while only a trace of rain-
fall occurred at the same station in November 1917 . The distribu-
tion of precipitation is fairly uniform throughout the year with
slightly higher amounts reported during the summer months . The
average annual snowfall recorded at Scarsdale, New York is approxi-
16
TABLE 6 - LABOR FORCE - EMPLOYMENT AND UNEMPLOYMENT
Greenwich, Conn. Fairfield County Port Chester
1960 1970 1960 1970 1960 1970
AGRICULTURE, FORESTRY, FISHING, MINING 404 480 3,146 3,446 106 29
CONSTRUCTION 1,010 1,574 15,843 17,954 821 763
MANUFACTURING 5,751 5,430 102,510 115,374 3,564 3,382
WHOLESALE TRADE 570 1,144 7,512 13,668 396 400
RETAIL TRADE 2,251 3,436 32,684 50,011 1,659 2,149
TOTAL SERVICES 11,506 13,259 101,805 128,584 4,101 4,738
RAILROAD & RWY EXPRESS SERVICES (82) (34) (1,345) (764) (60) (31)
TRUCKING & WAREHOUSING (77) (199) (2,080) (2,935) (77) (115)
OTHER TRANSP. (271) (440) (2,119) (3,985) (107) (83)
COMMUNICATIONS (257) (293) (3,130) (4,248) (119) (222)
UTILITIES AND SANITARY SERVICES (271) (335) (2,985) (4,438) (171) (224)
FINANCE (2,488) (2,266) (16,578) (16,630) (440) (510)
v HEALTH SERVICES (546) (1,272) (6,343) (16,319) (295) (740)
EDUCATION (1,270) (2,536) (11,533) (24,343) (426) (641)
PROFESSIONAL SERVICES (1,214) (1,107) (9,332) (11,583) (359) (405)
PUBLIC ADMINISTRATION (629) (727) (7,576) (10,828) (311) (401)
OTHERS (4,401) (4,050) (38,784) (32,591) (1,736) (1,366)
TO1AL 21,492 25,323 263,500 329,037 10,647 11,461
UNEMPLOYED 443 615 10,296 10,499 469 340
TOTAL LABOR FORCE 21,935 25,938 273,806 339,536 11,116 11,801
Source: General Social and Economic Characteristics Connecticut, U. S. Department of Commerce 1960 and 1970.
mately 39 inches with a water equivalent of about 4 inches . The
snow season extends from November through April.
STREAM FLOW AND RUNOFF
2. 13 General. Runoff records are available for the stream gage
operated by the United States Geological Survey on the Mamaroneck
River at Mamaroneck, New York. The Byram River watershed is un-
gaged, however, the basic peak runoff data was developed through an
analysis of the steam gage at Blind Brook at Rye, New York. The aver-
age annual discharge for the Mamaroneck River recorded at the stream
gage for a period of record dating back to 1943 is 32. 1 cubic feet
per second (which is equivalent to about 18 . 6 incles of runoff or
about 42 percent of the estimated average rainfall) . Additional
stream data are contained in Table 7 (Additional more detailed in-
formation concerning the hydrology of the projects may be found in
the Feasibility Report which is available for review at the New York
District Office) .
STORMS
2 . 14 . Mamaroneck, Sheldrake and Byram River Basins . Storms occur-
ring in the study areas may be classified as thunderstorms , cloud
bursts, or extratropical storms, transcontinental or cyclonic storms
and West Indian hurricanes. Thunderstorms occur generally in the
summer and are usually of high intensity but of short duration. The
storm of July 1938 , which covered southeastern New York, Connecticut,
New Jersey and Massachusetts, and the storm of August 1927 were of
this type. Cloud bursts or extratropical storms generally occur in
the summer and fall and are usually caused by an overrun of tropical
marine air masses above colder air masses stabilized over the land .
The transcontinental or cyclonic storms occur generally in the
winter and spring . These storms originate in the southwestern states
and travel east and northeast causing heavy rains which result in
floods over wide areas. Hurricane storms originate in the Carribean
area and proceed northward along the Atlantic Coast. They are ac-
companied by violent winds and torrential rains .
2. 15 Storm of 14-18 October 1955. A cold front moved into eastern
Pennsylvania and southern New York on the morning of 13 October 1955
and became stationary with a coastal wave moving northward accom-
panied by moderate to heavy rains on the 14th and 15th of October.
The center drifted slowly northward bringing an abundance of rains
which continued in the northeast through the 16th. Concurrently,
progress of an extratropical storm accompanied by heavy rainfall
extended through the 17th of October. The maximum daily rainfall
recorded in the vicinity was 4. 64 inches at Scarsdale, New York .
During the storm period total rainfall of 9 . 66, 7 . 92 and 9. 01 inches
was recorded at Putnam Lake, Conn. , White Plains , N.Y . and Pleasant-
ville, N.Y. respectively, of which 6. 68 inches fell within 24 hours
at Putnam Lake.
18
TABLE 7
STREAM DISCHARGE DATA
Mamaroneck River Blind Brook
Stream Gage at at
Period of Record Mamaroneck, N.Y. Rye, N.Y.
Drainage Area (sq. mi.) 23.4 9. 20
Period of Record 1944-1975 1944-1975
Annual Discharge
Maximum Water Year 1972 1972
c.f.s. 58.1 26.30
C.S.M. 2.48 2.86
inches 33.70 38.91
Minimum Water Year 1950 1966
c.f.s. 16.70 7.00
C.S.M. 0.71 0.76
inches 9.71 10.33
Average Year
c.f.s. 32.7 15.2
C.S.M. 1.40 1.65
inches 18.62 22.13
Monthly Discharge
Maximum Month June 1972 June 1972
c.f.s. 205.0 92.0
C.S.M. 8.76 10.0
inches 9.77 11.16
Minimum Month Sept 1965 Sept 1948
c.f.s. 0.95 0.65
C.S.M. 0.041 0.079
Daily Discharge
Maximum Day 19 Jun 1972 19 Jun 1972
c.f.s. 2,340.0 1,070.0
C.S.M. 100.0 116.30
Minimum Day 30 Sept 1965 5 July 1953
c.f.s. 0.10 0.12
C.S.M. 0.004 0.013
Peak Discharge
Day 27 Sept 1975 19 Jun 1972
c.f.s. 4,260.0 2,320.0
C.S.M. 182.1 252.2
19
2. 16 Storm of 26-29 August 1971. Tropical storm "Doria" originated
in the Bahama Islands and moved northward along the North Atlantic
Coast. As she crossed the coastal portions of North Carolina and
southeastern Virginia, her speed increased to 20-25 knots . The storm
center reached southwestern Connecticut by 0800 on 28 August. At the
Scarsdale rain gage adjacent to the Sheldrake River Basin, a total
rainfall of 6. 54 inches was recorded between the 27th and 28th of j
August. At the White Plains Airport rain gage adjacent to the Byram
river Basin a total rainfall of 5 . 70 inches was recorded for the 27th
and 28th of August.
2. 17 . Storm of 16-22 June 1972. Tropical storm "Agnes" was the re-
sult of a tropical storm depression that originated south of the Gulf
of Mexico and moved northward over land carrying massive amounts of
moist air. At the Scarsdale rain gage in the Mamaroneck and Sheldrake
River Basins a total of 4 . 83 inches was recorded on the 18th and 19th
of June. The Mamaroneck and Sheldrake River basin-wide total rain-
fall was 4. 52 inches . For the Byram River the basin-wide total rain-
fall was 5. 49 inches .
2. 18 . Storm of 19 September to 27 Septe_-tuber 1975 . During the
later part of September 1975, the northeastern United States , parti-
cularly the states of New York and New Jersey were struck by severe
thunderstorm activities. On October 3, 1975 the President of the
United States declared various Counties in New York State, including
Westchester as major disaster areas ; thereby, making these Counties
eligible for Federal assistance under the Provision of Public Law
93-288. At the White Plains Maple Moore gage, a total rainfall of
9 . 49 inches was reported between 21 to 26 September 1975 causing
major floods on many Westchester County streams . The Byram River
basin-wide rainfall was 10 . 62 inches .
STORM DAMAGES
2. 19 . General. The most damaging floods of record resulted from
the storms of 15-16 October 1955, 16 June 1972, 26-27 September
1975. Based on December 1976 price levels , the damages within the
Mamaroneck and Sheldrake Rivers Basin for the June 1972 and Septem-
ber 1975 floods are estimated at $3, 500 , 000 and $19 , 700 , 000 respec-
tively. The damages within the Byram River Basin for the October
1955 and June 1972 floods are estimated at $1, 334, 000 and $483, 000
respectively. However , a recurrence of the October 1955 flood
along the Byram River would result in flood damages of $1, 066 , 000
when considering existing conditions of development and the damages
that would be prevented by the existing Corps ' project at Pember-
wick, Connecticut. Other floods occurred in October 1877 , September
1882 , July 1889 , October 1903, March 1936 , July 1938 , September 1938 ,
July 1942, August 1942, September 1944 , May 1946 , March 1953 ,
August 1955, August 1960 , April 1961, March 1962 , August 1971 , and
September 1974. Flood damages within the subject basins are de-
scribed in the following paragraphs.
20
2. 20. Mamaroneck and Sheldrake Rivers Basin. In the Village of
Mamaroneck, New York, the flood problem can be exemplified by the
damages resulting from the June 1972 flood. Hundreds of residents ,
employees, and school children were evacuated by boats and trucks
as the Mamaroneck and Sheldrake Rivers overflowed their banks , inun-
dating local streets and numerous homes and business establishments .
Areas inundated in the Village of Mamaroneck from this flood in-
clude approximately 107 acres of industrial, commercial and residen-
tial property. Along the Mamaroneck River the flood damage area is
located on both banks between Ward Street and First Street. From
First Street upstream to the New England Thruway damages are con-
fined to the left bank and in the reach between Chestnut Avenue and
the Joint Waterworks dam, the village flood damage area lies on the
right bank. Along the Sheldrake River the flood damage area is on
both banks between the confluence with the Mamaroneck River and Feni-
more Road. Between Fenimore Road and the village line the damage
area lies on the right bank. During the June 1972 storm, 26 indus-
trial structures, 33 commercial establishments , 5 public buildings
and 207 dwellings were flooded. Columbus Park was completely sub-
merged. The industrial park was inundated to a depth of two feet
and many businesses were not able to resume production for a week or
more. Hardest hit industrial areas were at the Sealectro Corpora-
tion plant on Hoyt Street, where 60 employees were evacuated, and
the Bordow Corporation, located at Mamaroneck and Jefferson Avenues ,
which had several feet of water in its buildings . The main floors of
many dwellings between Mamaroneck Avenue and the Mamaroneck River
were flooded to a depth of one foot. Other areas with significant
damages include the residential and business areas of Washington-
ville section of the Village of Mamaroneck, the residents who live
along the upper Mamaroneck River on Chestnut and Winfield Avenues
in the village. Along Chestnut Avenue basements were flooded to a
depth of 5 feet causing severe content damage. Several homes along
Winfield Avenue suffered first floor flooding when the Winfield
Avenue Bridge was overtopped. Total damage from the June 1972 flood
in the Village of Mamaroneck is estimated at $3, 270 , 000 . The record
flood of September 1975 produced a stage approximately 1. 5 feet
higher at the subject area and resulted in damages estimated at
$19, 000 , 000.
2. 21 . In the Town of Mamaroneck, residential areas along the
Sheldrake River in the town have suffered recurring damages in re-
cent years. Areas inundated in the Town of Mamaroneck from the
September 1975 flood of record include approximately 21 acres of
residential property. The flood damage area is located on both
banks of the Sheldrake River from Hickory Grove Road to the Bonnie
Briar Country Club. During the September 1975 flood, 80 dwellings
including 8 homes along the East Branch, were flooded. The homes
along the main stream suffered severe structural and property
damage. In many of these buildings the concrete basement floor
slabs cracked and welled up. The equipment in a dentist' s office
was badly damaged. The total damage for the September 1975 flood
is estimated at $529, 000 . The floods of August 1971 and June 1972
were approximately equal in magnitude and each produced about
$181, 000 in damage.
21
2 . 22 . Areas inundated in the Town of Harrison, New York during the
June 1972 flood included the Maple Moor Golf Course, the Hutchinson
River Parkway and approximately 9 acres of residential property
along the left bank of the Mamaroneck River, from West Street up-
stream to Winfield Avenue. In this second reach, the Mamaroneck
River forms the boundary with the Village of Mamaroneck, and this
area lies directly across the Chestnut Avenue area in the village.
During the June 1972 storm 10 dwellings at this area experienced
basement and grounds flooding resulting in damages estimated at
$20, 000. The September 1975 flood of record resulted in damages
estimated to be $65, 000 at this area. Damages also occurred along
the East Branch of the Mamaroneck River during the June 1972 storm.
During this flood, and also the September 1975 flood, approximately
6 homes on Pine Hurst and Tamershan Drives and Duxbury Lane suf-
fered basement and grounds damage. Additionally during the June
1972 flood a dry stone wall near the foot of Crocker Lane dam on
the East Branch was damaged. The flood of June 1972 resulted in
approximately $45, 000 of damage along the East Branch of the
Mamaroneck River in Harrison.
2 . 23 . Byram River Basin. In Greenwich, Connecticut and Port
Chester, New York, the flood problem can be exemplified by the
damages resulting from the flood of June 1972. Areas inundated in
the Greenwich-Port Chester area from this flood include approxi-
mately 39 acres of commercial, industrial and residential property .
The flood damage area is located between West Putnam Avenue (U.S . 1)
and Rex Street on the left bank, and between West Putnam Avenue and
the old Homelite factory on the right bank. During the June 1972
storm, 2 industrial structures, 3 commercial establishments and 66
residences were inundated. Several homes had flood waters above
the main floor. In most cases damage resulted from 4 to 6 feet of
water in the basement. The basement flooding caused some severe
structural damage but mainly the damage was confined to contents
such as washing machines, machine tools, stored clothes and the like.
Several people lost cars which had been parked in their garages .
Total damages for the June 1972 flood are estimated at $483 , 000 . The
October 1955 flood of record produced stages approximately 2. 3 higher
than the June 1972 storm. In addition to damage at the Greenwich and
Port Chester areas described above, the 1955 storm resulted in damage
to twelve town roads in North Castle, New York and several dwellings
in Riversville (Town of Greenwich) , Connecticut. A recurrence of the
October 1955 storm would result in flood damages estimated at
$1, 066 , 000.
GEOLOGY
2. 24 . Mamaroneck and Sheldrake Rivers . Lower Westchester County
is part of the New England Highlands physiographic province which
in the project area is located between the Atlantic Coastal Plain
province on the east and the New Jersey and Hudson Highlands on the
west. The ridges, valleys and streams tend towards the north to
northeast. The eastern edge of the county is joined by the western
edge of the Continental Shelf of the United States which was glacially
scoured to form Long Island and the Long Island Sound. Geologic units
within the area are composed of both a complex association of con-
solidated rocks and unconsolidated sediments. The principal rocks
which underlie the topography of the surrounding region include:
the Fordham gneiss, Manhattan schist, Inwood limestone, (marble or
dolomite) and the massive granite or diorite dikes .
22
2 . 25 . Byram River. The geology of the Byram River Basin is similar
to other parts of the Westchester-Fairfield County Region. The pro-
ject area is located in the Upland Province of the Appalachian High-
lands physiographic division. The geological uplifting of this part
of Appalachian system was followed by a long period of erosion which
reduced the area to a dissected peneplain. During the subsequent Pleis-
tocene time the glaciers advanced repeatedly covering the area.
Thick deposits of till, unsorted and unconsolidated ranging from
clay to boulders was placed by the ice and mantled most of the area .
During and after the melting of the ice, gravel, sand and silt were
deposited in the stream valleys. At some places, these deposits
blocked the stream channel forming small lakes. As a result of
these geological phenomena, a relatively thin mantle of glacial till
now overlies a bed of hard impervious rock. In many places , the
channels of the Byram River run directly over this rock. Ground
wells in this Region are generally poor producers due to the till
material.
SOIL EXPLORATIONS
2 . 26 . Mamaroneck and Sheldrake Rivers Basin. During the summer of
1945, and June of 1976, foundation conditions along the stream were
investigated. The subsurface explorations consisted of drill holes ,
auger holes and test pits. The soil profile along the Mamaroneck
River consisted, in general of a small varying layer of topsoil
followed by layers of course to fine sand mixed with varying amounts
of silt and gravel. In the test drilling, bedrock was encountered
in depths ranging from about 12 to 22 feet below the surface. Soil
profiles for the Sheldrake River were similar to the conditions
found for the Mamaroneck, however, bedrock is exposed at several
areas adjacent to the stream. These rock outcroppings are parti-
cularly visible along the Sheldrake River upstream of Landsowne
Road in the Town of Mamaroneck.
2. 27 . Byram River Basin. During June of 1976 the foundation condi-
tions along the stream were investigated. The subsurface explora-
tions consisted of 6 drill holes taken within the proposed project
limits. The soil profile generally consists in the upper layers of
a fine brown silt or a dark grey or brown sand. In the upper project
area (i .e. upstream from the vicinity of Den Street) , the lower
strata material generally consisted of coarser materials chiefly a
brown sand with traces of gravel or of a grey sand with varying
amounts of gravel and silt. In the lower project area, the lower
strata materials were generally found to be finer in size, consist-
ing mostly of a brown fine sand or a brown-fine to a medium sand
with traces of silt material. The depths of the drill holes varied
from 14 feet to 24 feet below the surface and bedrock was not en-
countered at these depths.
WATER SUPPLY
2. 28. Mamaroneck and Sheldrake Rivers Basin. There are two major
reservoirs in Westchester County, the Croton Reservoir and the Ken-
sico Reservoir, both of which are part of the New York City Water
23
Supply System. By agreement with New York City, Westchester County
is guaranteed water from the New York City system in volumes equiva-
lent to the per capita rate of consumption in New York City, cur-
rently 150 gallons per day. However, the same agreement stipulates
that the quality of water is not guaranteed and that if New York
City decides not to continue to supply water to itself it can also
discontinue service to Westchester County. Since 1927 the West-
chester Joint Water Works has served the Towns of Mamaroneck and
Harrison and the Village of Mamaroneck, who own the system. The
principle storage facilities were the Larchmont Reservoir and the
Mamaroneck Reservoir, both located upstream of the project area.
During the last several years, however, these supplies have not been
used and are presently only standby facilities . The project area is
supplied primarily by water drawn from the New York City - Delaware
Aqueduct system through the Mamaroneck Water Company. +
2. 29. Byram River Basin. The public water supply for both Green-
wich, and Port Chester is supplied by the Greenwich Water Company.
The Greenwich Water Company obtains its supply principally from
the Byram River Basin. Water is diverted from the upper reaches of
the River and is stored in the Putnam Lake and Rockwood Lake Reser-
voirs . The entire southwestern Connecticut region has been gene-
rally described as having substantial water supply resources to
handle present and future needs of the region.
GROUNDWATER
2. 30. Mamaroneck, Sheldrake and Byram Rivers Basin. The water-
bearing strata in the Westchester-Fairfield Counties region may be
divided into unconsolidated surficial deposits and consolidated
bedrock. The unconsolidated deposits cover the bedrock in most of
the Counties and range in thickness from a few feet on hills to more
than 200 feet in the larger valleys. These deposits range from clays ,
which will produce only meager quantities of water, to coarse sand and
gravel, capable of yielding several hundred gallons per minute to a
well. As stated earlier, however, both study areas are served by
public water supplies derived from surface sources outside of the
immediate areas. It is probable that the few domestic and industrial wells
located within the project areas are currently not in use or are
used only for non-potable purposes. Local permits are not required
for the installation of wells providing they are used for non-
potable uses. Therefore, records generally do not exist which de-
lineate to number or location of wells drilled within the study
areas or to their present status.
WATER QUALITY
2. 31. Mamaroneck and Sheldrake Rivers Basin. The Mamaroneck and
Sheldrake Rivers are classified as D streams by the State of New York
within the project areas and are considered significantly degraded.
The lower tidal portion of the Mamaroneck River is class I while the
East and West Basins of Mamaroneck Harbor are classified as SB waters ,
closed to shellfishing (copies of the applicable State water quality
standards appear in the Appendix) . United States Environmental Pro-
tection Agency discharge permits have been issued to local industries
24
that discharge wastes primarily into the Upper Mamaroneck River and
into the Harbor area as well. In addition to industrial discharges
local storm water drains also discharge into the Sheldrake and
Mamaroneck Rivers. Visual inspections of the stream indicate that,
in general, they are devoid of obstacles and garbage debris ,
and present an aesthetically attractive appearance particularly
in the upstream residential areas . The rivers are shallow
during times of normal flow with depths ranging from about 1 to
5 feet. The river bottoms are generally composed of mud and silt,
although the upper Sheldrake River is generally more rocky consist-
ing of gravel or stones . One prominent negative feature noted, how-
ever is that throughout the project area the water exhibits a signifi-
cantly murky, greenish-brown appearance. Also, in the vicinity of
the rivers ccnfluence area and downstream, there is increasing evi-
dence of water quality degradation due to the presence of oil and
floating debris. The discharges into the Harbor from the Mamaroneck
Sewage Treatment Plant along with storm water discharges from the
more urbanized village area are probably the main contributing fac-
tors in the water quality degradation in the harbor. The water
quality of the Mamaroneck Harbor area is also determined by the
quality of waters flowing into the harbor (including the salt
marsh wetlands of Guion and Otter Creeks) from the surrounding
watershed, by discharges from boats and surrounding shoreside faci-
lities and by the movement of waters into the harbor from Long
Island Sound. The existing water quality condition within the
project area is expected to continue due to the urbanized nature of
the upland areas. The proposed upgrading of the municipal sewage
treatment facility at Harbor Island would be expected to decrease
the pollution load within Mamaroneck Harbor.
2. 32. Only limited water quality data has been collected for the
river basin. Data collected by the United States Department of the
Interior, and the U. S. Environmental Protection Agency (water
quality - STORET System) generally conforms to the standards for
Class D waters. Data has been collected on the Mamaroneck River at
the stream gaging station located just below the confluence of the
Mamaroneck and Sheldrake Rivers . Dissolved nitrates , solids , and
sulfates were low (reported at 4 . 5 mg/1, 36 . 0 mg/l and 92 . 0 mg/l,
respectively) . The Ph ranged from a high value of 8 . 2 to a low of
6. 9, and dissolved chlorides were less than 100 mg/1 . According to
a recent draft report on water quality management for the region,
published by the New York State Department of Environmental Con-
servation, the basin is a prime contributor of high bacteria counts
in Mamaroneck Harbor. High coliform and fecal coliform counts have
been recorded at the mouth of the Mamaroneck River and at the up-
stream Mamaroneck Reservoir as well.
2. 33. Sediment Data. In addition to the surface water quality data
discussed in the above paragraphs, bottom sediment data are available
from an ongoing United States Department of the Interior, Water Re-
sources Division study of selected streams and lakes in Westchester
County. Additional data is also available from a New York District
Corps of Engineers sampling program regarding Federal navigation, pro-
25
jects (refer to paragraph 2. 04) . This data presented in Tables 8 and
9 may give a better representation of stream water quality, since
water column sampling of certain parameters, particularly metals and
pesticides may vary widely with the flow of water. A review of the
data indicates that relatively high concentrations of arsenic, lead,
copper, and oil and grease material was present in each of the samples
taken in the Mamaroneck Harbor area (it should be noted that samples
2A and 2D were taken in the West and East Basins, respectively, while
the other samples were taken in the outer section of the Harbor) .
Higher concentrations were found in the inner Harbor samples . The
bottom samples taken in the Sheldrake River (Table 9) generally in-
dicated significantly lower levels of these toxic substances , how-
ever, relatively high levels of iron and phosphorus were reported.
2. 34. Byram River Basin. The Byram River is classified as a B
stream in the project area by the State of Connecticut. The tidal
portion of the stream is classified as SD waters and closed to shell-
fishing . The remaining freshwater portion of the River which lies
between the vicinity of the Putnam Avenue bridges downstream to the
tidewater is class D (copies of established state standards appear
in the Appendix) .
2. 35. The waters of the lower Byram have been degraded in the past
because of the numerous industrial and commercial discharges of
wastes into the waterway. In recent years some of the major sources of
discharges from commercial and industrial plants have been discon-
tinued as have been the municipal sewage discharges from the Town of
Greenwich. Significant discharges still occur, however, particularly
in the Port Chester Harbor area. Also, local storm water runoff
from the surrounding region draining into the River is another con-
tributing factor to water quality degradation for this study area.
Recent sampling by the Westchester County Department of Health con-
ducted between 1971-1975 have indicated that dissolved oxygen and
coliform bacteria levels have been regularly violated near the
mouth of the Byram. These violations have occurred both above and
below the Port Chester Sewage Treatment Plant. The lower 1 . 3 miles
of the Byram River is tidal and salt water intrusion normally
reaches up to the lower project limits . However, during extreme
high tide conditions, the tidal effects may reach well within the
project limits carrying pollutants to the upstream areas .
2. 36 . Sediment Data. Bottom sample data is also available for the
Byram River (see Table 8) where samples were taken at points below
the proposed flood control area, however, samples 1C and 1D were taken
at about points located 1. 1 miles and 1. 5 miles upstream of Byram
Point which is in the vicinity of the project area. A review of this
data indicates that the levels reported for arsenic, lead, copper ,
chromium, and oil and grease were high, however, the upstream samples
indicates considerably less polluted sediments. During the late ,
planning stages of this flood control study additional samples will
be taken at points upstream of the Putnam Avenue bridges .
26
I ,
TABLE 8 - SEDIMENT ANALYSIS OF BOTTOM GRAB SAMPLES
FROM INNER AND OUTER MAMARONECK HARBOR AND FROM PORT CHESTER HARBOR
MAMARONECK (MAY 1977) PORT CHESTER (MAY 1917)
2A 2B 2C 2D IA 1B 1C 1D
DRY WEIGHT ANALYSIS
Mercury (mg/kg) 2.13 1.22 0.96 1.03 0.96 1.16 0.17 0.25
Cadmium (mg/kg) 2.97 2.90 2.23 2.23 8.5 12.7 3.8 2.8
Arsenic (ug/kg) 10,094
8,561 7,294 10,633 6,398 4,563 3,678 2,082
Lead (mg/k@) 177.7 152.0 157.8 532.4 197.1 396.8 207.5 142.5
i
Copper " 263.5 150.2 119.1 242.3 206.9 238.1 57.4 42.8
Zinc " 421.6 225.3 205.4 400.2 425.9 502.6 220.7 134.4
Chromium " 65.1 80.5 44.7 91.8 127.8 123.0 45.9 28.5
Nickel " 36.6 39.3 31.3 45.9 57.2 56.9 37.5 15.1
%Water " 62.2 68.0 52.6 70.1 • 66.3 68.9 23.2 23.1
Oil 6 Grease " 8,530 71,456 43,502 96,616 5,693 8,262 4,540 10,280
Polychlorinated Biphenyls (PPM) . 01 0.1 -0.1 :0.1 .0.1 -0.1 0.1 :0.1
Total Organic Carbon 3.21% 4.11% 2.67% 5.33% 4.41% 4.79% 3.29% 1.33%
(Schwarzkouf Labs)
Loss on Ignition % 9.86 12.94 8.34 12.05 13.5 13.4 2.8 3.4
(relative to dry weight)
STANDARD ELUTRIATE TEST
• MAMARONECK PORT CHESTER
COMPOSITES- 2A/2D COMPOSITES- 1A/1D
Raw Elut. Raw Elut.
Cadmium (mg/1) 0.20 0.25 0.04 0.06
Total Organic Carbon of 18 20 <5 15
Cyanide (ug/1) 5 5 10 18
Total Kieldahl Nitrogen (mg/1) 0.59 30.58 0.38 9.14
Mercury (ug/1) 6.0 14.0 1.5 2.0
Nitrate Nitrogen (mg/1) 1.5 0.65 0.35 0.55
DDT (ng/ml) ='O.025 <'0.025 .0.025 <,0.025
v
w
Polychlorinated Biphenyls of • .0.025 0.025 <;0.025 <0.025
Source: U.S. Army Corps of Engineers, New York District.
TABLE 9 - WATER RESOURCES DATA -
ANALYSIS OF SAMPLES COLLECTED AT MISCELLANEOUS SITES
TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC
KFLL. NITRITE PHOS- ARSENIC CADMIUM CHRO- COPPER IRON LEAD MAA'GA- MERCURY PCH CARBON
NITRO- PLUS PHORUS IN IN MIUM 1N IN IN IN NESE IN 1N IN IN BOT-
GEN IN NITRITE IN BOT- BOTTOM BOTTOM BOTTOM BOTTOM BOTTOM BOTTOM BOTTOM BOTTOM BOTTOM TOM MA-
BOTTOM IN BOT. TOM MA- MA- MA- MA- MA- MA- MA_ MA- MA- MA- TERIAL
MAT. MAT. TERIAL TERIAL TERIAL TERIAL TERIAL TERIAL TERIAL TERIAL TERIAL TERIAL (C)
DATE SMG/KC I-LIMG/KG _!L9G G SUG/G) (UG/G _ (UGIG) UG/G) (UG G (UG/G) UG/G) UC KG SC/KG
MAMARONECK RIVER BASIN
SHELDRAKE RIVER AT QUAKER RIDGE ROAD, NEW ROCHELLE, NEW YORK (LAT 40 57 24 LONG 073 46 37)
Aug. 3, 1976 980 11 270 10 1 16 25 11000 140 1100 .1 300 9.3
SHELDRAKE LAKE AT INLET AT NEW ROCHELLE NEW YORK (LAT 40 57 13 LONG 073 46 37)
N
Nov. 17, 1976 -- -- -- -- -- -- -- -- -- — -- 0 --
00
SIIELDRAKE RIVER AT FERNWOOD AVE AT LARCHMONT NEW YORK (LAT 40 56 42 LONG 073 45 18)
Nov. 17, 1976 111 3.0 71 2 0 4 6 3100 39 150 .0 0 2.4
SHELDRAKE RIVER AT MAMARONECK AVE (LAT 40 57 12 LONG 073 44 18)
Aug. 3. 1976 290 8.3 150 5 1 13 270 8600 970 99 .0 0 8.9
Nov. 17, 1976 172 1.4 57 4 1 7 120 4600 100 110 .1 -- 5.3
Source: U.S. Geological Survey, Water Resources Division, Water Resources Data for New York, Water Year 1976
FISH AND WILDLIFE OF THE IAMARONECK AND
SHELDRAKE STUDY AREA
2 . 36x. Wildlife Habitat. The study area is situated in an essentially
urbanized flood plain area and as a result few wildlife habitat areas
remain, particularly in locations where the local homes or businesses
bound the streams on both sides. This is the case along the reach
of the Sheldrake River upstream of Briarcliff Road (see Figure 4) ,
and along the reach of the Mamaroneck River below Hillside Avenue
(see Figure 3) . While the wildlife habitat in the project area has
been limited or diminished by the areas suburban development,
there still remain lands which are relatively undeveloped . Numerous
aesthetically pleasing lightly to moderately w .oded zones are
located along the streams and elsewhere. Wildlife habitat areas
may be found along the lower Sheldrake River west of Fenimore
Road up to the vicinity of Rockland Avenue and along the Mamaroneck
River east of N. Barry Avenue. Within several of these reaches the
New England Thruway bounds the streams on one side leaving relatively
wide strips of undeveloped lands for wildlife habitat. In addition,
the close proximity of the project area to the near-by Bonnie Briar
and Winged Foot Country Clubs along with the Sheldrake Nature Trails
and Saxon Woods County Park, afford additional habitat areas for
wildlife.
2. 37 . Vegetation. The vegetation resources within the Mamaroneck-
Sheldrake project area are generally dominated by various wetlands
trees and shrubs along with numerous ornamental plants also present.
The following types of trees are present: willow, sweetgum, sycamore,
red maple, silver maple, white ash, white oak, black birch, black gum,
elm, alder, pussywillow, scotch pine and Norway spruce . Vines and
shrubs include poison ivy, wild blackberry, honeysuckle, viburnum,
wild rose, common bearberry, maleberry and grape . Also present in
the area native and domestic grasses , broadleaved weeds and goldenrod.
2 . 38 . Wildlife. A number of the Region ' s mammals can be found near
fields, including mice, moles and shrews . The racoon is fairly com-
mon in the wetter areas feeding on crayfish and snails . The longtail
weasel and the striped skunk also should inhabit this region . Such
woodland dwellers as the deer mouse, muskrat, woodchuck (ground hog) ,
chipmunk and squirrels are abundant. Black rats and Norway rats
are probably also present in this study area. The project area
also supports turtles, probably snapping turtles and spotted
turtles . There are some snakes, lizards , toads, salamanders and
numerous frogs although these reptiles and amphibians are not readily
seen. No threatened or endangered species is known to inhabit within
the project area.
2 . 39 . Birds . Although as mentioned previously the areas urbanizing
pressures have resulted in significant losses of suitable habitat
and food supply within the project area, but sufficient lands re-
main to support many resident birds , as well as , provide attrac-
tive resting spots for migrating or wintering species . Several of
these species are listed below, a more complete listing is given
in the Biology Appendix. These species include: mallard, black
duck, Canada goose, scaup , mute swan, green herron, red-bellied wood-
pecker, killdeer, yellow warbler, great horned owl, robins , cardi-
nals , blackbirds , sparrows and starlings .
29
2. 40. Fisheries Resources. The predominant forms of aquatic organ-
isms in the Sheldrake and Mamaroneck Rivers consist of bottom fauna
or benthos, flora and zooplankton. These form the basis of the food-
web, for the higher life forms including the fish species which are
important components of the aquatic ecosystem as secondary and ter-
tiary consumers . Coordination with the Fish and Wildlife Service of
the U. S . Department of the Interior and the National Marine Fisheries
Service of the U. S. Department of Commerce has indicated that only a
limited fishery resource is present. The fishery resources in the
streams are generally limited due to the following reasons : (a)
Shallow low flow conditions are encountered during most of the year,
(b) poor water quality in conjunction with insufficient flows are
generally nonconducive to fish propagation, particularly game species ,
and (c) relatively poor stream cover is found in the urban areas of
the basin. Some fishery resources are reported however , despite the
generally urban character of the basin. The most significant resources
are present in the larger waterbodies , such as Larchmont Gardens
Lake, and the upstream reservoirs . The Sheldrake River and the upper
reaches of the Mamaroneck River is primarily characterized by fresh-
water species which include: redbreast, sunfish, pumpkinseed sun-
fish, carp, large mouth bass , common sucker, eels, shiners , gold-
fish and minnows. The lower tidal portion of the Mamaroneck River
and Mamaroneck Harbor are characterized by estuarine species . (a
more complete listing of fish and wildlife resources is presented in
the Biology Appendix) .
2. 41. With regard to Mamaroneck Harbor the New York State Department
of Environmental Conservation and the U. S . National Marine Fisheries
Service have gathered information along the Westchester shore of Long
Island Sound and has been able to provide some insight into present
conditions . A fishery for striped bass, bluefish and blackfish
exists around the outer harbor, along with some recreational
catching of lobster. A small fishery exists within the Harbor
itself for snappers and bluefish. In August and September many
people can be found along the Harbor shore fishing for these species .
Eels , stickelback, toadfish, sculpin, killifish, flounder and
various rough fish are found on and near the harbor bottom, while
the shoal areas adjacent to the north side of Harbor Island Park
support some razor clams , soft shell clams and a few hard clams -
all inedible due to the poor quality of the bottom sediments . The
Harbor Master also reports some recreational fishing in the harbor
for flounder , smelt and snappers . The soft bottom sediments in the
mid channel areas support little in the way of shellfish. Progress-
ing outward from the harbor, more bottom life of all kinds can be
found, particularly away from the channel, in keeping with the im-
proved water quality of the open water areas . In the summertime,
large schools of juvenile mossbunkers can be found in the harbor .
Little or no spawning appears to take place in the harbor area with
the possible exceptions of killifish and silversides .
FISH AND WILDLIFE OF BYRAM RIVER STUDY AREA
2 . 42. Wildlife Habitat. The lands available fcr wildlife habitat
have been disturbed by the local developmental pressures that have
occurred within this region, but the Byram River can still be de-
30
scribed as presenting a relatively pleasant aesthetic character,
and does support numerous plant, fish and wildlife species . The
undeveloped lands within the immediate project region generally con-
sist of relatively natural wooded areas which line the stream
banks on both sides , and form the backyards of many of the local
residences . The largest undeveloped area is located along the west
bank of the River, upstream of Den Lane, where the local residencies
are generally situated at distances greater than 100 feet beyond
the stream. In addition the area' s close proximity to large regions
of undeveloped lands located above the project limits in Pemberwick
and Glenville provide additional resources for native wildlife .
2 . 43 . Vegetation. The types of vegetation found in the Byram River
project area is similar to those reported for the Mamaroneck-Shel-
drake project area. The area supports a mosaic of vegetation types
including wetland trees and shrubs. Trees such as black willows ,
black locust, alders , red-osier dogwood, black cherry, sycamore , maple,
ash line both banks . Vines and shrubs include poison ivy, honeysuckle ,
wild rose, spicebush, and maleberry. Also present in the area are
various native and domestic grasses .
2 . 44 . Wildlife. The native wildlife, although stressed by the area ' s
urban development, are similar to the types reported for the _'M:amaroneck-
Sheldrake Rivers Project, above. The area supports such mammals as
squirrels , chipmunks, mice, moles and shrews . The racoon is fairly
common and the longtail weasel and striped skunk may also, on occasion,
be seen in the area. Such woodland dwellers as the deermouse, muskrat,
and woodchuck may also utilize the area. The project area should also
support common turtles, snakes , lizards , toads and salamanders , al-
though these reptiles and amphibians are not readily seen. No threat-
ened or endangered species is known to inhabit the project area .
2 . 45 . Birds . Resident and migratory birds species common to the
Byram River project area and vicinity are similar to those gene-
rally reported, for the Mamaroneck-Sheldrake River project area
(paragraph 2 . 39 . It should be noted that a small group of water-
fowl, consisting mostly of mallards, has been observed to winter in
the vicinity of Pemberwick Lake. (paragraph 2. 39) . During a recent
Christmas count (National Audubon Society) some 107 different species
were observed in Greenwich, Connecticut. No threatened or endangered
species is known to inhabit the project area, although the American
peregrine falcon (U.S. endangered species) and the American osprey
(state endangered species) are rare coastal migrants and have been
observed within the Town of Greenwich.
2 . 46 . Fisheries Resources. Coordination with the Connecticut De-
partment of Environmental Protection and the U. S . Fish and Wild-
life Service has indicated that at one time some eighteen species of
fish have been collected in the Byram River basin; presently no sig-
nificant fishing is reported for the lower Byram River within the
project area, although common shiners , minnows , and eels may be found.
Above the upstream end of the project within Pemberwick Lake and
in the upstream reaches of the river, carp, bluegills , sunfish,
largemouth bass, eels , white suckers, and white perch are found .
31
RECREATIONAL FACILITIES
2 . 47 . General. Westchester County - Recreational facilities in
the County are bountiful, consisting of picnicking , golfing, swim-
ming, ice skating , fishing , boating, and nature study areas and
amusements, most of which are operated under the Westchester County
Department of Parks Recreation and Conservation. Blue Mountain Re-
servation near Peekskill, New York; Croton Point Park near Croton-
on-Hudson, New York, Saxon Woods Park near Mamaroneck and White
Plains , New York and Ward Pound Ridge Reservation near South Salem,
New York, provide over 7, 200 acres in or near the area for bathing,
hiking , picnicking, playground activities, skating , boating , riding,
ball-playing, overnight camping , nature study, and sleighing . In
addition, numerous other smaller parks and recreation areas supple-
ment these larger facilities . Playland at Rye, New York, is noted
for its prominence as an amusement area for adults and children.
This facility features rides, refreshment stands, a kiddy-land,
ice skating , a game room, and pier and boat-fishing. In addition,
numerous golf courses or country clubs are located near or within
the study area these include: Bonnie Briar and Winged Foot Country
Clubs and the Saxon Woods and Maple Moore golf courses .
2 . 48 . Mamaroneck-Sheldrake Study Areas . Existing facilities with-
in the unincorporated area of the Town of Mamaroneck includes some
86 acres of large parkland areas including the 25 acre Hammocks Area
Park and the 53 acre Sheldrake River (Nature) Trails . The village of
Mamaroneck also owns or operates numerous neighborhood or playground
parks and several larger parks which include the 10 acre Florence
Avenue Park and the 40 acre Harbor Island Park.
2 . 49 . The 1962 Village Master Plan noted a deficiency of 80 acres
in large parks; however , it also noted that the availability to
local residents of the near-by Saxon Woods County Park, the Hamp-
shire Country Club and the Mamaroneck Harbor facilities as being
supplementary to the overall needs for this category of recreational
facilities the 1966 Town of Mamaroneck Master Plan reports a total
deficiency of some 23 acres in Parkland areas for the unincorporated
areas (excluding the villages of Larchmont and Mamaroneck) based on
the estimated 1965 population. The plan recommends the preserva-
tion of the Bonnie Briar and Winged Foot Country Clubs along with
preservation of existing undeveloped areas in the southwestern sec-
tions of the Town, in order to alleviate these deficiencies .
2. 50. The Mamaroneck Harbor area also has excellent boating facilities `
and contains some six private boatyards , with a total slip capacity
exceeding 800 boats (a large number of land storage sites are also
available) , two boat sales and rental firms and four private boat
clubs with a substantial but undertermined capacity. Most boatyards
offer complete engine and hull repairs and two of the private yards
offer dockside sewage pumping service. The Village also provides a
boat launching ramp for residents . A number of the boat yards in
both the East and West Basins offer fuel and ice and therefore attract
substantial numbers of transient boats which enter the Harbor for
these services . In total, the Harbor Master estimates that approxi-
mately 1 , 400 boats have moorings or berths in the inner and outer
harbors .
32
2 . 51. Byram River Study Area . Numerous recreational facilities
can be found both within the Town of Greenwich and within the near-
by areas of Fairfield or Westchestcr Counties . The close proximity
of the Byram River project area to Long Island Sound provides out-
standing opportunities for residents in swimming , boating and fish-
ing activities . Recreational boating, for example, is quite popu-
lar in Port Chester Harbor and the adjacent water bodies . Several
marinas are located in the estuary of the Byram River and behind
North Manursing Island. Nine Connecticut State Parks are located
within Fairfield County among them Wooster Mountain Park and Putnam
Memorial Park providing additional recreational facilities to resi-
dents .
2 . 52. In addition to the regional recreational facilities avail-
able, the Town of Greenwich, maintains and operates several beaches
or waterfront parks which include Grass Island and Roger Sherman
Parks . In addition, the existence of several country clubs , the
town golf clubs , the Audubon trails , and Montgomery Pinetum all
tend to give the northern Greenwich area an open countryside char-
acter. There are no existing deficiencies reported for recrea-
tional acreage for this study area. A 1974 land use planning re-
port by the South Western Regional Planning Agency for Connecticut
recommends that an additional 560 acres of open space be set aside
in Greenwich by the year 1980 for such uses . Such acquisitions are
possible in view of the fact that about one-half of the Town ' s land
area is currently undeveloped.
TRANSPORTATION
2 . 53 . Mamaroneck, Sheldrake and Byram Rivers Basin. Adequate trans-
portation is available to and from the study areas as a result of the
continued expansion of services keeping pace with the regional popu-
lation growth. These facilities include the Westchester County Air-
port which is located approximately 4 miles northeast of White Plains
near the Connecticut border . It services all of Westchester County
including communities in surrounding areas . Intrastate and inter-
state rail passenger service is provided by Amtrak, the Penn-
Central Railroad and the New York, New Haven and Hartford Railroad.
2 . 54 . Numerous superhighways and first class highways provide good
vehicular transportation facilities. In the interstate category the
New York State Thruway (Interstate Route 87) extends along western
Westchester County linking New York City with Tarrytown, New York and
the intervening communities . The New England Thruway (Interstate
Route 95 paralleling the Connecticut shoreline of Long Island Sound
links northeastern New York City with points in eastern Connecticut
and Massachusetts. The Cross-Westchester Expressway (Interstate
Route 287) connects the New York State Thruway with the New England
Thruway in the vicinity of White Plains , New York. In addition,
other first class highways such as the Saw Mill River, the Bronx
River and the Hutchinson River Parkways provide service in a north-
south direction linking the Saw Mill River, the Bronx River, and the
Hutchinson Fiver Parkways and the New York State Thruway .
33
AIR QUALITY AND NOISE
2 . 55. Mamaroneck, Sheldrake, and Byram Rivers , Study Areas . The
study areas are located near one of the nation' s most densely popu-
lated and heavily industrialized center, the New York-New Jersey
Metropolitan Region. Pollutants such as sulfur dioxide and parti-
culate matter from these areas along with additional local emissions
from motor vehicles and buildings have resulted on occasions in po-
tentially dangerous air pollution concentrations for residents .
However, data obtained from air quality monitoring stations located
in Mamaroneck, Rye, Port Chester, New York and Greenwich, Connecti-
cut have generally reported ambient air quality levels within the
applicable state standards. Noise levels are also considered to
be at acceptable levels within the study areas .
AESTHETICS
2. 56 . Mamaroneck, Sheldrake Rivers Basin. Existing development
within the study area is varied and diversified. The upper
reaches of the Mamaroneck and Sheldrake Rivers are generally resi-
dential in nature. While the streams within this area have gene-
rally suffered from increasing development and encroachment along
their banks, there remain many areas which are aesthetically attrac-
tive and pleasant, still somewhat reminiscent of their undeveloped
state. The lower reaches located within the Village of Mamaroneck ,
include numerous private residencies as well as varied commercial
and light industrial establishments . Many of these establishments
have been constructed up to the edge of the channel banks . The
best use of this area aesthetically is not realized due to the hap-
hazard development and encroachment along the stream banks . Although
the Rivers within these areas contain stumps , branches , and garbage
debris, in general, they are devoid of obstacles . Of note, however ,
is one relatively scenic area located in the Upper Sheldrake River
area starting at about Briarcliff Road and ending at the small water-
falls just below Hickory Grove Drive, a distance of about 2 , 200 feet ,
the stream is lined with numerous large well-maintained trees and
combined with several rock outcroppings occurring along its banks
tends to create an unusually positive aesthetic appearance .
2. 57 . Byram River Basin. The Byram River study area does not have
any particularly outstanding aesthetic or scenic features which may
be noted here although as mentioned in paragraph 2 . 42 some natural
areas remain which are relatively attractive and pleasing in appear-
ance. In the lower project area, however , the residential and com-
mercial structures are located near the edge of the existing channel
barks thus leaving few natural areas remaining for this reach.
34
ARCHAEOLOGICAL & CULTURAL RESOURCES
2 . 58. Mamaroneck, Sheldrake, & Byram River Basins . There is no
known historical, cultural, or archaeological sites in the immediate
project areas listed in the National Register of Historic Places .
In addition, there are no known non-federally owned districts , sites ,
buildings, structures , objects of historic or cultural significance
that could be affected by the proposed works . Coordination with the
New York State Office of Historic Preservation indicates that there
presently are two sites listed in the National Register which are
located near the Mamaroneck-Sheldrake Project area. These sites
are: the Hyatt House in Scarsdale, and the Square House in Rye.
Coordination with the Connecticut State Historic Preservation Office
indicates that archaeological or aboriginal sites may be present in
Byram River project area although the area is considered disturbed
by the impacts of urbanization.
35
3 . RELATIONSHIP OF THE PROPOSED ACTION TO LAND
USE PLANS .
3 . 01. General. The various construction elements of the proposed
projects will, to some degree, influence the land use and develop-
ment of the study areas . Retaining walls , levees , floodwalls , pond-
ing areas and the miscellaneous interior drainage facilities all re-
quire land acquisitions which could not be used for otter purposes
once the elements are constructed, thus reducing the total number of
acres which could be developed for other uses . Construction activi-
ties would also result in some adverse impacts to transportational
and recreational facilities (see Sect. 4 of the REIS ) . However ,
implementation of the works would result in beneficial impacts of
providing design level flood protection to the lands within the
floodplain thereby reducing flood damages to homes and businesses .
The following paragraphs within this section will contain background
information and a discussion of probable significant effects to land
use and development, should the proposed plans be implemented.
EXISTING LAND USE AND ZONING
3. 02. Mamaroneck-Sheldrake Rivers Basin. In 1962, a comprehensive
land-use plan was prepared for the Village of Mamaroneck and in
1966, a master plan was prepared for the Town of Mamaroneck . These
plans, still in effect, closely adhere to the existing land use
patterns and are designed to perpetuate the character of the respec-
tive communities. The flood hazard areas within the Town of Mamar-
oneck and the Village of Mamaroneck are generally occupied by one-
family residential structures . The upper Mamaroneck River, in the
vicinity of First Street and upstream, is zoned as a low density
residential area. For the upper Sheldrake River, above Larchmont
Gardens Lake, the area is also zoned for low design residential and
consists exclusively of one-family homes . In the downstream vicinity ,
within the Village of Mamaroneck, these areas are zoned for medium
density housing and light industrial and commercial purposes . The
Mamaroneck Harbor area generally reflects mixed zoning . A portion
of the area bordering the East Basin is zoned for general commer-
cial use. The West Basin is zoned as general commercial and con-
tains one-family residential zones as well. No significant zoning
changes are predicted for the future.
3 . 03 . Byram River Basin. In 1963 , a land use plan of development
report was prepared for the Town of Greenwich. The plan closely ad-
hexes to existing land use and is in turn reflected in the zoning
regulations for the communities of Pemberwick and Greenville. The
upper project section, in the Pemberwick area of Greenwich, is
zoned for medium densities (2 to 12 familes per acre) and consists
mostly of one or two family detached dwellings . The lower project
area near West Putnam Avenue is zoned for business and medium resi-
dential density. Structures in this area consist mostly of light
industrial and commercial types along with several multi-residential
units .
36
FUTURE DEVELOPMENT, AND THE FLOOD PLAIN.
3 . 04. The New York State Legislature, in 1974 enacted Article 36
of the Envionmental Conservation Law. This law forms a flood plain
management program in the Department of Ervionmental Conservation
to provide technical assistance to communities for developing land
use regulations needed to participate in the National Flood Insur-
ance Programs of the Federal Insurance Administration. The Town
and Village of Mamaroneck are presently participating communities
in the Emergency Program of the NFIP. The Village of Port Chester
and the Town of Greenwich are also participating communities under
this program. under this insurance program, the referenced communi-
ties must adopt flood plain management regulations meeting the mini- j
mum standards of the Federal Insurance Administration. These stand-
ards include the requirement that all new construction in the identi-
fied area of special flood hazard be elevated or floodproofed to
the level of the base flood.
3 . 05. Both study areas are essentially fully developed; however,
the security against flooding provided by the flood control works
would encourage expansions and improvements to existing residences .
This would increase the future damage potential of the localities
involved (due to increased precipitation runoff and the loss of
natural flood storage) . In addition, increased community develop-
ment of the upstream flood plain areas would also tend to increase
this damage potential. Therefore, the extent and limits of the
flood channel and flood plain ought to be reviewed and revised to
provide for changing conditions as needed through appropriate zon-
ing legislation by the local governing body.
3. 06. The regulated management and use of the flood-plain is essen-
tially a responsibility of the local governmental agencies . The
Corps of Engineers is authorized to assist in the collection of data
necessary for the preparation of the appropriate regulatory legisla-
tion, if requested to do so by these agencies . It should be noted,
however, that should the proposed flood control project, be author-
ized for construction certain requirements would be necessary prior
to implementation. Prior to the initiation of construction, the
local governmental interests would be required to give satisfactory
assurance to the Secretary of the Army that they provide certain
assurances of local cooperating items, such as , construction cost
sharing , maintenance of facilities, etc. As part of this agree-
ment they would be required to do the following : (a) Prescribe
and enforce regulations to prevent encroachment on the flood storage
areas, channels, and rights-of-way as necessary for the proper func-
tioning of the project, and to provide a pumping station, or addi-
tional gravity outlets, due to the modification of , or encroachment
upon, such area by local interest; (b) Agree to adopt and enforce
adequate regulations to reduce flood damages along the referenced
streams within the localities involved, that will not be protected
by the recommended projects (refer to paragraph 1 . 19) . It should
also be noted, that under this pian, it would be required that the
diverted section of the lower Sheldrake River in the Village of
Mamaroneck be retained as a natural channel to carry local runoff .
37
3.07 Implementation of the Executive Order, Executive Order 11988,
released May 24, 1977, revokes and replaces Executive Order 11296,
issued August 10, 1966. The new Order, entitled "Floodplain Manage-
ment," sets forth a new general policy and cites specific requirements
for compliance by all Federal executive agencies. Executive Order
11988 required agencies to avoid to the extent possible the long
and short tern, adverse impacts associated with the occupancy and
modification of floodplains and to avoid the direct or indirect support
of floodplain development whenever there is a practicable alternative.
The preferred method for satisfying this requirement is to avoid flood-
plain sites. However, the proposed flood control projects for the
Mamaroneck - Sheldrake Rivers Basin and the Byram River Basin are
located within urbanized areas which have high flood hazard potentials.
A "No action" plan or the avoidance of flood protection works within
the floodplain is not considered a practical alternative since these
alternatives would allow flood damages to continue (refer to Section
6 of the REIS for the other alternative actions to the proposed action
considered) . Floodplain regulations, as stated in paragraphs 1.19
and 3.06, would be required within the localities involved under the
items of local cooperation.
3.08. Land Acquisitions and Spoil Disposal . As shown on Table 2 ,
the construction of the proposed flood control plans would require
that certain lands within the flood plain be acquired as permanent
or temporary easements . For the Mamaroneck and Sheldrake Rivers
approximately 31 acres of land would be required as permanent ease-
ments . For the Byram River one residential structure would be
acquired, and approximately 21 acres of permanent easements are needed
of which 10 acres are for the existing Pemberwick Lake. These lands
could not be used for any other purpose throughout the life of the
project. Those individuals whose lands are acquired could suffer eco-
nomic loss , however, their remaining property would not be subjected
to flood damages and therefore would be enhanced. Temporary easements
of 15 acres and about 3 acres would be required for each project,
respectively. These easements are necessary to accommodate con-
struction equipment and materials such as storage and staging areas
during construction activities . Suitable dredged material from the
proposed channel excavations would be used in the levee construc-
tion and for the fill areas . Construction procedures will include
salvaging and reuse of the removed topsoil material . All excavated
material stored at the proposed project areas would be stabilized and
protected from erosion. If excess dredged material is generated
this would be deposited at approved upland sites after coordination
with the appropriate regulatory agencies. One potential disposal
site is the Terra Cone property located in Port Chester, New York .
At this stage in the study insufficient information is presently available
concerning the numbers and locations of disposal sites that would be needed.
At the later planning stages of this flood control study, all of the evaluation
factors for the selection of disposal sites for the dredged material will be
considered in accordance with 40 CFR 230.3-230.5 and 33 CFR 209.145 (under
Section 404, Public Law 92-300, Water Pollution Control Act Amendments of 1972) .
38
ENVIRONME.vTAL I.dPACT OF THE PROPOSED ACTION
Mamaroneck and Sheldrake and Byram River Basins
4 . 01. General. The results of this study and earlier preliminary
studies for the project areas indicate that the flood control pro-
jects will produce benefits by reducing flood damages and business
losses . These benefits, which can be quantified monetarily, must
be weighed against the social and environmental costs of the project
which are, for the most part, intangible.
4. 02. Implementation of the proposed structural plans is expected
to cause certain temporary and permanent environmental effects . Air
quality, noise levels and the appearance of the area would be ad-
versely impacted by the construction activities . Movement of trucks
with construction material through streets , and equipment operation
would generate noise and contribute to air pollution by windblown
dirt and gas emissions . There would be some interference with nor-
mal traffic conditions . However, all of these impacts would be
temporary, lasting only during construction. Channel excavation to
widen and deepen the Rivers would create temporary turbidity which
could adversely affect water quality downstream. Additional ad-
verse impacts would occur due to a reduction of wildlife habitat
areas and its aesthetic features . Most construction scars would
begin to heal in a year or two as regrowth takes place. The main
beneficial effect of plan implementation would be the alleviation
of the flood hazards for floods up to the design levels of protection.
4. 03 . The impacts of the proposed project on specific features
and resources in the study areas are discussed in greater detail
below. Information concerning land use impacts is contained in Sec-
tion 3 of this report. Information concerning alternatives to the
recommended plans and the impacts of these alternatives is given in
Section 6 of this statement.
4 . 04 . Aesthetics . One of the more permanent and noticeable effects ,
but also one that is based on subjective factors , is the probable
adverse impacts of project implementation to aesthetics . The re-
moval of natural vegetation for levee or retaining wall construc-
tion or channel excavations would diminish the natural beauty of
the presently less developed areas within the study areas involved.
Where channel modification are also proposed, the presence of wider
deeper channels may present negative appearances due to the pre-
sence of the unnatural or man-made works . For the Byram River pro-
ject the high levees or floodwalls for example, may present an ob-
stacle to those who wish access to the River or view their immediate
surroundings. Construction activities would mar the project areas
with the presence of construction equipment and the general dis-
array usually accompanying construction activities . Upon comple-
tion_ of the project, a beautification and tree planting program
will be initiated as a measure to mitigate these effects . As men-
tioned in paragraphs 2. 56 and 2. 57 there is a relatively scenic area
located in the Upper Sheldrake area below Landsdowne Drive. This
scenic area, however would be preserved since flood control works
would no longer be provided for this area of the Sheldrake River
(Refer to Paragraph 9. 03) .
39
4 . 05. Geology and Soils . The proposed projects would not affect major
topographic features in the areas . Construction activities , particu-
larly levee construction, channel excavations , clearing and grubbing
of vegetation would cause some erosion and turbidity problems . As
indicated in Paragraphs 2. 26 and 2. 27 subsurface explorations have
revealed that the type of materials present in the study area is
variable. Generally, the lower strata, particularly in the
Marmaroneck-Sheldrake Rivers Basin, consists of gravelly material
(with bedrock being encountered at several of the drill holes) .
These types of materials have relatively low erodability values .
The upper strata material encountered in some locations , however,
consisted of fine sands , silts or topsoils . These types of materials
are considerably more susceptible to erosion than coarser materials .
Based in part on coordination with the United States Soils Conser-
vation Service, mitigation measures will be implemented during con-
struction activities which should significantly minimize these
effects . No prime or unique farmlands would be impacted by the
proposed works .
4. 06 . Sedimentation. The question of sedimentation is , of course ,
related to the geology of the basins as well as the stream character-
istics . However, certain generalities can be stated about the
changes in sedimentation induced by channel modifications . When a
channel is straightened, this tends to increase the slope, usually
in intermediate and often isolated stretches but not overall in the
area. This increased slope in certain sections implies a change in
the stream' s capacity for carrying sediments if the width remains
constant. However, channel modification usually involves a change ,
generally an increase, in the width of the channel and an increased
slope together with an increased width implies a decrease in depth.
This in turn means that the bottom velocity will increase and, there-
fore, scour will occur. If the channel bottom is designed so that
scour does occur, this would imply that at some critical velocity
downstream, siltation will occur and this siltation will slowly ex-
tend backup the stream from the downstream reach. Such a siltation
problem would make it mandatory that maintenance be carried out on
a regular basis . A stream channel in its natural state seeks to
achieve a minimum expenditure of energy but a newly modified channel
cannot adjust rapidly to a change in sediment load and changes in
both depth and velocity can occur.
4. 07 . Water Resources . The most obvious beneficial aspect of the
proposed project is the flood protection to be derived from control
of the stream. The construction efforts necessary to achieve this
goal will involve some adverse effects such as turbidity and slight
erosion problems but the stream will clear and begin to adjust to
a new set of conditions after construction ends . Construction tech-
niques commonly employed in this kind of project, such as diversion
channels , silt screens , and temporary ponding areas , can serve to
minimize the impacts while the project is being built. Sources of
the public ' s water supply would not be affected by implementation
of the proposed projects .
40
4. O8 . Since the projects are designed for the specific purpose of
flood control, it may not offer any benefits such as water supply ,
navigation or recreation, nor is it specifically intended to im-
prove water quality. The complete project may result in changes
such as reduced oxygen levels , elevated water temperatures and
changes in sedimentation.
4 . 09 . Water Quality. Most of the adverse impacts on water quality
will occur during and immediately following construction. The most
noticeable effect will be the increased turbidity caused by clear-
ing and excavation. Construction measures will include revegetating
and stabilizing the denuded channel banks to prevent continued erosion.
The possibility of accidental pollution from debris or construction
materials exists although careful supervision can help to forestall
this potential problem. If changes in channel slope result from
project construction, scour and siltaticn may be a continuing problem.
Other possible effects may be elevated temperatures , reduced photo-
synthetic activity and reduced dissolved oxygen levels .
4. 10. Maintenance. Periodic channel maintenance following comple-
tion of a flood control project may present problems . At this point,
the depth of study is not sufficient to indicate the details of
maintenance which might be required. However, if bankside vegeta-
tion should require removal, the application of herbicides will be
avoided. According to the Repot On Channel :Modification prepared for
the Council on Environmental Quality by A. D. Little Inc . , the recovery
of a stream from channel modification seems to be largely determined
by the degree and amount of channel maintenance required . If the bed
of the stream is allowed to stabilize and plant growth is allowed to
develop upon the berms , stable habitats can form and aquatic life forms
can reestablish themselves within the stream channel . The vegetation
along the banks also contributes to recovery. Continual maintenance
could have almost as severe effects as actual construction as far as
aquatic and amphibious life forms and vegetation are concerned .
4 . 11. Air Quality. Construction of the proposed facilities will
have a minor short-term effect on air quality . Exhaust fumes from
mechanical equipment and on site power generators will cause local
increases of certain fossil fuel constituents . Dust from blasting,
digging or disturbance of exposed soil may be a local nuisance .
While exhaust fumes may be difficult to reduce substantially , every
attempt will be made to utilize existing electric power reducing
the need for on-site generators . Dust generation may be controlled
by sweeping dirt off pavement, watering access roads or using cal-
cium chloride in such exposed areas . The use of wetting agents or
detergents can reduce dust from rock drilling or blasting . Further-
more, the disposal of waste material through open burning should be
prohibited.
4 . 12 . Noise. Project construction operations would produce in-
creased levels of noise throucThout the course of construction.
Local, State and Federal regulations would be adhered to in all
cases but it must be recognized that these noises cannot be totally
eliminated and will still be at a level of adverse impact . The
greatest impact would be where the project area is in close proxi-
mity to a residential area.
!+1
SOCIAL EFFECTS - MAMARONECK-SHELDRAKE AND BYRAM STUDY AREAS .
4 . 13 . Community Cohesion. There would be a very minimal adverse
affect on community cohesion because of these projects . Of the
several hundred 'homes in the present flood plains , none would be re-
moved in the Mamaroneck and Sheldrake flood plain and 1 in the
Byram flood plain because of the respective projects . Minimal land
will be taken from Columbus Park at the confluence of Mamaroneck
and Sheldrake Rivers and losses would result from channel excava-
tions and the building of the various other structural works as de-
scribed in Section 1.
4 . 14. Employment Effects. There will be no adverse employment ef-
fects as a result of the project, since no industrial or commercial
structures would be removed or reduced in size. Since several of
the industrial and commercial establishments at the Mamaroneck and
Sheldrake Rivers study area have suffered flood damages in the past,
the effects of this project would be beneficial. There would also
be direct benefits to employment during the construction of each pro-
ject. It is considered that the construction labor forces would be
drawn from the immediate surrounding regions , with normal work-
commuting distances up to 50 miles .
4 . 15 . Taxes and Property Values . Some private lands are to be ac-
quired for the project. The loss in tax revenue should be more than
offset by the resulting land enhancement after the area is protected
from flooding.
4 . 16 . Displacement of People, Businesses and Farms . As previously
mentioned one home would be removed because of the projects , and there
would be no displacement of businesses or other commercial enter-
prises . There are no farms in the area.
4 . 17. community and Regional Growth. These flood control projects
should not disrupt desirable community and regional growth.
4 . 18 . Institutional Impacts . The costs of maintenance of the
project works , for which the local villages or towns will be
responsible, will place a financial burden on the communities affected
and the removal of taxable lands may also reduce local revenues . How-
ever, these costs are expected to be negligible when considered in
the context of the entire project (refer to Table 1) .
VEGETATION, FISH AND WILDLIFE RESOURCES
4 . 19 . General. When considering the effects of the projects on
the ecosystems, all the impacts on vegetation and the aquatic and
terrestrial life forms are interrelated. Although as described in
Section 2, the resources present are marginal, certain effects to
existing resources would still occur, and in certain cases , these
effects could be of a lasting or permanent nature. Increases in
turbidity and siltation levels result from construction and damage
aquatic life by clogging the breathing mec'nanisms of invertebrates
and filling pools and crevices which are their favored habitats .
42
This will adversely affect the organisms and may entirely eliminate
populations . The silt will probably wash out in one or two years
and reropulations will be possible. However, the loss of aquatic
flora and fauna and bankside vegetation will limit the ability of
the fish to return once construction is complete with the result
that the diminished food sources would limit the population espe-
cially during the first year or so. In addition, temperature
changes may affect the species diversity unless properly designed
low flow channels are included in the projects .
4. 20. The currents , pools and rifles in a stream are also im-
portant ecological factors in maintaining stream life . Project
related changes in these factors also affect species diversity and -
can induce conditions such as elevated temperatures and reduced
oxygen levels. Removing bankside vegetation can also bring about
elevated water temperatures by removing shade and variations in
light intensities and can eliminate some of the food sources for
aquatic and amphibious life forms . In addition, losses in trees ,
bushes and other vegetation along the streams would remove the
habitat and feeding areas for birds and small mammals . Trees ,
leaves , and insects that live or feed on leaves fall into streams
and provide a base for the food web. Also, the streamside vegeta-
tion is composed of many different species of trees and other plants
so that a variety of types of detritus enter the stream. Besides
the obvious effects of clearing of streamside vegetation, the pro-
ject may sharply reduce the variety of food sources since replant-
ing usually involves only a limited number of species . The changed
conditions along the streams may not support the same shrubs and
trees as presently are found and the change in vegetative species
diversity can affect the populations of birds and mammals which
choose to return to the site. Burrowing animals such as muskrats
whose den entrances may be submerged along the stream banks and
amphibians such as frogs whose life cycles are intimately tied to
the water as well as land would be directly affected by construction
activities .
4. 21 . Adverse impacts to fishers resources would be expected to
occur due to the proposed channel modifications . The aquatic habitat
along the entire length of the modified channels would be disturbed .
Breeding and spawning of fish could be inhibited if construction occurs
during spawning seasons . The importance of the river areas to be modi-
fied as fish spawning areas is presently not known, however , coordi-
nation with the appropriate State and Federal agencies would continue .
As described in paragraphs 2 . 40 and 2. 46 , however, the primary fishery
resources are generally present in the lakes of the respective
river basins. Of the fish species reported only minnows and
shiners were observed during site visits in the spring and fall by
Corps of Engineer personnel within the immediate channel areas of
the proposed works . For the Byram River no species were observed,
although these specie: are common and may also be present there . One
potential adverse eff=ct would be the diminished potential of restor-
ing the existing streambank areas to higher quality fish and wildlife
43
habitats, once the proposed channel alterations are implemented. For
the lower Sheldrake and Mamaroneck Rivers area about 8, 200 feet of
existing channels would be widened and deepened, and approximately
3, 000 feet would be modified along the upper Mamaroneck River.
Approximately 2, 500 feet of existing channels would be modified
along the upper Sheldrake River. For the Byram River, about 2, 000
feet of existing channels would be altered.
4 . 22 . Mamaroneck-Sheldrake Rivers Basin. As mentioned previously,
in paragraph 2.36a the wildlife resources within the proposed
pro-ject area are diminished. Construction of retaining walls , levees ,
channel excavations and placement of fill would, however, adversely
impact wildlife resources . The narrow strips of relatively undeve-
loped lands present along the streambanks , consisting of trees and
underbrush would be removed as a direct result of the construction
activities . The greatest adverse impact would be to the area along
the Mamaroneck River upstream of Jefferson Avenue to the vicinity
of New England Thruway and upstream of Lawrence Street to the
vicinity of Warren Avenue, where more resources are available.
Approximately 12 acres of vegetation and wildlife habitat would be
eliminated or severely effected by the construction activities . It
should be noted that the designated fill placement areas indicated
on Figure 3, in general, consists of developed land areas . In
addition, in those fill areas where vegetation would be impacted,
the depths of fill required would vary from 6 inches to 3 feet, as
needed in order to eliminate low-lying areas adjacent to the streams .
These disturbed areas could easily be revegetated upon project com-
pletion. The cumulative effect of removing the above-mentioned
habitat acreage would be expected to decrease or eliminate wildlife
populations now present in the immediate project area, however,
numerous other habitat areas are present within region and which
support the types of wildlife forms found in the project area. In
addition, there are no known threatened or endangered species present
in the project reaches which would be adversely effected.
4. 23 . Byram River Bain. As described in paragraph 2. 42 , the wild-
life resources within the Byram River project area are also dimi-
nished. The largest adverse impact would occur to the upstream pro-
ject reach where the resources present would be effected by the
levee construction and channel excavations . Some adjacent stream
vegetation would also be removed due to the floodwall construction
within the downstream project limit. A total of about 3 acres of
vegetation and wildlife habitat would be eliminated by the construc-
tion works . Fill material would be placed in the designated areas
behind the proposed floodwall as indicated in Figure 6 . The
cumulative effects of removing this relatively natural habitat
acreage would also be expected to decrease or eliminate existing
wildlife populations from the immediate project area, however, no
known threatened or endangered wildlife species would be adversely
effected by the proposed works . Numerous other undeveloped lands
and habitat areas near the project area support the kinds of wild-
life forms found within the project area.
44
MAMARONECK AND SHELDRAKE RIVER BASIN
4 . 24. Impacts Associated with the Fenimore Road Diversion Tunnel.
As indicated in Section 2 of this Environmental Statement, the
Mamaroneck-Sheldrake Rivers Basin is located in an urban area and
that the waterways in question may generally be considered as
polluted (refer to Paragraphs 2. 31-2. 33) . A review of the bottom
samples taken from the Mamaroneck Harbor area tends to support this
statement for the Harbor area as well. The proposed inclusion of
the Fenimore Road diversion will, under normal conditions , result
in only a 17 cubic feet per second of flow being discharged into the
West Basin of the Harbor. Under future conditions , the water quality
within the Harbor area may be expected to improve, particularly with
the proposed upgrading of the Mamaroneck Sewage Treatment Plant
located on Harbor Island; however , the urban character of the area
is projected to continue. As a result of this , the primary sources
of water pollution, that is , municipal and industrial wastes , com-
bined sewer overflows , non-point sources , wastes from boating activi-
ties including pleasure and commercial craft, oil spills , and thermal
inputs , etc. would be expected to continue. Accordingly, the long-term
effects of this tunnel scheme should be of minimal importance. The following
paragraphs contain additional information concerning other potential proiect im-
pacts to water quality within the study areas.
4 . 25. Construction of the projects would cause the modified charnels
to contain the water flow during periods of heavy rains or flooding.
For the Mamaroneck Project, inclusion of a tunnel diversion scheme
would result in the flow from the lower Sheldrake being diverted
into the West Basin. In order to understand what potential impacts
to water quality would result, it may be helpful to describe the
present treatment for storm water waste flow (refer also to para-
graph 2 . 31) . Municipal and industrial waste from the area receive
treatment from the Mamaroneck Wastewater Treatment Plant located on
West Boston Post Road in the Village of Mamaroneck (near Mamaroneck
Harbor) . The system provides only primary treatment for an average
flow of 18. 5 MGD, with a plant design capacity of only 18 MGD. The
collection system is only partially combined sewers , since many
sewers discharge directly into the waterways , the principal dis-
charge is to the Long Island Sound at the center of a 1 square mile
section of SB waters . A plant bypass for wet weather flows dis-
charges directly into SB waters of the East Basin of the Harbor .
Another plant bypass discharges into the SB waters of the west Basin. .
The inclusion of the diversion tunnel with the outfall into the
West Basin would therefore not be a significant change over this
existing scenario. Although the abandoned lower Sheldake River
would lose its base flow, the existing channels would serve to
carry local runoff. . Some stagnation pools could develop, if flows
are not sufficient enough to cause periodic flushing (mitigation
measures such as the proper grading and maintenance of the lower
channel areas should minimize this effect) . Also, poor drainage
in the stream following rainstorms or the formation of residual-
stagnated
esidualstagnated pools can act as a suitable breeding ground for
45
mosquitos which could pose as a potential health hazard. Dredging
activities for channel modifications upstream would be expected
to increase turbidity and sedimentation levels at the downstream
areas. The discoloration of the water may also occur .
4. 26 . Construction of the diversion system would also require that
approximately 1, 500 cubic yards of material would be dredged from
the West Basin. The type of dredge that would be used has not yet
been determined, however, it is probable that either a clamshell or
a bucket dredge would be utilized for such proposed work. The limits
of the dredging required are not anticipated to go beyond the U. S .
Pier and Bulkhead Line, located about 100 feet offshore. The effects
of construction to the mooring of pleasure boats within the basin area
are not expected to be significant. Coordination on the potential
effects , however, with regard to navigation would be effected with
the L. S. Coast Guard.
4 . 27. Dredging Impacts . The interaction with estuaries are very com-
plex, and involve many factors . Presently, the impacts of dredging
are primarily identified with short term impacts in several areas .
(a) . The most obvious impact is the removal of benthic organisms in
the dredged material. Although this process may result in a kill
of organisms, the impact does not appear significant for localized
dredging operations. While decreases in populations do occur, the
repopulation rate is fairly rapid.
(b) . The ability of animals to withstand the adverse effects of burial in
areas near the dredge site depends on their behavior and morphology.
Species such as large polychaetes and bivalves which can burrow have
been shown to survive burial of up to 21 cm sediments . However, attach-
ed sessile species are probably killed by burial of any magnitude. As
with the prior case of removal, recovery rates are fairly rapid . It
also has been hypothesized that activities related to dredging such
as increased marine traffic also disturb the benthic deposits for fre-
quent short periods . Thus, acute biological impacts due to actual
dredging may not be significant even though large quantities of sedi-
ments are removed because the benthic organisms have adjusted to a
state of continuous physical overturn.
(c) . The most commonly reported effect of dredging on water quality is
an increase in turbidity and suspended solids . This impact is usually
minor. This assumption is based on two points. First, the increases
in turbidity and suspended solids occurs in localized areas which
pelagic species can probably avoid. Second, periodic high turbidity
levels are part of the evolutionary experience of estuaries . Sediments
are resuspended by wind, waves and tidal scour and large sediment loads
are carried with the winter fresh water flows. A 20-fold increase in
suspended sediment concentrations in Chesapeake Bay has resulted from
natural occurrences. With this evolutionary experience, many estuar-
ine animals are tolerant to waters carrying suspended solids . Tests
with fish and lobsters held in waters with several grams/liter of sus-
pended sediments showed no significant mortalities . Thus , turbidity-
related impacts do not seem to be significant in most cases .
46
(d) . Dredging of sediments will result in the release or organic mat-
erials and inorganic materials (such as sulfides) that can create an
oxygen demand in the project waters . under certain, conditions , sig-
nificant reductions of dissolved oxygen concentrations can result dur-
ing dredging operations . In addition, dredging operations may expose
benthic deposits of high oxygen demand that had been previously covered
with relatively clean materials. Organic material resuspended by
dredging operations may settle on the benthic surface and increase
the benthic oxygen demand. The reverse can also be true, as is the
case, if dredging operations lead to the removal of polluted sediments .
(e) . Benthic communities may became modified in an estuary which has '
repeated dredging into a relatively resistant community. This com-
munity may have become adapted to a more or less continual resuspen-
sion of the sediments and its persistence may actually depend on this
turnover. The turnover may depend more upon the prop wash of large
ships than on the continual maintenance dredging. Irregardless , the
biological community will exhibit characteristics commonly attributed
to communities in polluted environments and will not be significantly
altered by dredging.
(f) . The release of heavy metals from polluted sediments and its
effect on the water column is still uncertain. Heavy metals absorb
both Fe (III) oxides and Fe (II ) sulfides . In addition, the heavy
metals are readily co-precipitated and incorporated within sulfide
bearing sediments indicating the non-release of these metals into
the water column as result of dredging . Important hydrocarbons in
relation to the toxicity of dredge material include insecticides
and polychlorinated biphenyls. The possible adverse effect of
dredged material contaminated with these compounds are numerous;
however, direct cause-and-effect relationships are virtually non-
existent.
(g) . Finally, in light of legislation requiring the upgrading of
effluent discharges , both sanitary and industrial, the removal of
polluted bottom material will be a long term direct benefit to the
project area.
RECREATIONAL FACILITIES
4 . 28 . Mamaroneck and Sheldrake River Basins . The structural ele-
ments for the proposed Mamaroneck and Sheldrake Rivers project
(such as channel modifications, flume, levee and floodwall construc-
tion, etc. ) would not significantly affect recreational facilities
in the area, although a reduction in usuable open space would result.
The streams do not have any recreational use except for some limited
recreational fishing confined mostly to lakes occurring in the river
basins . Two existing recreational facilities located in the Village
of Mamaroneck would be slightly reduced in size because of the re-
quired land easements. In Columbus Park, for example, the construc-
tion of the wider channels would require a strip of land about 20
feet wide along streambanks within the park. The other affected
facility is a playground and park area located just below warren
Avenue. In this reach the lands required for channel modifications
and the construction of the small embankment or levee would remove
47
a 20 to 30 foot wide strip of land along the right river bank .
Access to the streams or use of these areas would not be prevented
with the construction of these works. It should be pointed out that
lands required as easements are essentially open space riverbank
areas which have recreational potential if developed into park areas .
Implementation of the construction works would result in a loss of
this potential in exchange for protection of the remaining developed
and undeveloped lands within the flood area.
4 . 29 . Byram River Basin. The proposed flood control works for the
Byram River would not have any adverse effect to any existing park
or recreational facility. Sports fishing within the project area
is not reported due to the present degraded water quality of the
lower Byram River. A significant fishery resource is reported for
areas in the river basin upstream of the project, however, these
areas would not be effected. In addition, the proposed Byram River
Gorge Park, in the Town of Greenwich, located several miles upstream
would not be adversely impacted.
TRANSPORTATION
4 . 30. Mamaroneck and Sheldrake Rivers Basin. In general construction
activities would cause minor interruptions of traffic flows due to the
shipment of construction materials and the removal of debris , as well
as inconveniences to the public due to the presence of heavy equip-
ment. The diversion tunnel scheme for the Sheldrake River would re-
quire the partial closing of Fenimore Road. These works would have
the effect of interrupting traffic flow along these routes . In addi-
tion, where bridge replacement or alterations are required additional
temporary adverse effects would be associated with these construction
activities .
4. 31. Bridge Work. As indicated in Section 1 of the EIS , several
bridges which span the Mamaroneck and Sheldrake Rivers would be
altered or replaced. These bridges include highway bridges , several
footbridges , a utility bridge, and a railroad bridge. The impacts
associated with these alternatives would be temporary related mostly
to traffic interruption. More significant adverse impacts are anti-
cipated in the Mamaroneck Village area where the bridges affected
by the various structural plans include the Ward Avenue, Valley Place,
Halstead Avenue, Station Plaza, Jefferson Avenue, Hillside Avenue,
First Street and Fenimore Road Bridges , and in the Town of Mamaroneck
area Fernwood Road and Hickory Grove Drive Bridges would be affected.
These adverse effects would be mitigated through the use of signal
devices , scheduling of work, and rerouting of traffic. Coordination
with local interests in locating alternate routes to service the
areas affected by the alterations to the bridges would be developed
and effected.
4. 32. Fenimore goad and Diversion Tunnel. Fenimore Road is one of
the key north-south routes for local traffic within the boundaries of
the Village of Mamaroneck. Alternate north-south routes in the area
include Rockland Avenue and Weaver Street (Route 125) to the west and
Old White Plains Road (Mamaroneck Avenue) to the east of the proposed
tunnel route at Fenimore Road. The proposed tunnel construction would
require more than two years to complete. During the construction per-
iod adverse impacts to traffic flows such as traffic delays and de-
48
tours at closed sections of the road may be anticipated. The more
significant effects would occur to the Village' s North Fenimore Road
area where the area has primarily been developed as an industrial-
commercial zone. The east-west routes in this area are narrow roads
which would have minimal capacities to handle additional traffic
flows by-passing the construction area. Every effort would be made
to minimize these adverse effects with the use of such mitigation
measures as performing tunnel work on a section by section basis .
During the later planning stages , additional coordination would be
effected with local agencies in order to further identify other miti-
gation measures .
4 . 33. Mamaroneck Station Parking Areas . The recommended plan which
includes the Fenimore Road diversion tunnel, would require a recti-
fication of the Mamaroneck River channel between Jefferson Avenue
and the New Haven Railroad. This would entail the construction of
several hundred feet of new channel filling of that part of the
existing channel which the new channel would replace. The easements
for the new channel would include approximately 75 percent of the
average of the existing parking lot on the southwest corner of
Jefferson Avenue and Station Plaza, the loss of which would create
hardship to commuters using the New Haven Railroad at the Village
Station. Such adverse effects would be temporary, however, because
the vacated channel would be filled and graded to provide two park-
ing lots approximately equal to the total existing acreage lost.
These new areas would then be used as parking areas at Station Plaza.
The duration of construction activities at the commuter parking
facitity and Station Plaza is estimated at one year.
4 . 34. Byram River Basin. For this project area, the adverse im-
pacts due to the construction activities would be similar to that
described in paragraph 4. 30 for the Mamaroneck-Sheldrake study area.
The movement of trucks or the operation of equipment, for example ,
would cause temporary interruptions to local traffic. The installa-
tion of the storm interceptors for Rex Street and for Lucy Street
would result in the partial closing of these roads to traffic. The
proposed flood control project for the Byram River would not, how-
ever, require the replacement of any bridges . These adverse effects
may be mitigated by the scheduling of material delivery and other
trucking activities during off hour traffic periods . The duration
of construction at this study area is estimated at two years .
ARCHAEOLOGICAL AND CULTURAL RESOURCES
4. 35 . General. In January 1977 , a cultural resources survey was
prepared for the New York District Corps of Engineers by archaelogi-
cal consultants regarding the proposed project areas for the
Mamaroneck, Sheldrake, and Byram Rivers. On the basis of this study,
no cultural resources eligible for inclusion in the National Register
of Historic Places were found within any of the affected areas . Some
buildings or sites with potential cultural or historial interest were
discovered. These areas will be discussed in the following para-
graphs . The detailed cultural resources report was circulated by
this office for review and comments tc the appropriate State and
Federal Agencies. Copies of the letters of coordination are at-
tached in Appendix D of this statement.
49
4. 36 . Mamaroneck and Sheldrake Rivers . The results of the cultural
resources survey indicate that for this area there are no cultural
resources present which would be negatively affected by the pro-
posed construction works. Two existing structures of historic in-
terest were found, within the Village of Mamaroneck, New York, in
the project area limits . These structures are the "Delancy House"
(1792) , now a partially renovated restaurant, (which was moved to
its present location) located just off Fenimore Road on Boston Post
Road and the "Mamaroneck Water Works No. 1 Building and Pump House
(pre-1900) located just upstream of the Winfield Avenue bridge. The
Delancy House is presently a Town of Mamaroneck Landmark. The re-
port recommends that appropriate safety precautions be taken should
excavations or blasting be required in these areas , so that, these
structures would not be disturbed. In addition, it was recommended
that the New York State Historic Preservation Office be contacted
should cultural artifacts be found during construction activities
along the upper Mamaroneck River area, where potential resources
may be present.
4. 37 . Byram River. For the Byram River project area no eligible
resources were discovered, as mentioned previously. One midden or
garbage dump, however, was located within the project limits which
yielded artifacts of recent origin. Although this resource was not
considered significant, during construction coordination will be
effected with the Connecticut Historic Preservation Office should
additional artifacts be discovered.
MITIGATION MEASURES
4 . 38 . General. While some of the adverse impacts on fish and wild-
life resources, aesthetics and vegetation are unavoidable, there are
methods by which the impacts can be mitigated somewhat. The pro-
vision for a more extensive replant procedure than is normally fol-
lowed would help to restore the area to an aesthetically acceptable
appearance and provide attractive resting and nesting places for re-
turning birds and animals to the extent possible. Indigenous spe-
cies of vegetation should be planted with interspersals of fast-
growing plants to stabilize the levee banks and provide quick cover
for remaining or returning wildlife. The construction should be
carefully planned and activities should be confined to the immediate
project sites as strictly as possible to prevent unnecessary destruc-
tion. Along the stream banks , there are some stands of trees and
other vegetation which would be preserved to provide stability,
screens from construction and refuge areas for wildlife as well as
for their innate and aesthetic value.
4 . 39. Coordination with the U. S . Fish and Wildlife Service would
continue throughout the development of plans and specifications in
order to seek ways to avoid destruction of the fish present in the
streams and to include areas in the new channel such as properly
placed pilot channels, resting places , riffles or pools which would
provide suitable habitat for fish and other aquatic life after com-
pletion of the project. Some value will be gained from the refuge
that may be offered to wildlife within the undeveloped parkland
areas located near both project areas .
50
4 . 40. In general the projects call for a pool and riffle low flow
channel within the main channel which is relatively narrow and deep
so that the fishery resource value of the streams can be salvaged.
Besides careful choice of size and depth, the design would allow
for a meandering pilot channel which can take advantage of natural
shade or cover. Small log or rock dams and variation in the rough-
ness of the bottom in the channel will make the streams attractive
habitat for returning fish and encourage the establishment of a
variety of aquatic flora and fauna. Oxbows and meanders are charac-
teristics of the natural tendency of channels to seek sinuous paths
and their loss in the newly modified streams can be partly offset by
construction of alternating pool and riffle areas (see Paragraphs
1 . 20 and 1. 21) .
4.41 Wetland Resources. Wetlands have been declared on important national
resource warranting specific measures for their preservation by the President
in Executive Order 11990, dated May 24, 1977. Wetlands are generally defined
as those areas which are inundated or saturated by surface or ground water
at a frequency and duration sufficient to support, and that under normal
circumstances do support, a prevalence of vegetation typically adapted for
life in saturated soil conditions. Wetlands generally include swamps, marshes,
bogs and similar areas. As indicated in Section 2 of this environmental
statement the project areas are generally urbanized in nature, containing few
natural resources. Although willow trees and sycamores and other wetland
vegetation may be found along the streambanks in a few places, nowhere along
the project area are there significant concentrations of wetland vegetation.
The species noted were invariably mixed with other species not associated
with a wetland environment. Project impacts on wetlands areas, therefore,
is expected to be minimal.
51
S. ANY PROBABLY ADVERSE EFFECTS WHICH CANNOT BE AVOIDED
5 . 01. While many of the potentially adverse effects can be miti-
gated, if not prevented, it would be unrealistic to suppose that no
adverse effects will occur. The most immediate and obvious effects
are those associated with construction such as increases in noise
and air pollution resulting from construction-machinery and activi-
ties along with the increases in turbidity and siltation in the
streams both during and for some time following project construction.
If the new channels are properly designed, the streams will grad-
ually readjust so that siltation should not be a continuing problem.
However, the increased turbidity and siltation will adversely affect
fish and other aquatic life forms . Repopulation will gradually
occur, however, destruction of the less mobile life forms would also
occur during construction activities . In addition the easements re-
quired for the structural works would decrease the wildlife habitat
area located within the flood plains.
5. 02. The overall change in the character of the streams can be ex-
pected to induce changes in species diversity and population. Some
fish, birds or mammals may not find their preferred habitats in the
vicinity of the completed project and the populations which develop
in and along the newly modified streams may differ in dominant spe-
cies from the original conditions.
5. 07 . Depending on the point of view of the local residents , the
proposed structural works may have an effect on aesthetics . For the
Mamaroneck Project in particular, the present channel alignment
along Brookside Road is very scenic. The proposed channel modifica-
tions would alter this area. The removal of bankside vegetation
here and in other portions of the proposed projects will detract
from the present appearance as well. The aesthetic loss will be
somewhat alleviated by landscaping and replanting but several years
would pass before the levees and construction marred areas begin to
appear as a more natural part of the streambank environment.
52
6 . ALTERNATIVES TO THE PROPOSED ACTION
6 . 01. General. The formulation portions of this study involved
the development and analysis of alternative plans through repeated
iterations of the functional planning tasks (problem identifica-
tion, formulation of alternatives, impact assessment, and evalua-
tion) to achieve the planning objectives outlined in paragraphs
1. 04 to 1. 06. The formulation and evaluation of all possible altera-
tives were based on ER ' s 1105-2-200 thru 250 and 921, establishing
the planning process consistent with the Water Resources Council ' s
Principles and Standards (P&S) . Based upon the analysis and screen-
ing of alternative plans and reiterations of the plan formulation
process , plans of protection which are considered to best reflect
expressed public needs and desires, and best address the planning
objectives defined below, were selected for the Mamaroneck and
Sheldrake Rivers basin, and Byram River basin, respectively.
6. 02. Formulation Criteria. The development of alternate plans ,
including the screening of individual measures and entire alterna-
tives , must of necessity be within the contest of an appropriate
set of formulation criteria. Such criteria, technical, economic,
environmental, social and other intangible considerations , permit
the development of alternatives which would, as a minimum, make a
partial contribution to objective fulfillment while responding to
the problems and needs of the study area.
6 . 03 . Technical Criteria. The following technical criteria was
adopted for use in formulating the plans of protection examined
in this report.
a. Protection must be technically feasible for implementation
based on appropriate engineering standards and guidelines .
b. Protection should be provided against a design storm equal
to, or greater than, the Standard Project Flood. The Standard Pro-
ject Flood is a hypothetical flood that might be expected from the
most severe combination of meteorological and hydrological condi-
tions of the geographical region involved, excluding extraordinarily
rare combinations .
C . The plans of improvement must protect their respective
areas without causing adverse effects at downstream reaches .
6 . 04 . Economic Criteria. The economic criteria applied in formu-
lating plans are specified in Senate Document No. 97-87th Congress
entitled, "Policies, Standards and Procedures in the Formulation,
Evaluation and Review of Plans for Use in Development of Water and
Related Land Resources" ; ER 1105-2-351 entitled, "Evaluation of
Beneficial Contributions to National Economic Development for Flood
Plain Management Plans; and the planning ER ' s referenced in para-
graph 6. 01. Plans were initially formulated to include all units
of improvements and purposes which satisfy the following criteria:
53
a. Total beneficial contributions (economic and non-monetary)
must exceed total adverse contributions (economic and non-monetary) .
A plan must produce net National Economic Development (NED) benefits ,
unless the deficiency is the result of economic costs incurred to
obtain positive Environmental Quality (EQ) contributions (non-mone-
tary) .
b. Each separable unit or purpose provides benefits at least
equal to its cost.
C. The scope of the development is such as to provide the maxi- _
mum net benefits , except as modified for Environmental Quality,
social or community impact concerns .
d. There is no more economical means , evaluated on a compa-
rable basis, of accomplishing some purpose or purposes which would
be precluded from development if a plan were undertaken. This limi-
tation refers only to those alternative possibilities that would be
physically displaced or economically precluded from development if
the project were undertaken. The cost of alternative plans of
development were based on survey scope plan layouts, estimates of
quantities, and December 1976 price levels . Detailed estimates of
costs for the selected plan are included in Appendix E, Cost Esti-
mates , of the Feasibility Report.
6. 05. The benefits and costs are expressed in comparable quantita-
tive economic terms to the fullest extent possible. Annual costs
are based on a 100 year amortization period and an interest rate of
6-3/8 percent. The annual charges also include the cost of opera-
tions, maintenance, and replacements .
6 . 06 . Environmental Criteria. The environmental criteria applied
in the formulation of plans of protection was directed towards
achieving the National Economic Development (NED) and Environmental
Quality (EQ) as equal objectives, as required by the Water Resources
Council' s Principles and Standards, and as defined and discussed
in the National Environmental Policy Act of 1969; Section 122 of
the River and Harbor and Flood Control Act of 1970 ; and the plan-
ning ER' s referenced in paragraph 6 . 01. The following environ-
mental criteria were considered in formulating a plan:
a. The management, preservation or enhancement of biological
resources, ecological systems and areas of natural beauty and human
enjoyment, and inclusion of feasible mitigating measures for ad-
verse impacts on these resources and systems if such effects are
found unavoidable.
b. Plans should preserve, maintain or enhance the quality as-
pects of water through prevention of erosion and/or restoration of
eroded areas .
54
C. Avoidance of the irreversible and irretrievable commitment
of natural resources and biological systems which preclude future
uses .
6 . 07. Social and other ccnsiderations. The following social fac-
tors and other intangibles were considered in formulating a plan:
a. Public health, safety and social well-being, including
possible loss of life.
b. Preservation or enhancement of social, cultural, recrea-
tional, archaeological and historical, and aesthetic values in the
study areas .
C. General public acceptance, as determined by coordination
with appropriate Federal and non-Federal agencies, organized groups
and individuals, and specifically, with both the local sponsor and
study area interests .
POSSIBLE SOLUTIONS
6. 08 . General. Flood problems in the Mamaroneck and Sheldrake
Rivers basin are centered largely along the mainstreams in the
Village and Town of Mamaroneck, and also along the East Branch of
the Mamaroneck River in the Town of Harrison and the East Branch of
the Sheldrake River in the Village of Scarsdale and Town of
Mamaroneck. Along the Byram River flooding occurs principally in
the Town of Greenwich, Connecticut and Village of Port Chester, New
York. Accordingly, since flood control is the primary objective of
this study, for the possible solutions to meet the water resources
problems and needs of the Mamaroneck and Sheldrake Rivers , and
Byram River basins they must consider the reduction of flood damages
at the above mentioned problem areas. Several alternative measures
to satisfy the problems and needs of the flood areas are possible;
however, some of these measures are not practical or economical .
The possible solutions may be divided into the two broad categories
of nonstructural and structural measures. Nonstructural measures
include flood plain zoning, floodproofing, building code regula-
tions, permanent and/or temporary evacuation of floodplain areas ,
and no action (or maintaining the base condition) . Structural mea-
sures include reservoirs, diversions , channel modification, levee
and floodwall improvements, and several combinations of these. Also,
combinations of nonstructural and structural measures are possible.
6 . 09 . Nonstructural Measures . Nonstructural measures do not
attempt to reduce or eliminate flooding, but instead regulate the
use and development of the flood plain, thus lessening damaging
effects of large floods . Nonstructural solutions must reflect the
55
limitations of the various nonstructural measures and can change in
concept with an increase in flood stage of 2 to 3 feet. This can
be illustrated by considering a situation relating to a particular
residential structure. For levels of water which are lower than
the first floor elevation of a home, flood proofing would certainly
be a possibility. However, if a water level 2 to 3 feet higher is
considered, the structural stability of a water tight wood frame
house becomes a critical factor. A flood proofed residental struc-
ture generally cannot withstand hydrostatic pressures when flood -
waters reach elevations above the main floor. In addition, flood
proofing above the first floor introduces uncertainties in the
degree of protection, since the homeowner must be present to close
off windows, doorways, etc. These factors indicate that other non-
structural measures should be considered. While this illustration
does not consider the flood frequencies of occurrence, it does point
out the effect of a fluctuation of 2 to 3 feet in stage on the use
of a particular nonstructural measure. Because of these considera-
tions , criteria were established relating nonstructural measures
to the depth of flooding under design conditions . Table !: _ftrriicates
the application of several nonstructural techniques for each build-
ing category (residential, commercial, and industrial) according to
the floodwater depth referenced to the main floor of the structure.
In addition, the various nonstructural measures that may be imple-
mented are described briefly in the following paragraphs .
TABLE 10
APPLICABILITY OF NON-STRUCTURAL METHODS (a)
DEPTH OF FLOODING (b) RESIDENTIAL COMMERCIAL INDUSTRIAL
Up to main floor FP FP FP
0 to +3 feet RA FP, RA FP
+3 feet and over BO, RE FP, RA, BO, RE FP
(a) Definition of Terms: FP - Flood proofing
RA - Raise structures
BO - Buy outstructures
RE - Relocate structures
(b) Referred to main floor elevation.
6. i0. Flood Proofing. Flood proofing consists of those adjustments
to existing structures and building contents which are designed to
reduce or eliminate flood damages . Flood proofing includes , but is
not limited to, such measures as valving sewer lines , screening of
windows , sump pumps to drain seepage, sealing of cracks , steel bulk-
heads on brick walls to close off entrances, coating of walls with
a waterproof membrane, elevation of damageable property above flood
level, raising existing buildings and providing individual dikes
around existing structures . General cost guidelines for the vari-
ous floodproofing methods are presented in the Feasibility Report .
56
6. 11. No Action-Maintain Base Condition. Maintaining the base con-
dition would consist of utilizing no additional nonstructural or
structural measures to alleviate the Mamaroneck and Sheldrake Rivers ,
and Byram River consist of reliance on emergency flood protection
and temporary evacuation measures, flood plain regulations as re-
quired under Federal, State and local law, and flood insurance
available under Federal programs . All of the communities within
the subject basins are currently enrolled in the National Flood In-
surance Program.
6. 12. Other Measures . Other preventive measures could be provided
in the -flood plain, such as warning systems, use of zoning ordinances
and building codes, tax adjustments and urban redevelopment. These
measures could effectively reduce or eliminate future damage in the
flood plain.
6 . 13. Reservoirs . There are several upstream sites within the
Mamaroneck and Sheldrake River basin at which flood detention re-
servoirs are possible. These sites include two areas which are cur-
rently occupied, in part, by existing reservoirs which were for-
merly used for water supply purposes. These facilities , which were
used until recently as standby reserves to the supplies obtained
from the New York City water supply system, are Larchmont Reservoir
#2 along the Sheldrake River, and the Westchester Joint Water Works
Reservoir on the Mamaroneck River. Additional sites exist along
the Mamaroneck River at Maplemoor Golf Course, and at Silver Lake .
However, the development of a flood storage reservoir at each of
these sites is not particularly attractive because of excessive
costs and/or limited regulation and effectiveness at the downstream
areas . For example, the use of the Westchester Joint Water Works
Reservoir for flood control would require the construction of a
new dam. In addition to the new dam, several roads and highways
would have to be raised to substantial heights. The real estate
requirements for such a reservoir at this site would total more
than 200 acres . Costs for implementation of this plan would exceed
40 million dollars.
6 . 14 . Diversions. The upstream diversion of stream flow which is
in excess of the natural bankfull channel capacity at downstream
damage areas is possible when there are bodies of water into which
the diverted flow can be safely discharged without creating or
worsening flood problems. The flood damage areas along the Mama-
roneck and Sheldrake Rivers in the Village of Mamaroneck are favor-
ably located for such diversion with respect to Mamaroneck Harbor
of Long Island Sound. The damage area along the Sheldrake River in
the Town of Mamaroneck, which lies about 8, 000 feet upstream of the
confluence with the Mamaroneck River, is not suitably located for
the development of diversion type protection. To divert flood flows
from a point upstream from the town ' s damage center along the Shel-
drake River to the closest large body of water, the West Basin of
Mamaroneck Harbor, a tunnel of more than 7, 000 feet in length would
57
be required. Although this scheme could be developed to provide
flood protection at the town, such a elan like the flood detention
alternate at Larchmont Reservoir #2, has limited benefits downstream
in the Village of Mamaroneck, and would be uneconomical . In addi-
tion, variations of the tunnel scheme selected for lower Sheldrake
River were also considered . These diversion plans were the same as
the plan described in Section 1 of this statement, however, the
tunnel diameters were slightly smaller .
6 .15. Mamaroneck River Diversion. The problem area along the
Mamaroneck River in the Village of Mamaroneck lies from below the
confluence with the Sheldrake River, upstream to Winfield Avneue,
with the predominant amount of flood damage at the lower reaches
of the stream, below the New England Thruway. Therefore, to pro-
tect the heavily damaged lower reach a point of diversion was con-
sidered in the vicinity of the Thruway, approximately 7, 500 feet up-
stream from the mouth. For this diversion to protect the remaining
upper portion of the damage reach in the village, the inlet would
have had to lie approximately 3, 000 feet further upstream at Win-
field Avenue. The resulting 50% increase in tunnel length, from the
point of diversion at Winfield Avenue to the outlet in the Harbor,
to include the upper section was not considered practical because
of excessive costs . Thus, the considered scheme consists of a
point of diversion downstream face of the New York State Thruway
Bridge, leading to a diversion tunnel approximately 6 , 000 feet in
length from the inlet structure to the East Basin of Mamaroneck
Harbor. This system would divert that portion of the flood flow
which is in excess of the Mamaroneck River ' s natural bankfull capa-
city at downstream areas. It was found that to protect against
storms with recurrence intervals from 50 to 200 years , the tunnel
sizes required would be between 15 . 5 and 18 . 5 feet in diameter. Al-
though feasible from an engineering standpoint, the costs to con-
struct such size systems for the required length are excessive,
ranging up to over 40 million dollars, and the resulting schemes are
uneconomical.
6. 16 . Local Protection Measures . After most of the reservoir and
diversion considerations were precluded, it became evident that be-
cause of the physical characteristics of the watershed and location
of the damage areas the flood control objective for the study area
could best be achieved by local protection and channel modification
measures , possibly in combination with the above mentioned diver-
sion scheme for the lower Sheldrake River in the Village of Mamaron-
eck. Local protection measures such as levees , floodwalls , channel
modifications and various combinations of each were considered as
possible solutions to the flood problem along the Mamaroneck and
Sheldrake Rivers at the Village and Town of Mamaroneck.
6 . 17. Structural Measures, Byram River. A number of structural
measures exist for reducing flood damages , as well as minimizing
or preventing the occurrence of floods along the Byram River at
Greenwich, Connecticut and Port Chester, New York. These measures
58
include flood diversions, flood detention reservoirs, local protec-
tion measures such as levees, floodwalls and channel modifications ,
and combinations of each of the foregoing structures. The struc-
tural measures considered as possible solutions for the flood prob-
lems at Greenwich and Port Chester are briefly discussed in the
following paragraphs, additional information is contained in the
Feasibility Report.
6 . 18 . Diversions and Reservoirs . The problem area along the Byram
River at Greenwich and Port Chester, which lies about 9, 000 feet
upstream of the mouth, is not suitably located for the development
of diversion type protection. To divert flood flows from a point
upstream of the Byram River damage area to the closest large
body of water, Byram Harbor, a tunnel of more than 6 , 000 feet
in length would be required. Although such an improvement would
reduce fluvial flooding, damages resulting from tidal inundation
would not be prevented. The potential flood control benefits at
Greenwich and Port Chester clearly cannot support such a scheme.
Furthermore, a solution involving upstream flood detention is
also not a practical solution to the flood problem at Greenwich
and Port Chester. Any upstream detention area, through the use of
either existing lakes such as Toll Gate Pond, Wilcox Pond or Wooley
Pond, or the development of other possible sites, would lie more
than two miles upstream from the problem area. The incremental flows
generated by local runoff downstream of any potential site would be
in excess of bankfull capacity at the downstream damage area. Addi-
tionally, like a diversion scheme, upstream retention would not alle-
viate tidal flooding, and its ' excessive costs cannot be supported
by the potential benefits at Greenwich and Port Chester.
6 . 19. Local Protection Measures . After reservoir and diversion con-
siderations were precluded, it became evident that local protection
measures could best achieve the flood control objective . Local pro-
tection measures such as levees, floodwalls , channel modification
and various combinations of each were considered as possible solu-
tions to the flood problem at Greenwich, Connecticut and Port Chester,
New York.
6 . 20. Nonstructural and Structural Combinations . Providing a rela-
tively low level of flood protection by structural methods does not
appear to be a practical solution along the Mamaroneck and Sheldrake
Rivers since this would only encourage development in areas that
would still be subject to flooding from larger storms. However, at
independent reaches of stream where nonstructural measures can be
selectively substituted for structural measures , at a compatible
level of protection, overall combination plans of protection were
considered as possible solutions . Additionally, flood plain manage-
ment techniques should be considered at flood problem areas where
structural and other non-structural solutions are not feasible.
The most appropriate measure for these areas is often zoning regu-
lations which would prevent any large increases in future flood
damages .
59
DEVELOPMENT OF INTERMEDIATE PLANS
6 . 21. General. As a result of reconnaissance and preliminary type
estimates, preliminary screening and analysis of applicable measures ,
an array of alternative plans that could fulfill the study objec-
t=yes for the Mamaroneck and Sheldrake Rivers , and Byram River were
developed utilizing the measures described in the preceeding para-
graphs . To provide a common base for comparison and evaluation,
and to facilitate quantities and qualitative analyses, protection _
against a flood with a one percent exceedence frequency was used as
the protection level in the further development of alternative plans .
This degree of protection was selected because, as explained in de-
tail in later sections, complete protection against the Standard
Project Flood (SPF) is clearly not economically justified at the
study areas along the Mamaroneck and Sheldrake Rivers , and Byram
River. Additionally, protection against a flood with a one percent
exceedence frequency is considered the minimum degree of protection
acceptable in urban areas . For these reasons, the one percent de-
sign flood was used in this initial formulation of alternative
plans . In applying this approach, it was recognized that the design
storm for the selected plans of protection could actually be greater
than the one percent flood, depending on the tradeoffs between an
acceptable flood risk and socio-economic and environmental costs .
Those plans which warranted further consideration consist of schemes
containing levees, floodwalls, channel modifications, division
tunnels and non structural applications. These plans are fully dis-
played in Appendix F of the Feasibility Report. In addition, an
assessment of the likely effects of these various intermediate alter-
natives, consistent with the WRC Principles and Standards is fully
treated in Appendix G of the above report.
6. 22. National Economic Development (NED) and Environmental Qualit
(EQ) Plans. During the last iteration for alternatives considered
through the intermediate planning stage, alternates were identified
as candidate NED and EQ oriented plans for each basin. For the
Mamaroneck and Sheldrake Rivers, candidate NED Plans were designated
as Plans 3 and 4 for the lower section of the Mamaroneck and Sheldrake
Rivers in the Village of Mamaroneck, the Channel Modification alter-
nate for the upper section of the Mamaroneck River in the Village of
Mamaroneck, and Plan IV along the Sheldrake River in the Town of
Mamaroneck; candidate EQ plans were identified as the Nonstructural
Plan, Plan 5, and a plan consisting of the levee, floodwall and
channel modification features of Plan 1 for the lower section of
the Mamaroneck River in combination with the Fenimore Road tunnel
diversion for the Sheldrake River, for the lower portion of the
Village of Mamaroneck, and the nonstructural alternates for the
upper portion of the Mamaroneck River in the village and the Shel-
drake River in the town. For the Byram River, Plan 3 was tentatively
identified as the NED plan, and Plan 4 and the Nonstructural plan
were designated as candidate EQ oriented plans . The NED plans were
selected on the basis that they maximize net economic benefits in
meeting the range of planning objectives . The designated EQ oriented
plans address the planning objectives while emphasizing contributions
to preserving the existing stream environment and open space through
minimizing adverse and disruptive impacts. The designation of the
final NED and EQ oriented plans was made during the final stage of
planning and analysis.
60
ALTERNATIVES CONSIDERED FOR DETAILED ANALYSIS
6 . 23 . General. Based on the evaluations and screening studies dis-
cussed above, and in the Feasibility Report, alternative plans were
identified for the Mamaroneck and Sheldrake Rivers , and Byram River
to be carried into the final planning stage. Further analysis of
the identified alternates towards developing detailed plans that
more fully address the planning objectives, and ultimately the selec-
tion of the most desirable plans, is contained in subsequent sections .
Of the intermediate plans investigated along the Mamaroneck and Shel-
drake Rivers the following alternatives were identified for further
consideration.
Village of Mamaroneck, lower section:
Plan 3 (levees, floodwalls, channel modification)
Plan 4 (levees, floodwalls, channel modification,
tunnel diversion)
Plan 4/Plan 1 combination
Village of Mamaroneck, upper section:
Nonstructural Plan
Channel Modification Plan
Town of Mamaroneck:
Nonstructural Plan
Plan IV (channel modification)
The plans which have been identified for further consideration along
the Byram River are:
Plan 3 (levee, floodwall, channel modification and floodproofing)
Plan 4 (setback levee, and floodwall)
The structural alternative plans mentioned in the preceeding
paragraph are summarized in Tables 11 and 12 below. Detailed de-
scriptions of these plans are presented in Appendix F of the Feasi-
bility Report. A brief description of the nonstructural plans con-
sidered for detailed analysis is provided in the following para-
graphs .
6 . 24 . Village of Mamaroneck-Upper Mamaroneck River-Nonstructural
Plan. This alternate consists totally of nonstructural mea-
sures . The nonstructural measures described in previous paragraphs
were evaluated separately and in various combinations to develop this
alternate for this section of the Mamaroneck River. As part of this
plan, 15 residential structures would be floodproofed, and 16 homes
would be bought out. A flood plain management program would be es-
tablished for the approximately 10 remaining, untreated structures
in the floodplain. A flood warning device would be installed to
help residents prepare the floodproofed structures for flooding of
the Mamaroneck River. This plan would protect the floodproofed
structures remaining in the flood plain at the Village of Mamaroneck
against a flood with a one percent exceedence frequency, but road-
ways, front and back yards, etc. , would still be susceptible to
damage. The first cost for this alternative for the upper section
of the Village of Mamaroneck plan of protection is approximately
$1, 750, 000 resulting in a Benefit-Cost ratio of 1. 01.
61
TABLE 11 - SUMMARY OF PHYSICAL FEATURES OF THE STRUCTURAL INTEREIE:DiATH FLANS OF PROTECTION
FOR THE M%MARUNECK AND SHELDRAKE RIVERS AT THE VILLAGE AND TOWN OF KVIARONECK, N.Y.
R I G H T B A N K L E F T B A N K
AVERAGE LENGTH OF LENGTH OF AVERAGE LENGTH OF LENGTH OF CHANNEL LENGTH OF DIAMETER LENGTH OF
LEVEE, WALL LEVEE CONCRETE WALL LEVEE, WALL LEVEE CONCRETE WALL BOTTOM CHANNEL OF TUNNEL OF TUENEL
_ HEIGHT (ft) (linear ft) (linear ft) HEIGHT (ft) (linear £t) (linear ft) WIDTH(ft) (linear ft) (ft) (linear ft)
PLAIT 1
Mamaroneck River from:
a) Ward Ave, to Jefferson Ave. 7 , 51i 600 525 - 3 - 450 50 1,900 - -
b) Jefferson Ave. to N.E.
Thruway Ti, 9 900 850 5 311 1,500 1,900 30 3,700 - -
Sheldrake River from:
a) Mouth to Fenimore Road 9 , 7 400 1,800 611, 71i 800 900 20 3,300 - -
b) Fenimore Road to N.E.
Thruway 611, 6 1,250 1,200 - - - 30 2,500 - -
PLAN 3
Mamaroneck River from:
a) Ward Ave. to Jefferson Ave. 4 , 5 200 500 - 2 - 500 70 1,900 - -
b) Jefferson Ave. to N.E.
llhruway 411, 411 700 800 5 , 31i 800 1,900 45 3,700 - -
Sheldrake River from:
a) Mouth to Fenimore Road - , 4`-4 - 2,000 5 61i 800 1,000 25 3,300 -
b) Fenimore Road to N.E.
Thruway 5 , 3� 1,550 150 - - - 30 2,500 - -
rn
ro PLAN 4
'•Limaroneck River from:
a) Ward Ave. to Jefferson Ave. 4 , 5 200 500 - 2 - 500 70 1,900 - -
b) Jelterson Ave. to N.E. •
Thruway 411, 41i 700 800 5, 311 800 1,900 45 3,700 - -
Sheldrake River from:
a) Mouth to Fenimore Road - - - 6 - 600 - 25 650 - -
b) Feni.L•ore Road to N.E.
Thruway - - - - - - - - 11.5 3.6i1O
R 1G11T BAN K LE F1' SANK LLN-CTHOF UPPER
AVERAGE LENGTH OF LENGTH OF AVERAGE•' LENGTH OF LENGTH 0'F CHANNEL EARTH (TRAP) LENGTH OF POi:I'10 OF
PLAN LEVEE, WALL LEVEL: CONCRETE WALL LEVEE, WALL LEVEE CONCRETE WALL 8OTTO11 C1ULNNEL fLIRIE W.-,r:::'lF.�LL
HEIGHT (ft) (linear ft) (linear ft) KEIGHT (ft) (linear ft) (Linear ft) WIDT11(ft) (linear ft)(1lnear ft) RF.."OVi:D
UPPER M 4AR.ONECK RIVER
CHANNEL MODIFICATION PIAN 3 , - 1,400 - - - - 45 3,000 - -
PLAN IV
Sheldrake River from:
a) US of Brookside Pl. to 300'
DS of Briarcliff Road 4 - 125 - 4 - 200 - 12 - 1,800
b) 300' DS of Briarcliff Road
to Larchmont Gardena Lake - - - - - 12 1,500 400 YES
I 1 I l
TABLE 12 - SUMMARY OF PHYSICAL FEATURES OF THE INTERMEDIATE PLANS
FOR FLOOD CONTROL OF BYRAM RIVER IN THE TOWN OF GREENWICH, CONNECTICUT
AND THE VILLAGE OF PORT CHESTER, NEW YORK
LENGTH OF
AVERAGE LENGTH OF LENGTH OF KNEE WALL ATOP CHANNEL LENGTH OF XUMBER OF !UMBER OF
LEVEE, WALL LEVEE, WALL CONCRETE WALL EXISTING LEVEE BOTTOM CIL%NNEL BRIDGE STRUCTURES STRUCTURES
HEIGHT (ft.) (Linear ft.) (Linear ft.) (Linear ft.) WIDTH (Linear ft.) REPLAC01ENT ACQUIRED FLOOD PROOFED
LEFT BANK RIGHT BANK LEFT BANK (ft.)
Plan 3
Downstream of West Putnam
Avenue Bridges to Rex
Street 8, 10 3,400 300 800 - 40 1.950 No 1 1
Plan 4
!deet Putnam Avenue Bridges
to Rex Street 11, 12 3,400 300 800 800 - - No 10 1
rn
w
6 . 25. Town of Mamaroneck - Sheldrake River-Nonstructural Plan.
This alternate consists totally of nonstructural measures . The
techniques described above in paragraphs 6. 09-6 . 14 were evaluated
separately and in various combinations to develop this alternate for
the Town of Mamaroneck section of the Sheldrake River. As part of
this plan, 45 residential structures would be floodproofed and 30
homes would be acquired and the residents relocated. A flood warn-
ing device would be installed to help residents prepare the flood-
proofed structures for flooding of the Sheldrake River. This plan
would protect structures remaining in the flood plain against a
flood with one percent exceedence frequency, but roadways , bridges ,
front and back yards, etc. , would still be susceptible to damage.
The first cost of this alternate is approximately $3 , 780, 000 , re-
sulting in a Benefit-Cost ratio of 1. 05 .
6.26. Non-structural Plan- Byram River. This alternate consists of imolementinQ
the various nonstructurai flood control measures similar to that ce-
described for the Mamaroneck and Sheldrake Rivers Basin. The plan
includes the floodproofing of an industrial establishment, an office
complex and 61 residential structures . In addition, 80 homes would
be acquired and the residents relocated. A flood warning device
would be installed to aid in the preparation of floodproofed struc-
tures during flood periods. This plan would protect structures re-
maining in the floodplain against a flood with a one percent exceed-
ence frequency, but roadways, parking lots , front and backyards , etc . ,
would still be prone to damage. The first cost of this alternate is
approximately $9 , 400, 000 resulting in a Benefit-Cost Ratio of 0 . 6 .
6 . 27 . Contributions to National Objectives . During this iteration
of the planning process alternatives were designated as NED and EQ
plans for the Mamaroneck and Sheldrake Rivers, and Byram River, re-
spectively. For the Mamaroneck and Sheldrake Rivers , the NED plan
was designated as Plan 4 for the lower section of the Village of
Mamaroneck, the Channel Modification alternate for the upper section
of the Mamaroneck River and the Plan Iv along the Sheldrake River
in the Town of Mamaroneck. The EQ oriented plan was identified as con-
sisting of the levee, floodwall and channel modification features of
Plan 1 for the lower section of the Mamaroneck River in combination
with the Fenimore Road tunnel diversion for the Sheldrake River in the
Village of Mamaroneck, and the nonstructural alternates for the
upper portion of the Mamaroneck River in the village and the Shel-
drake River in the town. For the Byram River, Plan 3 was designated
as the NED plans, and Plan 4 was identified as the EQ plan. These
plans and their development based on the applicable criteria are
discussed below, and the resulting significant beneficial and ad-
verse contributions are displayed in the System of Accounts Tables
F14-F20 in the Feasibility Report and Tables 13 and 14 of the E . I .S .
6. 28 . Mamaroneck and Sheldrake Rivers , National Economic Development
(NED) Plan. The NED plan was selected on the basis that it max-
imizes net economic benefits, considering both scale optimization and
plan efficiency, while also addressing the range of planning objec-
tives . Of the plans considered for the upper Mamaroneck River in
the Village of Mamaroneck, and the Sheldrake River in the Town of
64
.13 -
MMIAW,NICK AND 611A.WtAM At '1411 1 kllt.f. AND TOWN
OF 11AHAVON11;K, N.Y.
PLAN A (NED PIAN) PLAN Ill
SI:I.I=Ef) PIAN (EQ ORIENTED NED PIAN) PLAN C
A. PINY. 01,1'A
Structural tleafioires
1) Mamaroneck Piver, Channel modification, retaining walls Channel modification, levees, flood- Channel modification, levees, ftoodwalls
VillaXe of ilamar(,neck, and bridge replacements. walls and bridge replacements. and bridge replacements.
downstream of thruway
2) Matioroneck Piver, Channel modification. ---- Channel modification and levee.
Village of Aii-naguneck,
Town of flsrif%.n, t,p-
stresi, of Tlir,iway
J) Sheldrake Piv4.r, Tunnel diversion, channel modification, Tunnel diversion. Channel modification, levees, walls,
Villave of :!.,.-,arnneck cetab.i.if" walls, levee.
bridge replacements.
4) Sheldrake Itiver, Chaanel modification, bridge replace- ---- Same as NED plan.
Town of Matnit,one,it ment, training levees.
:;nn•tr:rt-iral Measures
1) YanAr.n--ek Piver, ---- 15 residential structures floodprl)ofed; ----
of :!ariarr,n,!ck, 16 homes acquired.
of fhruwa-,
2) Sheldrake River, Down ---- 24 reqldei,tial strticiLirva floodproofed; ----
of Mar4roneck 15 homes acqtilred.
Lauds 32 acres of permanent easements; 25 acres of perinanent casements Includ- 46 acres of permanent easenriits including
ON 15 acres of temporary r-risf-ents. Ing the acifoLsition of 2 residential the acquisition of I indwistrial, 2 cor.-mer-
stitictures in village; 10 acres of ctal and 4 residential strtictitres; 322
P temporary erset.ients. acres of temporary easements.
A Sli.NIFICANT IMPACTS 1) Plait rc-anveis approximately 200 acres 1) [Ilan removes approximately 180 acres 1) Plan removes approximately 225 acres
from lbe .5 percent floodplain fit the from the one percent floodplain In the [runt the one percent floodplain In the
lower Villsice of Mamaroneck, 30 acres lower Village of Mamaroneck. Village and Town of Mamaroneck and Tow
from the one percent floodplain in the of Harrison.
upper Vi11aft(- of Mamaroneck and Town of
Ifn,r I!...a. and jr, acts from the one per-
cent It-didalli In the 'fown of Macwti4mieck.
2) Aip—Inately 300 homes a-,d 160 heat-al- 2) Approxiinate-ly 340 horses and 150 bust- 2) Same as EQ plan.
n—nos p—lottud from .5 percent flood nesses protected from I percenr flood
iii lower 'JillayL-of Haniaron—k. and 70 In Village and Town of Maineroneck and
homes protected from (lie I porceitt flood Town of flarrison.
In upper Village of flaniaroneck and Towne
of Mailiar,etk mid llairlson.
J) Encroachment and loss ro some of the 3) Less significant lona of some of 3) Similar to NED plan, however, these
limited fish and wildlife habitat clue the limited fish and wildlife habitat impacts would he greater doe to core
in iiii- sti—tural works along both due In less extensive striirttirol works extensive channel modification along the
stream:. and the total diversion of and the partial diversion of the Shel- Sheldrake River.*
Sheldru'Ve River. Hciltlorei to mitigate dinke 110-t In the lower Village of
tht.,v g-11-:1a would minimize these flopm,.......A fterihures to int.tfi.fre
loncc...* thpsj? IOS!ie% are J11C1,141ed. No SIR-
nifi.ant Impacts plooll the Sheldrake
kivei, or Xaniajoiteck kLvvr upas team
of Thr"WaY.A
4) Undeteimitted nuctiber of trees and 4) Undetermiiir.d nomber of trees and 4) Similar to NED plan, however. Impact
shrubs removed for construction along shrubs removed for construction of would be greater clue to more extensive
both streams In Village and Town of structural workit, along the Ma.mroneck structural works along Mamaroneck and
Mamaroneck and Town of Harrison. Pro- River downstream of 11hrioway. Project Sheldrake Rivers in Village of Mauts roneck.*
jest bercutificaLlon measures and tree beautilicaticiti measures and tree
planting program would partially replace planting program would partially re-
these losses.* place thest, losses.*
L18I.I.-13 - m!M'i wi ('(rCPAI,1.;O;; nl' 1111'"11111 II 1'1,1:11; (Con['d)
I r:!I CY Al`!!) :1-1.11-''.1 1: Cfl'l i..; A' '1'P'. 1111.101' ARO FOWN
OF t41t41R11Nhr'i., lL1.
PIAN A (NEI) PIAN) PIAN 8
SEI.Eta A) PIAN (EQ ORIENTED NI•:) PLW) PLAN C
B. Sic,SlriCA1T IMPACTS 5) Construction activities would result 5) Overall the natural rivers would 5) Temporary impacts same as NED plan,
(Cont'd) in short-term adverse impacts on appear- remain intact except along the Mama- however, increased number of levees and
ante of. project area. After construction roneck River downstream of the 'Thruway. walls would have adverse aesthetic
the structural works would have adverse Al this reach the terr.p.urury Impacts effects.*
aesthetic effects, particularly along would be the same as NI:D plan, however,
Sheldrake River in Town of Mamaroneck.* after construction the levees and walla
would present au obstacle to those who
wish to view the river and its sur-
rouud(ugs.*
6) Temporary Increases In turbidity and 6) Less significant temporary increases 6) Similar to NED plan, however, Impact
sedimentation levels from excavation In turbidity and sedimentation during would be greater due to store extensive
e within cbdnnels of tlainarooeck slid Shel- coustructlon of levees and walls end structural works in Village of Mamaroneck.
drake Rivers In Village and 'town of excavation within lite Manmrnneck River
lianmruo-1, and Tuwu of Ila.rison. Ilse channel in the Village of Manaroneck.
of erosion control measures and tempo- Erosion control measures would minimise
rely •.edis.ent bnrins or silt lost riers this impact.
screens mitild minlmixe this impact.
7) Diversion of Sheldrake River would 7) Levee at Columbus Park in Village of 7) Levees at Columbus Park and at Chestnut
result. lu aba.,duumc it of 2400' of down- Mamaroneck would reduce the available Avenue area would reduce the available
thannel and loss of habitat area. open space and associated recreational open space and associated recreational
Staguutlon pools may develop In aban- opportunities ar the park.* opportunities at these areas.*
dune, rh;...nel. lite quality of the streams
and lo:u bur is degraded and diversion 8) Acquisition of 33 homes and relocs-
should not have a significant effect tion of residents would impact on
on w.,ter quality.* community colienalon.*
C. PIA:: E7,1!rKfTON
;I-i Icr;:S ;o * Item specified in Section 122
a) Flood I,ssage 1) Approximately 300 home% and 160 1) Approximately 340 homes and 150 1) Same as EQ plan.
Pelucatlon Ioollue%ses protected frrnn .5 peucent businesses protected from 1 percent
fioud to lower Village of Marnarotueck flood In Vlllag.t and Town of Mamaroneck
and ;0 humes protected from the 1 and Town of Ila n lson.
perce•'t flood in upper Vllla,;a of
tLmmt•n...tk slid Towns of K,maruneck
and 11—riron.
2) Tetal average annual damages re- 2) Total average animal damages re- 2) Total average annual damages reduced
du,.ed by 99.947.. duced by 86:. by 80-4.
It) Stream Environment 1) 'the %rructnral works along both Overall the existing river system Similar to NED plan, however, these impacts
('.•serval inn stream!; And tine total diversion of woo-Id he preserved, except along the would be greater due to more extensive
tl.e !;hcldrake River world lnipact on Mamaroneck River dowostrc•am of the works in the village.
the limited acgnavic aur] wildlife Tin uwav where the structural works
habitat, would impact oil the limited acquatic
and wildlife habitat. Mil lgatLon
2) Mit lgat Ion mrasuree world minimize mexsu.es would lid ninJxe these impacts.
the ponnauen( el t.cts after const r.c-
ttuit.
c) Open Space Modified channel of Mamarnnec•k River levee at Columbus Park in Village of Levees at Columbus Park and at Chestnut
Preserval ion would reduce existing open space in Mamaroneck would reduce the available Avenue area would reduce the available
the Pillage of Ma.naroneck and Town of open space and associated recreational open space at these areas.
Harrison; however, since no levees opportunities at the park.
are required, the permanent impact at
Columbus Park would be minimal.
r t 77 a 41
IAli If: Lq3' o... "S' t!r"'. i.l St Jl •1F fill::'If ltt, :,Lv:.,
MAHARo NECK AND :6t1it.U::AI.I. R::'fiGS At 1.1C Vlld.C:ri AND TOWN
OF MMItUMNECk, N.Y.
PIAN A PIAN B
(NED PLAN) (EQ ORIENTED NED PLAN) PLAN C
2. NAT 10NAL ECOKOHIC
DLVELOP:ll.:rr
Beneficial $3,060,000 $2,560,000
$2,090,000
Adverse $2,230,000
$1,990,000 $1,550,000
.let $ 830,000
$ 570,000 $ 540,000
NED I—elit-cost
ratio 1.4: 1.3 1.3
3. ENV 1 P"1:8IEM AL QUALITY
a) Quality of Vater, Air* Temporary adverse effects to air Less significant negative contribution Similar to NED plan, however, impacts
and Land Resugrces and water quillty during construction than NEI) plan, as sunmwrized above in would be greater, as summarized above
and vegetative resources would be SIGNIFICANT IMPACTS section. in SIGNIFICANT IMPACTS section.
lost, as stommarized above in SIGNIFI-
CANT' IMPACT'S section.
b) Fish and Wildlife Eneronchment and loss to acute of the Nonstructural measures along upper Similar to NED plan, however, impacts
Resources limit-ed habitat area would r-esult, as Mamaroneck and Sheldrake Rivers and would be greater, as summarized above
sutmnarized above in SIGNIFICANT tunnel diversion along lower Sheldrake in S]GNIFICANT IMPA TS sectlon.
01VACTS section. River would result In minimal impacts
to fish and wildlife resources. -
c) Ilistorical-Archeo- Cultural resources survey indicated no Same as NED plan. Same as NED plan.
Q� logical Resources* sites eligible for National Register.
W d) Aestbetica* Temporary adverse effects to appear- Overall the natural rivers would re- Temporary Impacts same as NED plan, how-
F.. ance of project area. After construe- main intact except along the Mama- ever, increased number of levees and
P'• tion the atroctural works would have rnaeck River downstream of the Thru- walls would have adverse aesthetic effects.
negative aeslhetia Impacts, partic— way. As stmmarized above in
larly alwig Sheldrake River in Town. SfCA'IFTCANf IMPACTS section, the
levees and walls along the Mamaroneck
River would have adverse aesthetic
effects.
4. kE.G]''iAL Dr.'EIJ)PtIL;7r Increased employmenr oppurtunity for Same as NED plan. Same as NED plan.
consir-tion workers during construc-
t ioil.
+
5. SOCIAL l•IELL-BEING
a) Life, Ilealth, and l:educed threat to life, health and Same ns NED plan. Same as NEI) plan.
Safety safety of residents.
b) Displacement of No people would be displaced. 33 I-mss would he acquired and the I industrial, 2 commercial and 4 residen-
People* residents relocated. tial structures would be acquired.
c) Income Effect . Increased lmploymenr during construe- Same oa NED plan. Same as PIED plan.
t ion.
d) Recreation* Temporary reduction of recreational Levee at Columbus Park would reduce Levees at Columbus Park and at Chestnut
upportunitfes at Columbus Park and at the avallable open space and assort- Avenue area would reduce the available
Che.atrint Avenue area during construe- steel ret reation opportunities at the open space, and associated recreational
tion. park, opportunities at these areas.
TABLE -SO1111ARY COMPARISON OF IDEI7FIFIF.D PLAINS (Cont'd)
HAMACnNi.CK ANO Slll'.1.10Lll:li RIVtliS A'1' TILE VLI.LAOE AND TOWN
OF MAMARONECK, N.Y.
PLAN A PLAN B
(NED PLAN) (EQ ORIENTED NED PLAN) PL%N C
a
D. IMPLL:1l.;'1 A'f IQN
RESPONSIis11.111FS
1. Federal Federal first cost of 529,530,000 Federal first cost of $25.480,000 Federal first cost of $17,009,000
would be W. of total first cost, would he Sit of total first cost. would be 72% of total first cost.
2. Non-federal lion-Federal first cost of $4,870,000 Non-Federal first cost of $5,030,000 Non-Federal forst cost of $6.500,000
would he 14% of total first coat. would be 167.. of total first cost. would be 28'. of total first cast.
Lando, rights-of-way and easements Lands, rights-of-way and easements Lands, ril•hts-of-wa% and easaments
account for largest posit loo thereof. account for largest portion thereof. account for largest portion thereof.
Operation and maintenance coats esti- Operation and maintenance costa esti- Operation and maintenance Costs esti-
mated at $33,0110 annually would be sated at $30,000 annually would be mated at $44,000 annually would be
local responsibility. local responsibility. local responsibility.
lT
W
r•
r•
a
• , Y 4
TABLE t14- S1R111IARY COMPARISON OI' LITEN'FIFIED PLANS
BYRAM RLVP.I,' A'l' GRI:EMICII, CONN. AND
PORT CIILS':f•:R, N.Y.
PLAN 3 (NED PLAN) PIAN 4
SELECTED PLAN (EQ ORIENT'FD NED PLAN)
A. PLAN DATA
Structural measures Combination of levee, floudwalls and channel modification. Setback levee and floodwall.
Nonstructural One structure floodproofed; regulatory zoning within flowage one structure fioodproofed; regulatory zoning within flowage
measur..s easements. easewents.
lands 20.9 acres of permanent east•ments; one residential structure 22.5 acres of permanent easements; ten residential structures
acquired;•2.9 acres of temporary easements. acquired; 3.1 acres of iempurary easements.
B. SIGNIFICANT' INPACIS
1) Ilan removes approximately 54 acres from the one percent 1) Same as NEI) plan.
floodplain.
2) Approximately 140 homes and 5 buniuesses protected from 2) Same as NED plan.
damage from one percent flood.
3) FStc rose hsient and loan to some of the limited fish and 3) Acquisition of ten hnmes and relocation of residents would
wildlife habitat. Measures to mitigate these effects impact on community cohesion.*
wcold r..inimize these losses.*
4) Undetermined number of trees and shrubs removed for 4) Construction of the setback levee would rem_sve a less
conntru,�l Ion. Project beautification measures and tree significant number of trees and shrubs. Project beauttli:a-
planting program would partially replace these losses.* tion measures would furt:ier ninlmlze this Impact to rtud,
area.
:) Scmpotary Increases In turbidity and sedimentation levels S) Less significant temporary Increases In turbidILV and
d—ii.g construction of levees and valla, and from excavation sedimentation levels from denuded side stoles of levees and
within channel. Use of erosion control measures and tempo- from excavations during floodwall construction. Erosion
rat i t.e•Iinwut basins or silt barrier screcus would minimize controt measures would minimize this i•npact.
this Iml.atL.
6) Construction ac U vitles would result in short-term 6) Same as NED plan, except constructian activities. and the
adverse Impacts on the appearance of the project area, associated adverse impacts, would be carried into the upstream
Allcr cans:rust Jon the levee and walls would pt.sent. an Pemberwick area.*
ol,ctacle to those who wish to view the river.*
C. PI hN F;""i IJAI I'll:
Item specified in Section 122.
a) Flood Damap,e 1) Approximately 140 basics and 5 businesses protected from 1) Same as NED plan.
Peductlon danoge from one percent flood.
2) IoLal average ::nnUal damages reduced by 95%. 2) Total avernge annual damag.•s reduced by 92''..
b) .Stream Environ- 1) Itowttstienm of Pemberwlck Lake the channel modification The existing river system would be preserved, however, con-
etent Preserva- of the Bytam River would impact on tate limited acquatie st tact ion activities along the banks would result In some
tion slid wildlife habitat. disruptive impacts.
2) Mittitation measures would minimize the permanent effects
after construction.
c) F'aintain Pember- A low sill would be constructed to maintain the present lake would be preserved fn Its existing condition.
wick Iake water surface elevstloos of the lake.
1.161!: -14 - Sunmity comm isoN OF IFIED PIANS (Cont'd)
ItYRAM RICER AT GRUI.-WICII, CONN. AND
PORT CHESTER. N.Y.
PLAN 3 (NED PLAN) PIAN 4
SELECTED PLAN (EQ ORMTED NED PLAN)
2. NAI I(Y AL ECO:XMIC
DC:FL0?ME;T
Beneficial $488,300 $448,500
Advarse $309,000
$346,UOC
?.'at $179,300
$102.500
::LD !-ensflt-coat
ratio 1.6
1.3
3.
a) Qcality of Temporary adverse effects to air and water quality during Similar to NED plan. Set back levee would result In le.$ en-
. 11•r, Air, e,atstruction and some v.getative resources would be lost, tensive vegetative loss.
sed L.,A ac suni.arized nbove in SIGNIFICANT IMPACTS section.
"t-tou rc c s
b) Plsh and F.ncrrachment and loss to some of the limited habitat area Negative contributions would bo similar to ::::;7 pl.ro; however,
�:lldllfe would result, an summarized above In SIGt:IFIC,II:T IMPACTS these fo-r-acts wuuld be miniowl.
Pe.%rces section. Mitlgallun measures would mininilze these losses.
01
_r_ c) Ilistwrical- Cult"Fal reso::rces survey has Indicated no sites eligible Same as NED plan.
Cr Archaeol•:Rie' for I:at:onal Pegister.
r,, al Pe,ourcea
d) Aesthetics T.mpurary •Averse effects to appearance of project area. Sar..e as NED plan, how.ver, construction ac:tvities voc:C cutr)
After construction levees Gild walls would present an ob- the associated impacts upstream Into the Pembervick arae.
stacle to those who wish to view river.
4. FF.C.I�•"AL DE'.'LIn?- Increased empiuymeor opportunity for construction workers Same as NED plan.
ML:, during construction.
S. :)CL\1.::ELL-i i.1:4
e) Life, health 1) Apprualm.rtcly 140 homes and S business** protected Same a NED plan.
and Safety from one percent flood.
2) Reduced threat to life, health and safety of residents.
b) Lleplacprvnt One residential structure would he acquired and the Ter, homes would be acquired and the residents relocated.
of People residents reloc.rted.
c) Inca.e Effect Increased employment opportunity during construction. S;.me as NED plan.
d) Recrestioo -No recreational facilities ler ureas would he affected. Same as :;ED plan.
D. IYPLF_17';ATION RE-
SPONSICILITIES ,
1. rtderal Federal first 'oat of $3,540,000 would be 79% Federal first cost of $3,560,000 would be 70'. of
total first cost. total filet cost.
2. Now-rederal Non-Federal first cost of $935,000 would he 21% Non-Federal first cost of $1,560,000 would be 30% of
total first cost. Lands, rights-of-way and easements total first cost. Lands, rights-of-way and esseaer.te
account for largest portion thereof. Operation, main- account for largest portion thereof. Operstioa, a ln-
tenance and replacement costs estimated at $23,000 tanance and replacement costs estimated at $18,800
annually would be local responsibility. annually would be local responsibility.
Mamaroneck, the Channel Modification Plan, and Plan IV, respectively,
produce the greatest net economic return. For the lower Mamaroneck
and Sheldrake Rivers, Plans 3 and 4 produce the highest net excess
benefits. These intermediate plans both considered protection
against a flood with a one percent exceedence frequency. However,
when the scale of development and level of protection are considered,
and recognizing the benefits occurring from advance replacement, re-
development and less frequent pavement resurfacing Plan 4 results
in the greatest economic return for the lower Vii.Ldge of Mamaroneck
portion of the study area, as shown on Table 13 . Thus the NED plan
for the Mamaroneck and Sheldrake Rivers would consist of Plan 4 , the
Channel Modification alternate, and Plan IV, for their respective
portions of the study area. The description of the NED Plan elements
and the level of protection considered is contained in Section 1 on
the final development of the NED plan.
6 . 29. Environmental Quality (EQ) Plan. The EQ (EQ oriented NED) plan
was selected on the basis that it addresses the planning objectives for
the Mamaroneck and Sheldrake Rivers while emphasizing beneficial con-
tributions to preserving and maintaining the significant portions
of the existing stream environment, aesthetically pleasing sections
of stream, and open space within the study area . The plan which
provides the greatest net positive contributions to the above-men-
tioned components of the National objective of Environmental Quality
consists of the levee, floodwall and channel modification features
of Plan 1 for the lower section of the Mamaroneck River, in com-
bination with the Fenimore Road tunnel diversion for the Sheldrake
River in the Village of Mamaroneck, and the nonstructural alterna-
tives for the upper portion of the Mamaroneck River in the village and
the Sheldrake River in the town respectively. The level of protection
of the EQ oriented plan is considered optimum at the one percent
frequency flcod, as formulated. A higher level of protection, would
result in more extensive structural works along the lower Mamaroneck
and Sheldrake Rivers , thus increasing adverse EQ contributions ; simi-
larly, a lower level of protection is not consistent with the flood
damage reduction objective. The significant positive contributions
made by the elements of the EQ oriented plan are outlined below:
1) The flood proofing and relocation measures along the Shel-
drake River in the Town of Mamaroneck would preserve and maintain
the scenic section of aesthically pleasing features and human enjoy-
ment at this reach. Additionally, these nonstructural measures
would not result in any adverse or disruptive impacts to the fishery
resources downstream at Larchmont Gardens Lake.
2) The nonstructural measures proposed at the Village of Mama-
roneck area upstream of the New England Thruway would preserve the
less stressed fish and wildlife resources and moderately undeveloped
woodlands at this reach of the Mamaroneck River.
3) The diversion of floodwaters in excess of the bankfull capa-
city of the Sheldrake channel would provide protection along the
Sheldrake River in the village while preserving the existing stream
environment. Additionally, the base flow maintained downstream of
Fenimore Road would approximate the natural flows at this reach of
65
stream. Although limited wildlife habitat remain within this reach,
the present resources would be preserved, and a future potential for
enhancer:.�nt is maintained.
The significant economic, environmental, and social effects
of the EQ plan for the :Mamaroneck and Sheldrake Rivers are summarized
in Table 11.
6 . 30. Identified Plans. As discussed in the previous paragraphs ,
the NED and EQ oriented plans were identified for the Mamaroneck and
Sheldrake Rivers during the detailed planning stage. To facilitate
further analysis and comparisons , the identified plans are rede-
signated, for clarity, as shown below.
PLAN A (NED Plan) - consists of refinedversions of Plan 4 for the
lower portion of the Mamaroneck and Sheldrake Rivers , the Channel
Modification alternate for the upper section of the Mamaroneck
River in the Village of Mamaroneck, and Plan IV for the Sheldrake
River in the Town of Mamaroneck. A description of the NED plan,
is contained in Section 1.
PLAN B (EQ Plan) - consists of the Plan 4/Plan 1 combination for
the lower Mamaroneck and Sheldrake Rivers; and the Nonstructural
Plans for the upper Mamaroneck River in the village, and the
Sheldrake River in the town, as described in the applicable por-
tions of paragraph 6. 31 and Tables 11, and 13 .
PLAN C - consists of Plan 3 for the lower Marraonreck and Sheldrake
Rivers; the Channel Modification Plan for the upper portion of the
Mamaroneck River in the village, and Plan IV for the Sheldrake
River in the town, as described in Tables 11, and 13 .
6. 31. Comparison of Identified Plans . A comparison analysis is
used to provide a basis for plan selection. The process used to com-
pare the identified plans consists of a trade-off analysis of the
contributions to the planning objectives, the beneficial and adverse
effects of each alternate, and the responses to specific evaluation
criteria such as tests of acceptability, effectiveness , efficiency
and completeness. This type of comparison categorizes the various
impacts and displays each plan in terms of the components of the
system of accounts. A summary comparison of Plans A (NED plan) , B
(EQ plan) and C along the Mamaroneck and Sheldrake Rivers is con-
tained in Table 13 .
6 . 32 . Examination of the data in the above-mentioned tables for
the Mamaroneck and Sheldrake Rivers indicates the significant trade-
offs made between the identified plans. The major monetary bene-
ficial effect that would result from the alternate plans is the re-
duction of existing and future flood damages at the Village and Town
of Mamaroneck, New York. The NED plan produces the greatest amount
of gross economic flood control benefits . With respect to adverse
economic effects, the differences between the plans is the higher
cost for the NED plan as compared to the EQ plan and Plan C. How-
ever, the greater costs of the NED are partly attributed to the
66
higher levels of protection it provides . For this plan, the levels
of protection along reaches in the Village of Mamaroneck range from
protection against a flood with a . 5 percent exceedence frequency
to the Standard Project Flood; in the Town of Mamaroneck the design
storm is the 1 percent flood. Both the EQ plan and Plan C protect
the village and town against a flood with a 1 percent exceedence
frequency. But more significantly, the NED plan achieves the flood
damage reduction objective while maximizing net positive NED bene-
fits. However, the EQ plan achieves the flood control objective
while best preserving the existing stream environment of the
Mama-roneck and Sheldrake Rivers, and the natural setting of the upper
Sheldrake River in the Town of Mamaroneck; Plan C and the NED plan
would each result in greater negative EQ contributions, although
measures are included to mitigate the adverse effects of the channel
modification features of the NED plan, as outlined in paragraph 6 .33 .
6 . 33. Another significant tradeoff also contributes to the analysis
of the identified plans. As outlined in Table 13, Plan C requires
the greatest total amount of real estate, approximately 46 and 32
acres of permanent and temporary easements, respectively, including
the acquisition of one industrial, two commercial and four resi-
dential structures. This plan would result in negative contribu-
tions to the preservation of open space planning objective and
would greatly disrupt the community during construction. The NED
plan would require 42 and 20 acres of permanent and temporary ease-
ments , respectively and the EQ plan' s real estate requirements for
its structural works consist of 25 acres of permanent easements and
10 acres of temporary easements, including the acquisition of two
homes . The social impacts associated with the real estate require-
ments of each of the plans should be noted. The EQ plan, in addi-
tion to the two homes to be acquired mentioned above, would impact
on the residential community since 46 additional homes would be
acquired and the residents relocated as part of the nonstructural
portions of the plan at the upper village and town. The NED plan
would not require the acquisition of any residential, commercial or
industrial structures. Additionally, the NED plan, which does not
include protective levees and floodwalls in the Village of Mamaron-
eck, would best preserve the existing open space and associated re-
creational opportunities at the Columbus Park area. Plan C, and to
a lesser extent the EQ plan, require a number of discontinuous levees
and floodwalls in the village. Both these plans would reduce the
available open space at Columbus Park.
6. 34 . An additional consideration in comparing the identified plans
involves the residual damages and disaster potential associated
with each plan. In the Village of Mamaroneck the tunnel diversion
and channel modification features of the NED Plan enable it to re-
duce the elevation of floodwaters for all storms up to the SPF . In
fact, when considering freeboard, the works proposed by the NED plan
at reaches along the Mamaroneck and Sheldrake Rivers in the village
would contain flows ranging from the . 2 percent storm to the SPF.
However, for Plan C along the lower Mamaroneck and Sheldrake Rivers ,
67
and the EQ plan along the lower Mamaroneck River, less frequent
floods which would result in stages greater that. 3 feet above the
one percent design level would top the levees and floodwalls in the
village. The residual damages in the Village of Mamaroneck corres-
ponding to the SPF stages for the NED plan, EQ plan and Plan C are
approximately 1 million, 30 million and 60 million dollars , respec-
tively. At the upper Mamaroneck River in the village, and Sheldrake
River in the Town of Mamaroneck, the channel modification features
proposed in the NED plan and Plan C would reduce the stages of floods
above the one percent design level, the nonstructural features of
the EQ plan at the upper Mamaroneck and Sheldrake Rivers would not
reduce flood stages, or residual damages for the SPF, at those areas .
6 . 35 . The Selected Plan. The development of the most desirable
plan of protection for the Mamaroneck and Sheldrake Rivers study
area involved the comparison and tradeoffs among the identified plans ,
as described in Section 1. At the completion of t---' s final iteration
and based primarily on the comparative analysis, and input from local
government agencies and the public, the selected plan was identified
as the NED plan, as shown in Figures 2 and 3 of the main body of
this report.
6 . 36. BYRAM RIVER, National Economic Development (NED) Plan. The
NED plan was selected on the basis that it maximizes net positive
economic benefits while addressing the array of planning objectives
for the Byram River study area . As shown in Table 12 for the Byram
River at Greenwich, Connecticut and Port Chester, New York, Plan 3
produces the greatest net excess benefits over costs . Thus Plan 3
is designated as the NED Plan.
6. 37. Environmental Quality (EQ) Plan. The EQ (EQ oriented NED) plan
was designated on the basis that it addresses the planning objectives
for the Byram River while emphasizing positive ecological and aesthetic
contributions including the preservation of the existing stream environ-
ment and Pemberwick Lake. The identified plan which provides the great-
est net positive contributions to the above-mentioned components of
the National objective of Environmental Quality is the setback levee
alternate, Plan 4. This plan would result in minimal adverse effects
to the aquatic habitat since channel modifications are not included .
Although the existing fishery resources are limited at the lower
portion of the study area, Plans 3 ' s reduced effects to the channel
environment would preserve the resources at the upper end of the
study area, and offer a future potential for enhancement downstream
of Pemberwick Lake. Additionally, the use of setback levees would
preserve the bankside vegetation along the stream. Erosion and
sediment control measures are proposed during the construction acti-
vities to prevent negative siltation impacts to water quality at the
study area and at downstream reaches. Finally, trees and shrubs
which would be eliminated by the levee construction would be re-
placed through beautification measures and a tree planting program.
68
6. 38 . Comparison of Identified Plans . A comparison analysis is
used to provide a basis for plan selection. The process used to
compare the identified plans consists of a trade-off analysis of
contributions to the planning objectives and the beneficial and ad-
verse effects of each alternate, and the responses to specific
evaluation criteria such as tests of acceptability, effectiveness ,
efficiency, and completeness. This type of comparison categorizes
the various impacts and displays each plan in terms of the compon-
ents of the system of accounts. A summary comparison of Plans 3
(NED) and (EQ) along the Byram River is contained in Table 14.
6 . 39 . Examination of the data in the above-mentioned tables for
the Byram River reveals the significant tradeoffs made between the
identified plans. The major monetary beneficial effect that would
result from the alternate plans is the reduction of existing and
future flood damages at Greenwich, Connecticut, and Port Chester,
New York. With respect to adverse economic effects, the difference
between the plans is the higher cost for the setback levee plan
(Plan 4) as compared to the combination charnel levee plan (Plan 3) .
But more significantly, Plan 3 achieves the flood damage reduction
objective while maximizing net positive NED benefits; Plan 4 does
not maximize the economic return, although it does produce posi-
tive net benefits . However, Plan 4 achieves the flood control ob-
jective while preserving the existing stream environment; Plan 3
would result in greater negative EQ contributions, although mea-
sures are included to mitigate the adverse effects of the channel
modification. Additionally, it is noted that the 40 foot base width
modified channel considered in Plan 3 is the narrowest and least
disruptive of the channel improvements considered in the inter-
mediate planning stage.
6 . 40. Another significant tradeoff also contributes to the analy-
sis of the identified plans. As outlined in Table 14, the total
amount of real estate required as easements is approximately equal
for both plans , although Plan 4 would require about 1 more acre of
permanent easements. However, the social impacts associated with
the real estate requirements of the plans should be noted. The
land required for the setback levee (Plan 4) would impact on the
residential community since ten homes would be acquired and the
residents relocated. Furthermore, the knee walls to be constructed
atop the existing levee at the upstream Pemberwick project as part
of Plan 4 would have a negative aesthetic impact on that area, and
would also carry the temporary effects associated with the construc-
tion activities into this reach of the Byram River. The real estate
requirements for Plan 3 are, in general, closer to the stream and
would not result in widespread disruption to the community since
one home would be acquired, and only minor work would be necessary
` at the Pemberwick area.
6 . 41. An additional consideration in evaluating the identified
plans concerns the possibility of floodwaters overtopping the levees
and floodwalls of either plan of protection. The channel modifica-
69
tion features of Plan 3 enable it to also reduce the elevation of floodwaters
for storms greater than 3 feet above the design level.
6.42. The Selected Plan. The development of the most desirable plan of
protection for the Byram River study area involved the comparison and
tradeoffs among the identified plans, as described in paragraphs 6.36-6.38
and presented in Table 14. At the completion of this final iteration and
based primarily on the comparative analysis, and input from local government
agencies and the public, the selected plan was identified as the DIED plan.
70
7. THE RELATIONSHIP BETWEEN LOCAL SHORT-TERM USES OF MAN ' S ENVIRON-
MENT AND THE MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUC-
TIVITY.
7. 01. General. As in the development of most urban flood-control pro-
jects, certa n trade-offs must be involved, particularly in terms of
shortterm losses in biological productivity in order to achieve long-
term protection of socio-economic resources . Construction activi-
ties will have short-term adverse impacts as discussed earlier. In
return for these temporary adverse conditions, local residents will
gain protection from future floods. Flood protection will eliminate
some infiltration of water into storm sewers, prevent sewerage back-
up in homes and prevent disruption of some public services , thereby
tending to reinforce existing land use patterns . With regard to bio-
logical productivity and aesthetics the losses which may occur will
be more enduring.
7 . 02. It is expected that the use of the flood plain for commer-
cial and industrial purposes will continue on a long-term basis with
or without the proposed project. Thus , it can be anticipated that
the natural environment, especially vacant areas in open field and
flood plain forest and along the watercourses, will continue to de-
teriorate. The threat of flooding would also continue to perpetuate
the demoralization of the community and the periodic loss of personal
and corporate economic positions. The proposed project is expected
to stimulate a feeling of security that would assure the maintenance
and enhancement of long-term productivity of protected areas . The
resulting improvement in individual and corporate efficiency and
citizen morale should greatly enhance the quality of life.
7. 03. Since short-term use of the environmental resources is not
proposed in this project, an expenditure or basic natural resources
is deemed justifiable to produce long-term social betterment and
economic stability. it is considered tnat the expenditure or readily
available natural resources iocatea within the project bounaaries or
elsewhere, are reasonable trade-ofrs for improvement of the project
area' s human environment by afroraing flood protection.
7. 04. An additional efrect of the project would be the concentration
of man' s activity in an area already greatly altered by man. As a
result, alteration of the remaining natural flood plain environment
may be spared. However, any required acquisition costs resulting in
long-term tax burdens on the community to pay foz local costs in addi-
tion to loss of tax revenue must be subtracted from total project
oenefits to appreciate net worth.
71
8 . IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES WHICH
WOULD BE INVOLVED IN THE PROPOSED ACTION SHOULD IT BE IMPLEMENTED.
8. 01. Resources that will be absolutely irretrievable after pro-
ject implementation are construction materials and labor . Besides
the actual construction materials, fuel and electricity will be re-
quired during construction and manpower will be necessary both for
construction and for periodic maintenance.
8 . 02. Some physical and biological resources will be committed for
the life of the projects. The flood control projects, when properly
combined with flood plain management will require commitments of
lands and would serve to regulate land use for the future. The
effects of such commitments will be beneficial to the existing park
areas within the flood area and to the other existing open spaces
along the streams. Some trees and bankside vegetation will be lost
and landscaping will be necessary to replace some of these resources .
It is also possible that some long-term losses in fishing produc-
tivity could result.
72
9 . COORDINATION
9 . 01. The process of preparing the Environmental Impact Statement
and the Feasibility Report involved coordination with several fed-
eral, state, and local agencies as well as public meetings during
the plan formulation stage.
9. 02. Public Participation. A public hearing was held in White
Plains, New York on 24 January 1956, by the District Engineer to
obtain the views of local interests as to what could be done to
alleviate the flood problems along the various streams of West-
chester County, New York, and the Byram River, New York and Conn-
ecticut. Flooding resulting from the overflow of the Mamaroneck
and Sheldrake Rivers, and Byram River was discussed. At this hear-
ing local interests at the Village and Town of Mamaroneck, City of
New Rochelle, Village of Port Chester, New York and Town of Green-
wich, Connecticut expressed desires for some type of flood control
improvement. Subsequently, many public hearings, meetings with
local officials and small meetings with local citizens were conduct-
ed in connection with flood control studies along the Mamaroneck,
Sheldrake and Byram Rivers previously discussed. In addition, plan
formulation stage public meetings were held in Greenwich, Conn. on
30 October 1975, and in Mamaroneck, New York on 29 March 1976, to
obtain views and comments of local interests and other interested
parties regarding the flood control improvements along the Byram
River, and Mamaroneck and Sheldrake Rivers, respectively, which
are under study in this report. A late stage meeting was held for
both study areas in Rye, New York on 31 January 1977 to further
acquire views and comments of local interests and to obtain assur-
ances of local cooperation.
9 . 03 . Subsequent to the late stage public meeting the proposed
flood control works for the upper section of the Town of Mamaroneck
(that is the proposed flume and trapezoidal earth channel beginning
at a point 300 feet below Briarcliff Road and ending in the vicinity
of Hickory Grove Drive) were eliminated from the selected NED Plan.
The Town of Mamaroneck, in response to the desires as expressed by
local residents, requested that no further consideration of flood
control measures be given to this reach of the Sheldrake River .
The local interests considered the existing flood risk more accept-
able than the socio-economic and environmental impacts to the area
resulting from the construction activities and the structural works .
9. 04. Governmental Agencies . The following government agencies
have been contacted and coordinated with in the preparation of the
Draft Environmental Statement and Feasibility Report (Appendix H,
Feasibility Report for Flood Control Mamaroneck and Sheldrake Rivers
Basin and Byram River Basin, contains copies of all pertinent
letters of coordination. The Report is available for inspection at
the New York District Office) :
73
FEDERAL AGENCIES
Dept. of the Interior
Fish and Wildlife Service
Bureau of Outdoor Recreation
Geological Survey
National Park Service
Dept. of Agriculture
Soil Conservation Service
Environmental Protection Agency
Dept. of Transportation
Dept. of Commerce
National Marine Fisheries Service
Advisory Council on Historic Preservation
STATE OF NEW YORK
Dept. of Environmental Conservation
Dept. of Parks and Recreation
State Historic Preservation Office
STATE OF CONNECTICUT
Dept. of Environmental Protection
Historical Commission Office
South Western Regional Planning Agency
LOCAL GOVERNMENT
Town of Mamaroneck
Village of Mamaroneck
Town of Greenwich
Village of Port Chester
74
Comments on Draft Statement
(1) U.S . DEPARTMENT OF AGRICULTURE, Forest Service
Comment: The effects of maintenance on water quality (p. 35-36)
and other environmental factors are not clearly de-
scribed for receivers who did not participate in the
program.
Response: Please refer to the revised section 4 of the EIS .
Comment: There is no mention of sediment produced during main-
tenance. Removal of vegetation will cause significant
erosion and increase sedimentation.
• Response: The maintenance of the project would be a local re-
sponsibility. Maintenance operations generally would
require the removal of debris deposited in the stream,
and the inspection and care of the structural works.
All work performed would be in accordance with the
applicable federal or local regulations . (refer also
to paragraphs 4. 05, 4. 06 and 4. 10 of the Revised EIS) .
Comment: Sowed and planted vegetation will need to be monitored
to ensure that it becomes stabilized.
Response: Should the proposed plan be implemented, contractor
personnel would be required to monitor sowed or plant-
ed vegetation.
Comment. Portions of paragraph 4 . 20, lines 4 and 5, and lines
16 to 20 should be clarified.
Response : Paragraph 4. 21 of the REIS has been revised accordingly.
(2) U.S . DEPARTMENT OF AGRICULTURE, Soil Conservation Service
Comment: The statement would be improved by clearly stating
whether or not prime and unique farmlands will be im-
pacted by the proposed project.
Response: Concur, no prime or unique farmlands exist within the
project area ( see Paragraph 4 . 05)
Comment: Paragraph 3. 07 could be improved by stating "usuable
topsoil will be salvaged, protected and reused in con-
struction" . The last sentence might state "excess
spoil material generated will be stabilized, and pro-
tected from erosion.
Response: These procedures will be utilized. Paragraph 3. 07
• has been revised.
Comment: The third sentence and last complete sentence on para-
graph 4. 09 should be stated more clearly.
Response: Paragraph 4 . 09 has been revised.
75
9L
•quauragP4s
pasTAaa aqq oq pappp uaaq 9APg sgdPabPZPd TPuOT4TppV :asu�ocsag
• (tZ• t • apd) aoq.zPg aq-4 UO 9AP14 TTTM buTbpaaP 9144
409979 4PgM PUP paOPTd aq TTTM TPTZagPur pabpaap STg4
9a9gM ,�;T4U9PT pTnogs 4u9ur94P4s TPuz3 9141 •pabpaap
aq pTnoM aogapg N09UOapumN 4Pg4 S94POTPUT SI20 9141 :-4Uaunuo0
•9OTJJO gOTagsTQ xao� MaN 9,q44P M9TA91 ao3 9TgPTTPAP ST goigM ',4Zodag 1Z4TTTgTspaj
aqq uT paUTPgUoO gap 's4u9uraatnbaa TPT294Pw TTTJ
buTpnTOuT ' sgsoo goaCoad buipapbaa sagpurzgsa PGTTP49C
• saTOuabp TPOOT aO 94vgs 9TgpOTTddp 9q4 g4TM UOT4PUTpaO
-00 a949P s94zs dump panoaddp 4P Pa4Tsodap aq pTnOM
9TgpgTnsun punog TPTa94PW • s9bP4S buTUUPTd ubzsaP
P9TTP49p 91q4 bUT2np appul aq pTnoM SUOT4PUZIua949p asagl :asuodsag
•sgsoo goe[oad goazgp pTnoM TPza94PUI TTT9
pap9au [SUP go aspgoand a14-4 Moq pup pasodsTp aq pTnoM
TPTa94PuI 9TgPgdaoopun aqq 9a9gm 94POTPUT pTnogs pup
STg4 SSnOSTp pTnogs SI3 TPuT3 aql •p9uiulaa4ap uaaq
40u sPq TPza94Pur Pabpaap 9144 90 A4TTT9P4Tns 9g4 Zana
-Moq ' saanaT go uoTgonagsuoo aqq uT pasn aq TTTM sa9ATa
9q4 uroag sTPTZ94Pw pabpaap 9q4 4Pg4 S94VOTPUT SIaC 9141 :-4uauInIoO
• S409gg9 asaanPP
9zTurTuTur Oq p9zTTTgn saanspaul UOT4V5T4Tul 9144 buOUIP aq
TTTM saanspaui Toa4uoo quaurtpas Zaggo ao suaaaos 4TTS :asuo ag
•uaxpq gap saanspaur UOT4P5T4TuI a9doad ssaTun
dpaq quguripas P SP 40P TTTM 9XPZ SuapaPO 4uou11431PI :quaunuo0
II uOz59g 'T,ONaOK NOI103102id 'IVIN3WNOUTAN3 ' S'n (DI)
•90TAagS
S9Ta9gsz3 PUP allTaPW TPUOT4PN 9q1 UIOag paAiaoaa sP14 4T
93UP-4sissP pup uoi4Paad000 9144 S94PT09addP sdao0 9141 : asuo Sgh
' SISQ aqq
uz uOT4OVgST4PS ano oq passgappp uaaq 9AP14 S90anos9a
asagq uo s4opdurT asaanpp aonpaa o4 SaAz4Puaa4TP pup
A4TTzgisuodsaa P sapaq S3WN aqq goT14M aosaOanosag :4uaunuo0
90TAIGS S9TaagSTJ auTaPW TPUOT4PN '20-d9WW00 30 IN3W12iXd3Q 'S'n (C)
• SIa-d 9q4 go t pup
T SUOT409S UT appw uaaq 9APq SUOTSTA9a 94STadoaddv : asuods�aU
' 8E 'b
gdpabpapd uT PapnTOui aq PTnogs (a) L£ 'b 04 ZpTTurTs
gdPabpaPd P 'PaPzPq p 4Ou ATaP9TO ST uotsoaa ssaTun :4uaunuo0
Comment: Once the diversion tunnel is constructed, the Sheld-
rake River channel downstream of Fenimore Road will
be used to collect local runoff. The draft EIS ack-
nowledges that stagnant conditions could develop but
does not offer mitigation measures . We recommend that
in order to avoid mosquito problems and vector-borne
diseases , the area be graded to allow proper drainage
and flushing.
Response: These measures will be implemented.
Comment: The draft EIS states on page 44 that only one bank
along the upper Mamaroneck River will be excavated.
However, Figure 3 of the EIS shows that both banks
will be excavated along the entire stretch of the
river. The final EIS should clarify this discrepancy .
Response : Only the left bank (Town of Harrison side) would be
excavated. Excavation on the right bank would take
place only on the stream side of the existing wall,
so that the existing wall would remain and the trees ,
vegetation, and resident backyards would be preserved.
Comment: The only maps in the draft EIS depict the proposed
alternative, Plan A, making it difficult to determine
the extent of the other plans being considered. Also
the areas currently affected by 100 or 200 year fre-
quency floods are not identified. The Final EIS
should correct these deficiencies .
Response: Descriptions of the various alternatives considered
for detailed analysis are presented in Section 6 and
Tables 11, 12, 13 and 14 of the Revised EIS . Addi-
tional information is presented in the Feasibility
Report.
Comment: In accordance with EPA policy, we have rated this
draft EIS as ER-2 indicating that we have environmental
reservations concerning the project' s potential im-
pacts on water quality (ER) and that we have requested
additional information in order to complete our re-
view (2) .
(5) U.S. DEPARTMENT OF HEALTH, EDUCATION AND WELFARE, Region II
Comment: Based upon our review of the DEIS, we have determined
that those impacts of concern to this Department have
been adequately addressed.
(6) U.S. DEPARTMENT OF THE INTERIOR, Bureau of Outdoor Recreation
Comment: No comments will be provided at this time.
77
(7) U.S. DEPARTMENT OF THE INTERIOR, Fish and Wildlife Service
Comment: In general, we believe the statement adequately de-
scribes the project ' s impact on fish and wildlife re-
sources, however, we wish to provide the following
comments to assist you in the preparation of the final
statement.
Comment: The sentence on page 38, paragraph 4 . 20 , which reads
"Breeding and spawning of fish could result if con-
struction occurs during spawning is incorrect and
should be deleted.
Response: Paragraph 4. 21 has been revised.
Comment: Minnows, shiners, and the American eel are found in
the Byram River despite the degraded water quality
and should be mentioned in the final statement.
Response: The Revised EIS makes note of this information.
Comment: Again, in Paragraph 4. 21, line 16 is incorrect as
stated and should be corrected or deleted from the
context.
Response : The errors in this paragraph have been corrected.
(8) U.S. DEPARTMENT OF THE INTERIOR, National Park Service
Comment: We are pleased to note the consideration given to
cultural resources in the DEIS . We would expect to
see the commentaries from both the State Historic
Preservation Officers of Connecticut and New York and
also from the State Archaeologist displayed in the
FEIS .
Response: Copies of the coordination letters are attached.
78
(9) U.S. DEPARTMENT OF TRANSPORTATION, Coast Guard
Comment: As noted in paragraphs 1. 08 and 4. 28 of the subject
DEIS, several bridge crossings in these rivers are to
be altered or replaced. Upon completion of a naviga-
bility determination you will be notified as to whether
or not bridge permits will be required for the describ-
ed bridge construction.
Response: All required coordination with your office will be
effected.
Comment: Paragraph 1. 04 states that the development of water
supply resources within the basin was not a planning
objective because the local communities had abandoned
existing facilities for more economical New York City
water. In view of the City' s proposed tunnel project
to use Hudson River water, it may be appropriate to
reassess the potential of existing supplies in West-
chester County.
Response: Your statement is incorrect. The local communities have not en-
tirely abandoned these existing facilities . The reservoirs
located upstream of the project area are being maintain-
ed on a standby basis. The implementation of the pro-
posed flood control works would not adversely impact on
these reservoirs.
Comment: Groundwater hydrology in the vicinity of the channel
dredging should be described to determine if the
dredging will intersect the water table aquifer and
possibly contaminate the groundwater or affect aquifer
recharge.
Response: The channel excavations required will be on the aver-
age of 2 to 5 feet below existing surfaces . At these
levels borings indicate that only silt, gravel, sand
or bedrock material would be encountered.
Comment: The potential ecological impacts of the project on
Mamaroneck and Port Chester Harbor should be evaluated.
In particular, the statement should discuss the effect
on the aquatic food chain in the harbors of reducing
a primary food source supplied by the River and the
impacts to both harbors of reduced dissolved oxygen
levels and higher water temperatures .
79
Response : Additional information on the effects anticipated due
to dredging in Mamaroneck Harbor is contained in the
Revised EIS. We would like to point out, however,
that it is not clear which primary food sources would
be significantly reduced by channelization. No high-
ly productive lands such as saltwater marsh or fresh-
water wetland areas are located within or adjacent to
the project areas. It is also not clear as to what
basis of information the Coast Guard expects increases
in water temperatures and decreased dissolved oxygen
levels for the harbors .
Comment: The impact of introducing a new freshwater flow on
the salinity and the aquatic ecology in general of the
West Basin should be evaluated. Paragraph 4 . 23 should
quantify the flow volumes into the basin with and with-
out the diversion tunnel.
Response: Additional information is presented in the REIS .
Comment: The impacts on the East Basin concerning changes in
stream flow volume, velocity and hydrographic charac-
teristics should also be discussed.
Response: Under the 100 year storm conditions , approximately
1, 878 cfs would be diverted from the Mamaroneck River,
decreasing the extent of channel work required on the
lower Sheldrake and lower Mamaroneck River project
areas. Under normal daily flows, an average of 17 cfs
would be diverted, should the tunnel plan be imple-
mented.
80
(10) U.S. DEPARTMENT OF TRANSPORTATION, Federal Highway Administration
Comment: Construction plans should be submitted to this office
for review and approval in lcoations where highways on
the Federal aid system would be affected.
Response: This coordination will be effected.
Comment: Possible effects of the proposed Mamaroneck River
channel work on the bridges carrying First Street
and the Boston Post Road over the Mamaroneck River
must also be considered.
Response: The plans under consideration provide for riprap
along the modified channel in areas where high veloc-
ities might induce erosion, and at each of the bridges .
(11) NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION, Office
of Environmental Analysis
Comment: We have reviewed the DEIS and do not have any comments
on the statement. Since we are involved as a non-
Federal interest in the proposal, we will review addi-
tional information as it becomes available and specific
plans are developed.
Comment: Thank you for the opportunity to review this statement.
We would like to receive three copies of the Final EIS
when it is available.
Response: This coordination with your office will be effected.
(12) STATE OF CONNECTICUT, DEPARTMENT OF ENVIRONMENTAL PROTECTION
Comment: Through ongoing coordination, the Connecticut Depart-
ment of Environmental Protection has been involved
with the Corps of Engineers in formulation of a plan
to reduce chronic flooding of the Byram River in the
Town of Greenwich. We feel that the recommended pro-
posal as outlined in the Draft Environmental Statement
is the most effective alternative among those studied
and we encourage its implementation.
Response: We thank your office for its cooperation and assist-
ance given the Corps . As plans are more fully de-
veloped our coordination with your office will con-
tinue.
81
Comment: Despite D.E.P. 's endorsement of the flood control pro-
ject as proposed, we feel that in a number of areas
inadequate documentation has been given its environ-
mental impacts in the Draft Environmental Statement.
Where noted, further substantiation and additional data
would present a more accurate description of the ex-
isting environmental conditions, the project ' s impact
and the range of practical mitigation measures . More
specific comments on the Environmental Statement are
attached.
Comment: The Corps of Engineers proposes a number of mitiga-
tion measures for the Byram River project which we
endorse. We request that DEP be provided with the
final Byram River design plans for review and comment,
to insure that all feasible measures are taken to
eliminate or reduce adverse impacts .
Response : This coordination will be effected.
Comment: The format of the Draft Statement is confusing. A
more legible format would be completely separate dis-
cussions and evaluations of the Byram River Basin and
Mamaroneck and Sheldrake Rivers Basin project.
Response: Each project is described under separate headings .
Much of the material presented in the EIS , however ,
is applicable to each project.
Comment: Much of the quantitative data on chemical, physical ,
and biological parameters, on which numerous assump-
tions and conclusions are based, is absent from the
statement. Lack of such data prevents D.E.P . from
verifying or concurring with statements regarding the
degree of impact the proposed project will have on
the Town of Greenwich.
Response: Additional information has been included in the Revis-
ed EIS (refer to Tables 8 and 9) .
Comment: In paragraph 1. 17, the benefit-cost ratio of 1. 7 con-
flicts with the figure given in Table 1.
Response: This error has been corrected.
Comment: A claim for sufficient water supply for present and
future needs in Southwestern Connecticut is neither
documented nor referenced (paragraph 2.29).
Response : We refer to a 1973 report by the Connecticut Office .
of State Planning entitled Proposed: A Plan of
Conservation and Development for Connecticut. Accord-
ing to this report, the present water resources of
the State, including both developed and undeveloped
facilities were projected as being adequate to supply
82
an estimated population of 4. 9 million by the year
2, 000 . Specific recommendations were made for the de-
velopment of new reservoirs and groundwater facilities .
A total of ninety-one sites were identified. None of
these potentially productive sites are in the Town of
Greenwich.
Comment: The water quality classifications for Connecticut
waters, and the Byram River, were revised in 1976.
Response: We understand that proposed revisions were initiated
in November of 1976 and that these new classifications
would become effective in December of 1977. The EIS
has been revised accordingly.
Comment: Municipal sewage discharges from the Town of Port
Chester will _e eliminated in the near future.
Response: It is correct that the present primary treatment faci-
lity at Port Chester will be upgraded and sewage would
would be pumped to nearby Blind Brook. However, these
plans have not yet been funded.
Comment: Some species listed in paragraph 2. 37 are omitted from
Appendix A - the Biological Inventory. If marsh plants
are present, then inland wetland parameters need be in-
vestigated.
Response: Wetlands are present within the Byram River Basin.
However, no significant wetlands are present in the
flood project area.
Comment: In paragraph 2. 51, the lack of aesthetic features
cited here conflicts with Section 2. 37, in which a
pleasant aesthetic character is noted.
Response: There is no conflict when taken within the context of
paragraphs 2. 50, 2. 51 and 2. 37 . (Note the numbers of
these paragraphs have been revised to 2. 42, 2. 56 and
2. 57, respectively) .
Comment: No assessment of the chemical character of proposed
dredge spoils is provided (paragraph 3. 07) . Given the
existing water quality in the Byram River, it is
possible that any dredged sediments will be polluted.
Land disposal of such sediments should be evaluated.
Response: The suitability of dredged material for construction
of levees or for the placement of fill would be deter-
mined during the detailed design planning stages . Any
material found unsuitable for such uses would be de-
posited at approved dump sites after coordination with
the applicable federal or local agencies. (Refer also
to Tables 8 and 9 of the REIS) .
83
Comment: In paragraph 4. 06 the discussion of sedimentation im-
pacts is general. No effort is made to tie the erosion
and sedimentation potential to specific soil types
mentioned in 2. 23 .
Response: At this stage of the investigation, it is not possible
to accurately predict the extent of erosion and sedi-
mentation problems, should the proposed project be
constructed. We believe that adverse effects due to
increases in erosion and sedimentation would be tem-
porary occurring primarily during the construction
period. As stated in the EIS the Corps is committed
to certain mitigation measures which would minimize
such adverse effects. (refer also to paragraph 4 . 05)
Comments : The discussion in paragraph 4. 09, on water quality
impacts is somewhat speculative. Absence of hydro-
logic data, both existing and projected, prevents us
from evaluating the projects impact on water quality
to our satisfaction.
Response: Additional information on the hydrology and hy-
draulics of the Proposed Project is presented in
Appendices A and B of the Feasibility Report, and in
Table 7 of the REIS.
Comment: If construction occurs during spawning periods (para-
graph 4-20) spawning and breeding will be severely
hindered, rather than promoted.
Response : This error in the text has been corrected.
Comment: In paragraph 4-20, there is no indication of the height
of the proposed sill at the mouth of Pemberwick Lake .
Response: The height of the proposed sill at the mouth of the
Pemberwick is approximately 3 feet. The top of the
sill would approximate elevation of the existing
stream bottom at this location.
Comment: Mitigation measures, including installation of a low
flow meander channel and gabbion wire baskets , are
strongly encouraged, (Paragraphs 4. 34-4. 38) . If the
Pemberwick Lake sill is a barrier to fish, we recom-
mend that design be modified to eliminate that barrier
or provide a means to allow free passage of fish a-
round that barrier. We request the opportunity to
review design plans to assure that adequate mitigation
measures are undertaken.
Response: The Corps of Engineers is committed to providing
justifiable measures which would mitigate adverse
project impacts . The proposed sill is designed to
preserve Pemberwick Lake by maintaining the water
level at its present elevation. However, because of
the limited fishery resources present in the Byram
river additional mitigation measures may not be in-
cluded without adequate justification. As mentioned
previously, our coordination with your office will
continue as plans become further detailed.
84
Comment: A numerical value for the Standard Project Flood
would be appropriate (Paragraph 6. 03) .
Response: The Standard Project Flood along the Byram River at
Greenwich and Port Chester is 13,250 cubic feet per
second.
Comment: Inadequate discussions are given in paragraphs 7. 01
8 . 01 to biological productivity and aesthetics . With
additional data on stream flow, water quality and
biological parameters it will be possible to expand
the evaluation of long-term productivity.
Response: The assessment of the environmental impacts as they
are related to the proposed project have been stated
in Sections 4, 6, 7 and 8 of the EIS . Since as men-
tioned previously the project area has been urbanized
and such relatively productive areas such as salt marsh
or freshwater wetlands areas would not be affected,
additional detailed discussions of water quality,
stream flow or biological parameters are not required.
Comment: The biological inventory contains numerous spelling
and nomenclature errors . The list appears to include
all species which could conceivably be found in the
project area. A more accurate representation of the
flora and fauna would be based on actual observation.
Response : The various typographical errors have been corrected
in the Revised EIS . Much of the information provided
in the inventory is based on actual observations.
However, there are several difficulties in presenting
such information accurately and fairly. With regard
to the flora, both project areas are located in an ur-
ban setting. Many of the plant species present are
located on the properties of the local residences and
are not native to the area but rather consist of orna-
mental trees or shrubs. As mentioned in the EIS ,
there are relatively less disturbed sections of vege-
tation along the streambanks , but these areas also
have been impacted by urbanization. The predominant
forms present in the Byram River Project area are
common to river corridor or flood plain areas of this
type and are in fact listed in the EIS. With regard
to the animal species mentioned in paragraph 2. 33 and
2. 40, and the Appendix, the species indicated are
known to exist in the project area or within the
basin-wide area and, therefore, some of these species
particularly those with the wider feeding ranges could
conceivable utilize the remaining habitat within the
given project area or the surrounding region.
Comment: Reference should be made to "Rare and Endangered
Species of Connecticut and Their Habitats . " Many of
the species listed in the Appendix are rare and en-
dangered in Connecticut, yet no mention is made of
this status , or the project' s impact on rare and en-
dangered species .
85
Response : The above report as well as the United States threat-
ened and endangered species lists were checked. As
mentioned in the EIS, only the U. S . endangered species ,
the American peregrine falcon and the U.S . threatened
species , the American osprey (state endangered) have
been observed within the Town of Greenwich. Based on
our present knowledge, habitat critical for endangered
or threatened species (federal or state species) is
not present in the project areas. If your office is
aware of any additional information regarding this sub-
ject, then we request that coordination be effected
with our office.
(13) TOWN OF GREENWICH, CONNECTICUT, Inland Wetlands and Water
Courses Agency.
Comment: In developing the cost-benefit ratio, for the NED and
EQ-Plans it was unclear how the various figures were
arrived at. A more detailed breakdown of the costs
and benefits is required. In addition, a discussion
of the estimated flood losses for the June 1972 flood
should be specified.
Response: Detailed estimates of the benefits and costs , and the
economic analyses, are contained in Appendices D and E
of the project Feasibility Report. All estimates are
based on December 1976 price levels . Cost estimates
are based on work quantities developed from plan lay-
outs and cross-sections in conjunction with unit prices
for each item. First costs include the charges aris-
ing from the construction of the project, including
costs of contingencies, engineering, design, supervision
and administration and overhead. Estimates of flood
control damages on the Byram River basin are based
on flood damage surveys made by the Corps of Engineers
in connection with previous flood control reports , a
survey made in 1956 to determine flood damages from
the flood of October 1955, and more recent surveys
made in 1971, 1972, and 1975.
Comment: The fish and wildlife habitat evaluation within the
study area is deficient. In addition to being exceed-
ingly brief, the fish, vegetation, wildlife and habitat
surveys appear to have been generated from a literature
search rather than actual field survey. If field sur-
veys were completed, the number of days spent surveying
the study area as well as the qualifications of those
who completed the survey should be indicated.
Response: The biological resources data for the Byram Project
area was compiled from a literature search, coordina-
tion with the U.S. Fish and Wildlife Service, the U.S .
Environmental Protection Agency and the Connecticut
Department of Environmental Protection and by field in-
vestigations performed by Corps biologists and engineers .
86
Comment: Numerous times in the statement, fish, wildlife and
vegetation/habitat resources were described as marginal
without any real documented justification. For such
a highly developed urban area, sections of the project
area are in an extremely viable state when compared
to other rivers in the area.
Response: When comparing the remaining habitat areas within the
project area to other areas within the basin, par-
ticularly upstream, the resources present must be con-
sidered marginal. The lower project areas as de-
scribed in the DEIS, has been developed by local com-
merce and industry. The upper project area is entire-
ly residential. Most of the "habitat resources" are
in fact located in the backyards of these residences .
Comment: The statement does a good job in evaluating the ad-
verse impacts associated with NED Plan. In essence,
the report revealed that the entire natural, riverine/
flood plain habitat within the project area will be
destroyed. In addition, it was clear that regular
maintenance of the improved channel would severely
limit the reestablishment of normal aquatic habitats .
in fact, regular channel maintenance could have as
severe adverse impacts as the actual construction
activities.
Response: As described in paragraph 4 . 23 of the REIS, a total of
about 3 acres of vegetation and wildlife habitat would
be eliminated. No construction works would be imple-
mented along the west bank of Pemberwick Lake. A
limited shrub and tree planting program and other
mitigation measures would be implemented in order to
minimize adverse impacts . The maintenance of the pro-
posed works would be a local responsibility. The
maintenance work performed would still be subject to
all applicable Federal or local regulations .
Comment: Numerous recommendations were made to mitigate adverse
environmental impacts associated with the NED Plan.
At the minimum, all these recommendations should be
required for any flood control plan that is imple-
mented.
Response: The mitigation measures as described in the EIS would
be implemented.
Comment: More attention in the final EIS should be given to the
study of alternatives. An unsubstantiated statement
is made that upstream flood detention is not a prac-
ticable solution to the flooding problem. Although
there may not be enough flood detention area avail-
able in the Byram River watershed to solve the entire
flooding problem, it appears that there are signifi-
cant undeveloped flood storage areas. A detailed
analysis should be made of detention areas within the
87
watershed in both New York and Connecticut. Such a
study could reveal that as much as 15 to 20% of 100
year stormwater runoff could be detained thus reduc-
ing the 100 year flood elevations with the project
area.
Response : The possibility of utilizing flood detention measures
along the Byram River were investigated early in the
planning process. The incremental flows generated
by local runoff downstream of any potential site -
would still result in flooding at the Greenwich-Port
Chester damage area. Although the 100 year flood
discharges at the study area may be reduced, local
protection works would still be necessary to provide
protection against the 100 year event. The high
costs associated with local protection works in com-
bination with an upstream dam and reservoir clearly
cannot be supported by the flood damage reduction
benefits to be gained at the Greenwich-Port Chester
study area. Additionally, upstream flood detention
basins would not alleviate tidal flooding . After
reservoir considerations were precluded, it became
evident that because of the physical characteristics
of the watershed and the location of the damage
areas, flood protection could best be achieved by
local protection measures .
Comment: All filling within inland wetland, water course and
flood plain areas within the Greenwich Connecticut
sections of the Byram River watershed are regulated
by local ordinance. This regulation limits the
amount of development, preserves flood storage areas
and significantly reduces future increases in storm
runoff rates within the watershed. The EIS should
review the land use patterns of wetlands in N.Y.
State. Are the filling/destruction of wetlands and
flood storage areas being regulated in New York? If
not, what would be the impact of increased runoff/
rates on the lower Byram River resulting from wet-
lands filling in New York?
Response: The Corps of Engineers , and the States of New York
and Connecticut have regulatory authority concerning
construction activities in waterways and wetlands .
No significant salt water, marsh or freshwater wet-
land resources , however, are located within the Byram
River Project area.
Comment: The draft statement indicated that the Environmental
Quality Plan met the planning objectives and maximized
the preservation of the existing stream environment.
The discussion leading to the selection of the NED Plan
considered mainly economic factors without really
assessing the environmental costs. The loss of a very
viable wetland/water course/wildlife corridor, a price-
less community asset, can never be replaced.
88
Response: A complete discussion of the economic, environmental ,
social, and other factors considered in the formula-
tion of alternative plans is contained in Appendix F
of the Feasibility Report and in Section 6 of the EIS .
Comment: The project area could serve as a river park in one
of the most heavily developed areas of Greenwich,
Connecticut and Port Chester, New York. No cost fig-
ures have been included to indicate the loss of this
River Park.
Response: Undoubtedly, such alternate uses are possible, how-
ever, the Land Use Plan developed for the Town of
Greenwich does not indicate that this area is being
considered for use as a river park. The formation
of such a hypothetical park would not alleviate the
flood damages occurring in the study area. Access to
such a park would also require permanent easements
from local homes or businesses .
Comment: The NED Plan requires periodic maintenance of the
channel and other unspecified costs. It would appear
that the periodic maintenance costs for the EQ Plan
would be significantly less because of the absence of
channel improvements yet these savings don' t appear
to have been included in the economic evaluation of
the two plans.
Response: Annual operation and maintenance costs for the NED
and EQ plans are estimated at $20 , 000 , and $14, 700 ,
respectively for the Byram River Project. A large
part of these costs is for the operations and main-
tenance of the pumping stations included in both
plans , and the levee and floodwall features common to
both plans, however, it should be noted the levee and
floodwall works for the EQ Plan are more extensive
than the works required in the NED plan.
Comment: Finally, additional discussion of the EQ Plan should be
included within the final E.I.S . This discussion
should review the environmental advantages of the plan,
steps necessary to minimize adverse impacts associated
with the plan, and an EQ Plan drawing similar to figure
#6 .
Response: As mentioned previously, a complete discussion of the various
alternative plans considered during plan formulation is contained
in Appendix F of the Feasibility Report and in Section 6 of the
REIS.
89
9.05 Comments Received as a Result of Departmental Review.
(1) U.S. Department of Agriculture, Office of the Secretary.
Comment: Although it is recognized that agricultural pursuits in these
basins are minimal, housing and other development activities
with their associated land disturbances can create a potential
for erosion and sediment problems. These can impact the effec-
tiveness of the measures proposed under this program. The West-
chester (New York) and Fairfield (Connecticut) County Soil and
Water Conservation Districts have the capability to furnish
technical assistance to land users and developers. It may be
worthwhile to consider conducting an accelerated program to fur-
nish technical assistance to these land users. The statement
should address the potential for this impact.
Response: As stated in Section 3 of the EIS, both study areas are loca-
ted in essentially fully developed areas . In addition, Para-
graphs 3.04-3.06 provide a discussion concerning future develop-
ment within the flood-plain.
(2) U.S. Environmental Protection Agency, Region II
Comment: We have no objection to the proposed project, provided that the
recommendations made by the U.S. Fish and Wildlife Service in
the Fish and Wildlife Coordination Act Report are complied with.
The final EIS should discuss this report and how its recommen-
dations will be implemented.
Response: The various mitigation measures listed in pages 7 and 8 of the
environmental statement were developed, in part, from coordina-
tion with the U.S. Fish and Wildlife Service. We must note,
however, that certain of the mitigation measures recommended
by the Fish and Wildlife Service are not consistant with solving
flood control problems of the area in the most economical manner.
This office will continue to coordinate with the Fish and Wildlife
Service in order to resolve this matter. In addition, please also
note that we have included a copy of the final F & WCA report in
Appendix F of this statement, along with a copy of our recent
reply.
90
Comment: In accordance with EPA procedures we have rated the revised
draft EIS as category LO-2, indicating that we lack objections
over the proposed project (LO) and that more information is
needed before we make a final determination (2) .
Response: Your comment is noted.
(3) U.S. Department of Health, Education, and Welfare, Center for Disease
Control.
Comment: No foreseeable adverse health effects were noted in this state-
ment. However, it is possible that the drop structure could
become a breeding site for black flies , which can be aggravating
pests to both humans and livestock, but not known to be disease
vectors in the United States.
Response: Black flies are not known to be a problem within Westchester
County, New York. However, this office will coordinate with
the State Department of Health, as you requested.
(4) U.S. Department of Housing and Urban Development, Hartford Area Office.
Comment: Our review of the Impact Statement was confined to the effect
the flood control project would have on any existing or pro-
posed programs this agency is or contemplates assisting. Since
there does not appear to be any such assistance at this time
we have no comments to offer.
Response: Your comments are noted.
(5) U.S. Department of the Interior, Office of the Secretary
Comment: We have completed our review of the revised draft environmental
statement for this proposal. The statement contains an adequate
discussion of the project's impacts on our areas of jurisdic-
tion and/or special expertise. However, we do believe that the
statement would be improved by the adoption of the recommenda-
tions to reduce the adverse impacts on the fish and wildlife
resource base.
Response: The various project mitigation measures that are proposed by the
Corps of Engineers to reduce adverse impacts on the fish and wild-
life resource base are listed on pages 7 and 8 of the Final EIS.
The mitigation measures include may of the recommendations cited
by the F & WS regional office. However, it should be noted that
certain of the mitigation measures recommended by the Fish and
Wildlife Service are not consistant with solving the flood control
problems of the area in the most economical manner. This office
will continue its coordination with the Department of Interior
and will consider all of the final F & WCA report's recommendations
during the detailed planning stages of this study. For your infor-
mation, we have included a copy of your report, along with our re-
ply in Appendix F of this impact statement.
91
(6) New York State, Department of Environmental Conservation, Office of
Environmental Analysis.
Continent: The Department of Environmental Conservation has completed
its review of the above noted document and has no comments to
offer at this time.
Response: Your comment is noted.
(7) State of Connecticut, Department of Environmental Protection, Commissioner.
Comment: The one concern of this department is to see that environmental
considerations for fish restoration are incorporated into the
final design of channel modification for the Byram River through
Greenwich, Connecticut.
Response: Mitigation measures for the Byram River project are presented
on page 8 of the FEIS. The Corps of Engineers will continue
to maintain coordination with your office as these plans become
further detailed.
• 92
APPENDIX A
LETTERS RECEIVED BY THE
CORPS OF ENGINEERS AS A
RESULT OF COORDINATION OF THE
DRAFT ENVIRONMENTAL IMPACT STATEMENT
UNITED STATES DEPARTMENT OF AGRICULTURE
FOREST SERVICE
NORTHEASTERN AREA. STATE AND PRIVATE FORESTRY
6816 MARKET STREET. UPPER DARBY. PA. 19062
(215) 596-1671
6420
March 10 , 1977
Mr. J. A. Weiss
Chief, Engineering Division
Department of the Army
New York District, Corps of Engineers
26 Federal Plaza
New York, New York 10007
Refer to : NANEN-E , Draft
Environmental Statement, Flood
Control , Mamaroneck, Sheldrake
and Byram Rivers , CT & NY
Dear Mr. Weiss :
The effects of maintenance on water quality (p. 35-36) and
other environmental factors are not clearly described for
reviewers who did not participate in the program. There
is no mention of sediment produced during maintenance.
Removal of vegetation, especially if it involves complete
uprooting, will cause significant erosion and increase in
sedimentation. Proper species selection, timing, and
planting procedures for reestablishing streambank vegetation
would help mitigate such effects . Sowed and planted vegeta-
tion will need to be monitored to ensure that it becomes
stabilized. Mulches may be needed on some sites .
We could understand the impacts of the project more readily
if some portions were clarified - paragraph 4 . 20 , in
particular. The sentence on lines 4 and 5 is unclear, and
the sentence on lines 16 to 20 is muddled.
Thank you for the opportunity to review this Draft Statement.
Sincerely, �-
i
DATE 0. VANDENBII ,
Staff Director
Environmental Quality Evaluation
Al
UNITED STATES DEPARTMENT OF AGRICULTURE
SOIL CONSERVATION SERVICE
Rm. 771, U. S . Courthouse & Federal Bldg. , 100 So. Clinton St. , Syracuse, N.Y.
13202
January 24, 1977
Mr. J. A. Weiss , Chief
Engineering Division
Department of the Army "
New York District Corps of Engineers
26 Federal Plaza
New York, N. Y. 10007
Dear Mr. Weiss :
We have reviewed the draft of the Environmental Statement for the Flood
Control Project for Mamaroneck & Sheldrake Rivers Basin (Village and Town
of Mamaroneck, N.Y.) and for Byram River Basin (Greenwich, Conn. and
Port Chester, N.Y.) , prepared by the U. S. Army Engineer District,
New York, N. Y. dated January 1977.
We submit the following comments :
1. From the description of the works of environment, it would appear that
the project would have minimal effect on prime and unique farm lands .
The statement would be improved by clearly stating whether or not prime
and unique farm land will be impacted by the project.
2. Paragraph 3.07 "Land Acquisitions & Spoil Disposal" . This paragraph
could be improved by stating "usable topsoil will be salvaged, protected
and reused in construction. The last sentence might state, "Excess
spoil material generated will be stabilized and protected from erosion".
3 . Paragraph 4.09, page 35, "Water Quality" . The last complete sentence
on this page seems to say, "denuded channel banks will be a problem
until the banks revegetate and stabilize themselves". This should be
reworded to state that the banks denuded, as a result of project
construction, will be revegetated and stabilized as a part of the
construction measures .
4. paragraph 4.38 "Byram River". Unless erosion is clearly not a hazard,
a paragraph similar to 4.37(e) should be included under this paragraph.
We appreciate the opportunity to review and comment on this proposal.
Sincerely,
Robert L. Hilliard,
State Conservationist. A2
cc : R. M. Davis , Administrator, SCS , Washington, D.C .
Dr . Fowden G. Maxwell, Coordinator, Office of Environmental
Quality Activities , Office of Sec'y., USDA, Washinplton, D.
Council on Env. Quality, Washington,D.C . Attn: Genera Counse
U.S. DEPARTMENT O. COMMERCE
National Oceanic and Atmospheric Administration
NATIONAL MARINE FISHERIES SERVICE
Federal Building, 14 Elm Street
Gloucester, Massachusetts 01930
February 1, 1977
Col. Thomas C. Hunter, Jr.
District Engineer
Department of the Army
Corps of Engineers
26 Federal Plaza
New York, New York 10007
Dear Colonel Hunter:
The National Marine Fisheries Service has reviewed the Draft Environmental
Impact Statement for the Flood Control Project for Mamaroneck and Shel-
drake Rivers Basin (Village and Town of Mamaroneck, New York) and for
Byram River Basin (Greenwich, Connecticut and Port Chester, New York) .
In order to provide as timely a response to your request for comments
as possible, we are submitting the enclosed comments to you directly, in
parallel with their transmittal to the Department of Commerce for incorpora-
tion in the Departmental response. These comments represent the views of
the National Marine Fisheries Service. The formal, consolidated views
of the Department should reach you shortly.
Sincerely yours,e___
William G. Gordon
Regional Director
Enclosure
�O�UT oti A3
6 2
�b ?
��fi t9'6^a
�= U.S. DEPARTMENT = COMMERCE
,�. National Oceanic an_ Atmospheric Administration
• NATIC'VAL NIAR 'JE FISHERIES SERVICE
Federal Building, 14 Elm Street
Gloucester, Massachusetts 01930
DATE: February 1 , 1977
TO: Director, Office of Ecology and Environ-mental Conscrvation, EE
THRU: Acting Assistant Director for Scientific and Technical Services, FS
.)
FROM: Regional Director, FNE wedAk'W" F fsoussc,
SUBJECT: Draft Environmental Impact Statement -- (Flood Control Project for
Mamaroneck and Sheldrake Rivers Basin, Village and Town of
Mamaroneck, NY and for Byram River Basin, Greenwich, CT and Port
Chester, NY) -- (CE)
The National Marine Fisheries Service was consulted during the planning
stages of the proposed project or during development of the DEIS. Resources
for which NMFS bears a responsibility and alternatives to reduce adverse
impacts on these resources have been addressed to our satisfaction in the
DEIS. Therefore, we have no comments.
FMLudwig/djh
cc: F53(3)
FNE
Milford EAB
tf0 3t4,�a
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION II
26 FEDERAL PLAZA
NEW YORK. NEW YORK 10007
14 MAR 1977 Class. ER-2
Mr. J. A. Weiss
Chief, Engineering Division
New York District, Corps of Engineers
26 Federal Plaza
New York, New York 10007
Dear Mr. Weiss :
We have reviewed the draft environmental impact statement (EIS) for the
Flood Control Project for the Mamaroneck and Sheldrake Rivers Basin in
the Village and Town of Mamaroneck, Westchester County, New York and
for the Byram River Basin in the Village of Port Chester, Westchester
County, New York and the Town of Greenwich, Fairfield County, Connecticut.
The proposed project consists of the installation of flood control works
which include river widening and deepening, levee and retaining wall
construction, river diversion and bridge reconstruction. The following
comments are offered for your consideration in preparing the final EIS.
Larchmont Gardens Lake, located downstream of the proposed works on the
Sheldrake River will act as a sediment trap unless proper mitigating
measures are taken. Organisms which survive the sedimentation would
probably be destroyed by dredging operations necessitated by accelerated
sediment deposition. We recommend that silt screens and/or other sedi-
ment control devices be incorporated into the construction plans in
order to mitigate this adverse impact.
The draft EIS indicates that the sediments produced from the widening
and dredging of the rivers will be used in the construction of the
levees. However, the suitability of the dredged material for this
purpose has not yet been determined. The final EIS should discuss the
suitability of the dredge material for levee construction, and if the
material is found to be unacceptable, it should indicate how the material
would be disposed and how the purchase of needed material would affect
project costs.
The West Basin of Mamaroneck Harbor will be dredged to handle the extra
water that would be directed there from the Sheldrake River diversion
tunnel . The final EIS should identify where this dredged material will
be placed and what effect the dredging will have on the harbor.
AS
2
Once the diversion tunnel is constructed, the Sheldrake River channel
downstream of Fenimore Road will be used to collect local runoff. The
draft EIS acknowledges that stagnant conditions could develop but does
not offer mitigating measures . We recommend that in order to avoid
mosquito problems and vector-borne diseases , the area be graded to
allow proper drainage and flushing.
The draft EIS states on page 44 that only one bank along the upper
Mamaroneck River will be excavated. However, Figure 3 of the EIS shows
that both banks will be excavated along the entire stretch of the river.
The final EIS should clarify this discrepancy.
The only maps in the draft EIS depict the proposed alternative, Plan A,
making it difficult to determine the extent of the other plans being
considered. Also, the areas currently affected by 100- or 200-year
frequency floods, as well as Columbus Park and other recreational
resources mentioned in the draft EIS are not identified. The final
EIS should correct these deficiencies.
In accordance with EPA policy, we have rated this draft EIS as ER-2
indicating that we have environmental reservations concerning the
project's potential impacts on water quality (ER) and that we have
requested additional information in order to complete our review (2) .
If you have any questions concerning this letter, please feel free to
contact this office at 264-8556.
Two copies of the final EIS are requested for subsequent review.
Sincerely yours ,Li
Barbara M. Metzger
Chief
Environmental Impacts Branch
Asa
H1H [U,
DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
REGION 11
,' s• FEDERAL BUILDING
26 FEDERAL PLAZA
NEW YORK, NEW YORK 10007
OFFICE OF THE
REGIONAL DIRECTOR
February 18, 1977
Mr. J.A. Weiss
Chief, Engineering Division
Department of the Army
New York District Corps of Engineers
26 Federal Plaza - Room 2143
New York, New York 10007
Subject: Draft EIS #003-1-77
Flood Control Project for Mamarneck, Sheldrake and Byram River
Basins
Dear Mr. Weiss:
Based upon our review of the subject Draft EIS, we have determined that
those impacts of concern to this Department have been adequately addressed.
Sincerely yours,
Luther W. Stringham
Regional Environmental Officer
A6
E'" or r
-- _ United States Department of the Interior
BUREAU OF OUTDOOR RECREATION
NORTHEAST REGIONAL OFFICE
Federal Building • Room 9310
IM RZVLY eiRa To: 600 ARCH STREET
4120 Philadelphia, Pennsylvania 19106
F 1 10 r
Mr. J. A. Weiss _
Chief, Engineering Division
Department of the Army
New York District, Corps of Engineers
26 Federal Plaza
New York, NY 10007
Dear Mr. Weiss:
This is in response to a January 14, 1977 letter to the Department
of the Interior, Office of Environmental Project Review, requesting
comments on the draft environmental statement for Flood Control for
Mamaroneck and Sheldrake Rivers, Westchester County, New York and
Byram River, Fairfield County Connecticut. At this time, we are
unable to provide comments because our manpower and funds are
committed to other ongoing activities.
Sincerely yours,
Iss
SJONOGistant Regional Director
JOWTiOH
Q� 6iC�
2 Z
m A7
���g_1916
r yF
O _�A-�•-Z
UNITED STATES
DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE
One Gatewav Gente, S.,Ie'DC
IN REPLY kEFER To: NEWTON CORNER. MASSACHUSETTS 02158
ER-77/61
977
District Engineer
New York District
Corps of Engineers
26 Federal Plaza
New York, NY 10007
Dear Sir:
This responds to your letter of January 14, 1977, requesting our comments
relative to the draft environmental impact statement for Flood Control
for Mamaroneck and Sheldrake Rivers, Westchester County, New York and
Byram River, Fairfield County, Connecticut.
In general, we believe the statement adequately describes the projects'
impact on fish and wildlife resources, however, we wish to provide the
following comments to assist you in the preparation of the final statement.
The sentence on page 38, paragraph 4.20, which reads "Breeding and spawning
of fish could result if construction occurs during spawning" is incorrect
and should be deleted.
The sentence on lines 13 through 16 on the same page which states "For the
Byram River no species were observed, although these species are common
and may also be present there, the degraded water quality of the waterway
makes it unlikely that even these species would be present" is incorrect.
Minnows, shiners, and the American eel are found in the Byram River
despite the degraded water quality and should be mentioned in the final
statement.
Again on page 38, the sentence on line 16 which reads "One potential
adverse effect would be the restoration of these streams to more abundant
levels as fish or wildlife habitats, a possibility which would be further
diminished by alterations to the natural environment by the proposed
channel modification" is incorrect as stated and should be corrected or
deleted from the context. It is somewhat unclear as to what the writer
wishes to convey - stream restoration is not an adverse effect.
The opportunity to review the subject document is appreciated.
Si e 1 1 y yo s,;
�pLUTlp,1,
2 T /
zn`TiNG Regional Director
2
�� ^a A8
EN? O,
United States Department of the Interior
..,..._� ,� :v'ATIONAL PARK SERVICE
Y~�
^b.<. •` NORTH ATLANTIC REGION
150 CAUSEWAY STREET
1% RFPL% REFER TO' BOSTON, MA. 02114
L-7619-NAR-(PE)
ER-77/61 March 4, 1977
Colonel Thomas C. Hunter, Jr.
District Engineer
Department of the Army
New York District
Corps of Engineers
26 Federal Plaza
New York, New York 10007
Dear Colonel Hunter:
Our Departmental Office of Environmental Project Review has
asked that our comments on your draft environmental statement
for Flood Control for Mamaroneck and Sheldrake Rivers, West-
chester County, New York and Byram River, Fairfield County,
Connecticut, be sent directly to you. We understand that a
Departmental commentary will be made later when requested by
the Chief of Engineers.
We are pleased to note the consideration given to cultural
resources in your draft environmental statement. The Corps'
commitment to maintain coordination with the appropriate
State Historic Preservation Offices is good and essential.
We would expect to see the commentaries from both the State
Historic Preservation Officers of Connecticut and New York
and also from the State Archeologist displayed in the final
environmental statement.
Sincerely yours,
Gilbert W. Calhoun
Acting Regional Director
OuuTio,.V
6
A9
� Z
c �
y m
� 2
DEPARTMENT OF TRANSPORTATION
MAILING ADDRESS.
O UNITED STATES COAST GUARD Commander (oan)
Third CC District
Governors Island
Kew York, NY 10004
(212 ) 264-8341
16590
FEB 2 5 1977
From: Commander, Third Coast Guard Distr:: C'
To Chief, Environmental Branch, Corps of Engineers ,
New York District
Subj : DEIS, Flood Control Project, Mamaroneck, Sheldrake,
and Byran River Basins , January 1977
1. As noted in paragraph' s 1. 08 and 4.28 of the subject
DEIS, several bridge crossings in these rivers are to be
altered or replaced. As no information as to the navigable
character of these waterways in the project areas are
presently available, navigability determinations must be
completed to evaluate the extent of the Coast Guard' s
jurisdiction. Upon completion of these studies you will
be notified as to whether or not bridge permits will be
required for the described bridge construction.
2 . Attached are comments on the DEIS from the Third Coast
Guard District Marine Environmental Branch.
W. C. I- MING
By direction
A10
UNITED STATES GOVERNMEN{ DEPARTMENT OF TRANI.PORT ATION
Memorandicfn UNITED STATES COAST GUARD
16475.2/3-77
DATE: 9 February 1977
SUBJECT: DEIS, Flood Control Project, Mamaroneck, Sheldrake and Byram Rivers
Basins, January, 1977
FRom Environmental Protection Specialist
TO Chief, Bridge Section
REF (a) CCCD3(.--,) memo 16475.2/2-77 dtd T1.• „
1. The subject impact statement has been reviewed and the follo;ains
comments are forwarded to your office in accordance with reference (a) .
2. Paragraph 1.04 states that the development of water supply sources
within the subject basin was not a planning objective because the local
' communities had abandoned existing facilities fc�i more economical
New York City water. In view of the City's proposed tunnel project to
use Hudson River water, it may be appropriate to reassess the potential
of existing water supplies in Westchester County.
3. Although potable water in the area is presently supplied by surface
sources (paragraph 2.26) , groundwater hydrology in the vicinity of the
channel dredging should be described to determine if the dredging will
intersect the water table aquifer and possibly contaminate the ground-
water or affect aquifer recharge.
4. The potential ecological impacts of the project on Mamaroneck and
Port Chester Harbors should be evaluated. In particular, the statement
should discuss:
a. The effect or, the aquat_C food C 3i^_ in the harbors of
a primary food source supplied by the rivers;
b. The impact of introducing a new freshwater flow on the salinity
and aquatic ecology in general of ?.Test Basin; paraerapin W' .23
should quantify the flow volumes into the basis, with and without
the diversion tunnel;
c. The impacts on East Basin of a change in stream flow volume, `
velocity and 'hydrographic characteristics;
d. The impacts on both harbors of reduced dissolved oxygen levels
and higher water temperatures.
All
DEPT. OF TRANS', USCG, CG-A913 (3-73)
16475.2/3-77
9 February 1977
SUBJ: DEIS, Flood Control Project, Mamaroneck, Sheldrake and Byram Rivers
Basins, January, 1977
5. It is requested that you forward our comments to the Corps of
Engineers if you are unable to complete your review by 28 February.
R. F. WILDERMANIv
Encl: (1) Subject DEIS
Al2
Of Tg4,,T"r
4/ T
U. E, JEPARTM ENT OF TRANSPORTA . .ON
r FEDERAL HIGHWAY ADMINISTRATION
i REGION ONE
4iNew York Division Office
S (S Q�
Iso W. O'Brian Federal Building, Ninth Floor
Albany, New York 12207
February 1, 1977
-N REPLY REFER TO:
01-36.2
Your ref=rend:
NA N3 N-?
Mr . J. A. Weiss
Chief, 3ngineering Division
Department of the Army
New York District, Corps of 3ngineers
26 Federal Plaza
New York, New York 10007
Subject: DUS, Flood Control Project for Mamaroneck and Sheldrake River
Basin and for Byram River Basin
Dear Mr. Weiss:
Our review of the subject DRIB reveals that work is proposed at the
following locations on the Federal aid system of highways:
Villaga of Mamaroneck
Halstead Ave. over Mamaroneck River - New bridge proposed
Palmer Ave. - Proposed tunnel carrying Sheldrake River under
Boston Post Rd. (U.S.1) - Proposed tunnel carrying Sheldrake River under
Port Chester - Greenwich
U. S. 1 over Byram River - Bridge enlargement proposad
Construction plans for the above work must be submitted to this office
for review and approval.
Possible effects of the proposed Mamaroneck River channel work on tae
bridges carrying First St. arm the Boston Post Road over the Mamaroneck
River must also be considered.
Thank you for this opportunity to comment on this flood control project.
Sincerely yours,
Victor CTay
Division Adminis t
A13
rt
New York State Department of Environmental Conservation
50 Wolf Road, Albany, New York 12233
Peter A. A. Berle,
Commissioner
April 1, 1977
Mr. J. A. Weiss
Chief, Engineering Division
New York District, Corps of Engineers
26 Federal Plaza
New York, New York 10007
Dear Mr. Weiss:
Draft Environmental Impact Statement
Flood Control Project for
Mamaroneck and Sheldrake Rivers Basin
and for Byram River Basin
DEC Project No. 360-99
We have reviewed the above noted document and do not have any comments
on the statement. Since we are involved as a non-Federal interest in the
proposal, we will review additional information as it becomes available
and specific plans are developed.
Thank you for the opportunity to review this statement. We would
like to receive three copies of the Final EIS when it is available.
Very truly yours,
c-� i�D
erence P. Cu , DC�or
Office of Environmental Analysis
A14
0�e
STATE OF CONNECTICUT
DEPARTMENT OF ENVIRONMENTAL PROTECTIONSTATE OFFicE BUILDING HARTFORD, C.ONNEcncUT 06115
W
ry�rY.r
March 7 , 1977
Colonel Thomas C. Hunter , Jr. , District Engineer
U . S. Army Engineer District , New York
Corps of Engineers
26 Federal Plaza
New York , New York 10007
Dear Colonel Hunter :
RE : Flood Control Project - Byram River Basin : Draft
Environmental Statement
Through ongoing coordination , the Connecticut Department of
Environmental Protection has been involved with the Corps of
Engineers in formulation of a plan to reduce chronic flooding of
the Byram River in the Town of Greenwich . We feel that the
recommended proposal as outlined in the Draft Environmental State-
ment is the most effective alternative among those studied and we
encourage its implementation .
Despite D . E . P . ' s endorsement of the flood control project as
proposed , we feel that in a number of areas inadequate documentation
has been given its environmental impacts in the Draft Environmental
Statement . Where noted , further substantion and additional data
would present a more accurate description of the existing environ-
mental conditions , the project ' s impact and the range of practical
mitigation measures . More specific comments on the Environmental
Statement are attached .
The Corps of Engineers proposes a number of mitigation measures
for the Byram River project which we endorse . We request that DEP
be provided with the final Byram River design plans for review and
comment , to insure that all feasible measures are taken to eliminate
or reduce adverse impacts .
I look forward to further cooperation with the Corps of
Engineers in their successful completion of the Byram River Flood
Control Project .
Yours truly�
Stant eyJ'(. Pac
Commissioner
SJP : iw
A15
a
Connecticut Department of Environmental Protection Comments
on the Byram River Basin Flood Control Project :
Draft Environmental Statement
General Comments
The format of the Draft Statement is confusing , which renders
evaluation difficult . A more legible format would be completely
separate discussions and evaluations of the Byram River Basin and
Mamaroneck and Sheldrake Rivers Basin project .
Much of the quantitative data on chemical , physical , and bi -
ological parameters , on which numerous assumptions and conclusions
are based , is absent from the statement . Lack of such data prevents
D . E . P . from verifying or concurring with statements regarding the
degree of impact the proposed project will have on the Town of
Greenwich .
Line Comments
Section 1 . 17 The benefit-cost ratio of 1 . 7 conflicts with the
figure given in Table 1 .
2 . 25 A claim for sufficient water supply for present
and future needs in Southwestern Connecticut is
neither documented nor referenced .
2 . 29 The water quality classifications for Connecticut
waters , and for the Byram River , were revised in
1976 .
2 . 30 Municipal sewage discharges from the Town of
Port Chester will be eliminated in the near future .
2 . 37 Some species listed in this paragraph are omitted
from Appendix A - the Biological Inventory . If
marsh plants are present , then inland wetland
parameters need be investigated .
2 . 51 Lack of aesthetic features cited here conflicts
with Section 2 . 37 , in which a pleasant aesthetic
character is noted .
3 . 07 No assessment of the chemical character of pro-
posed dredge spoils is provided . Given the
existing water quality in the Byram River , it is
possible that any dredged sediments will be
polluted . Land disposal of such sediments should
be evaluated .
4. 06 Discussion of sedimentation impacts is very general .
No effort is made to tie erosion and sedimentation
potential to specific soil types , mentioned in 2 . 23 .
A16
-2-
4 . 09 Discussion of water quality impacts is somewhat
speculative . Absence of hydrologic data , both
existing and projected , prevents us from evalu-
ating the project ' s impacts on water quality to
our satisfaction .
4 . 20 If construction occurs during spawning periods ,
spawning and breeding will be severely hindered ,
rather than promoted .
The project description includes installation of a ,
sill at the mouth of Pemberwick Lake to maintain
lake level . There is no indication as to the height
of this sill . If the sight is greater than one
foot it could act as a barrier to migrating fish .
4 . 34 Mitigation measures , including installation of a
low flow meander channel and gabbion wire baskets ,
are strongly encouraged . If the Pemberwick Lake
sill is a barrier to fish , we recommend that design
be modified to eliminate that barrier or provide
a means to allow free passage of fish around that
barrier . We request the opportunity to review
design plans to assure that adequate mitigation
measures are undertaken .
6 . 03 A numerical value for the standard project flood
would be appropriate .
7 . 01 Inadequate discussion is given in this paragraph
to biological productivity and aesthetics . With
additional data on stream flow, water quality and
biological parameters , it will be possible to ex-
pand the evaluation of long-term productivity .
8 . 01 Comments on 7 . 01 apply to this paragraph as well .
Appendix A . The biological inventory contains numerous nomen-
clature and spelling errors . The list appears to
include all species which could conceivably be
found in the project area , whether in fact they
exist or not . A more accurate representation of
the flora and fauna would be based on actual
observation . In addition , there is little re-
lationship between the list presented and the
analysis contained in the Environmental Statement .
Reference should be made to " Rare and Endangered
Species of Connecticut and Their Habitats . " Many
of the species listed in the Appendix are rare
and endangered in Connecticut , yet no mention is
made of this status , or the project ' s impact on
rare and endangered species .
A17
/GgE E
zy
INLAND WETLANDS AND 701
WATER COURSES AGENCY
S E A.
TOWN OF GREENWICH
CONNECTICUT
FLOOD CONTROL PROJECT
FOR THE B=,i RIVER BASIN
GREENWICH, CONNECTICUT
February 24, 1977
As the Inland Wetlands and Vater Courses Agency' s Administrator
for the Town of Greenwich, Connecticut, I have reviewer: the Draft
Environmental statement for the proposed Flood Control project
locate; in the Bvram River Basin Greenwich, Connecticut and
Port Chester, N.Y.
The "NED Plan" for flood control on the lower stretch of the
Byram River would involve : a. 2700 feet of charnel dredging,
b. the placement of occasional ria rap, c . the construction of
1360 -feet of floodwall, d. the constriction of 3000 feet of
flood levee, e. the installation of a concrete sill, f. the
construction of a pump station and g . the installation of storm
drainage intercepters and: other interior drainage facilities .
In ?eveloring the cost-benefit ratio, for the NED an_i EQ-Plans
it was unclear how the various figures were arrived at. A more
dete-— brEakiown of the costs and benefits is require- The break-
down should include costs of each major item (walls , levees , pump
station etc . ) anu specific benefits (i .e. savings ner floo:=e '
household or industry) . In a.:dition, a Zi=cussion of the estimated
Lloo � losses for the June Z:7?_ -floo� should be speci=fed.
The fish ana wildlife habitat evaluation, within the study area
is deficient. In addition to being exceedingly brief, the fish,
vec_:-ation, wily-'life and habitat surveys appear to have been
generate, from a literature search rather than actual field survey.
I- field surveys were complete.-I, the number of days spent surveying
the study area as well as the qualifications of those who completed
the survey should be indicated.
_Numerous times i n the statement, fish, wildlife an.- vegetation/
ha:;itat resources were describe:: asmarci nal without anv real
A18
^1lt•o:r Control i'. j act ebru2ry 2-� _977 page 2
documente justification. For such a highly :developer urban area,
sections of the eroject area are in an extremely viable state when
compared to other rivers in the area.
The statement does a good job in evaluating the adverse impacts
associated with NED Plan. in essence, the report revealE?. that the
entire natural, riverine/flood plain habitat within the project area
will be destroyed. In a__ition, it was clear that re(3ular maintenance
of the im^rove~ channel woul.: severely lir;it the rees tab'ishrrrent o=
normal aquatic habitats. In fact, regular crlan_lel maintenance
could have as severe adverse impacts as t'i& actual construction
activities .
Numerous reco=m.mendations ,.:ere ,.a .e to -_itica.te adverse environmental
impacts associate: with the NED Plan. At the minimuT, all these
recommenaations shoul:r be for any Floor: control plan that
is implemented. The mitigation measures included:
a . the maintenEnce or reestabli shnrent of strew:;.
and, floo.:7 plain vegetation.
b. the implementation of adequate se frentation an
erosion control measures .
C. the creation of a low flow charnel with riffles
ana pools and if possible ox bow meanders .
d. the implementation of a significant tree/shrub
replanting Man.
e. the proper sill design to alloy: fish migrations .
yore attention in the rival LIS shoul,� be giver: to the stu. y of
alternatives . A unsubstantiate:: statement iE -,.a-'e that upstream
flood :retention is not a practicable solution to the flooginc problem.
Although there may not be enough rlooJ retention area available in
the 3yram River watersheL7- to solve the entire flooc.ing nroblem, it-
appears that there are significant undevelope�; Floc:d storace areas .
A detailed analysis should be made of detention areas within the
watershed in both New York and Connecticut. Such a stu.:v coup:
reveal that as much as 15 to 200. of 100 year stormwatcr runoff
could be detainer'. thus reducing the 100 year floe: elev=-_ons within
the project area .
All filling within inland wetland, water course and flood plain
areas within the Greenwich Connecticut sections of the 3yram River
watershed are regulate : by local or:.finance. This regulation limits
the amount of development, preserves hoop: storage areas and
significantly reduces future increases in sto-nn runoff rates- within.
the watershed. The EIS should review the lane use patterns of wetlands
in "3.Y. State. Are the filling/ ::estruction of floo
A19
ozv
zcTzzTa-uT�'r= 3_u214ay, �ueTUI
2�IaSn� •� Ia=ua-s
aan5-_ oT aeTT-.uTs SuTpie:r ueTd e rue 'u2Td au-4 *ggTy ,aTeToosse
sT02�1.L'T aszaAre 3zT?:
APPENDIX A
LETTERS RECEIVED BY THE
CORPS OF ENGINEERS AS A
RESULT OF COORDINATION OF THE
DRAFT ENVIRONMENTAL IMPACT STATEMENT
1Z
DEPARTMENT OF AGRICULTURE
• '�sr OF: CE OF THE SECRETARY
WASHINGTON. 0. C. 20250
December 8 1978
Lieutenant General J. W. Morris
Chief of Engineers
Office of the Chief of Engineers
Army Corps of Engineers
U.S. Department of the Army
Washington, D.C. 20314
Dear General Morris:
This is in reply to Colonel Thorwald R. Peterson's letter of August 23,
1978, transmitting for our review the proposed report of the Chief of
Engineers on Mamaroneck and Sheldrake Rivers Basin and Byram River Basin,
Connecticut and New York together with other pertinent reports and a
revised draft environmental impact statement.
The report addresses frequent flooding along the Mamaroneck, Sheldrake,
and Byram Rivers occurring from prolonged heavy rainfall . The flood
problems are caused mainly by inadequate channel capacities, low banks, and
poor channel alignment.
Proposed improvements to protect the village of Mamaroneck consist of
tunnel diversion of the Sheldrake River and channel modification with levees
along the Sheldrake and Mamaroneck Rivers. The proposed plan for the
Byram River consists of about 4,500 feet of channel modification and levees .
At 1976 prices, estimated first cost of the recommended plan is $32,669,000
for the village of Mamaroneck and $4,475,000 for the Byram River plan . At
6 3/8 percent interest, benefit-cost ratios are 1 .2 and 1 .5 respectively.
Although it is recognized that agricultural pursuits in these basins are
minimal , housing and other development activities with their associated land
disturbances can create a potential for erosion and sediment problems .
These can impact the effectiveness of the measures proposed under this
program.
The Westchester (New York) and Fairfield (Connecticut) County Soil and Water
Conservation Districts have the capability to furnish technical assistance
to land users and developers . It may be worthwhile to consider conducting
an accelerated program to furnish technical assistance to these land users .
The statement should address the potential for this impact.
B-1
Lieutenant General J. W. Morris 2
The future growth rate in per capita income was projected at the same
rate as per capita income of the New York Standard Metropolitan Statistical
Area . This rate was taken at 2.56 percent and is the historical growth
rate from 1959 to 1969. The per capita income projections of OBERS from
1980 to 2020 show a lower growth rate which you may consider.
Sincerely,
'BC!
B-2
S;a! Regw .
E „•„a nn 26 c
=.EPA
1 S OCT 1975 Class. LO-2
Mr. J.A. Weiss
Chief, Engineering Division
New York District, Corps of Engineers
26 Federal Plaza
New York, New York 10007
Dear Mr. Weiss:
We have reviewed the revised draft environmental impact statement (EIS)
for the Flood Control Project for the Mamaroneck and Sheldrake Rivers
Basin in the Village and Town of Mamaroneck , Westchester County, New
York and for the Byram River Basin in the Village of Port Chester,
Westchester County, New York and the Town of Greenwich, Fairfield
County, Connecticut.
We have no objection to the proposed project, provided that the
recommendations made by the U.S. Fish and Wildlife Service in the
Fish and Wildlife Coordination Act Report arecomplied with. The
final EIS should discuss this report and how its recommendations will
be implemented .
In accordance with EPA procedures we have rated the revised draft EIS
as category LO-2, indicating that we lack objections over the proposed
project (LO) and that more information is needed before we make a
final determination (2) .
One copy of the final EIS is requested for review.
Sincerely yours,
Michael P. Bonchonsky
Acting Chief
Environmental Impacts Branch
B-3
DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
X60 PUBLIC HEALTH SERVICE
J CENTER FOR DISEASE CONTROL
ATLANTA. GEORGIA 30333
TELEPHONE. (404) 633.3311
October 2 , 1978
Lieutenant General J. W. Morris
Chief of Engineers
Department of the Army
Washington, D. C. 20314
Dear General Morris:
We have reviewed the revised environmental statement for the Flood Control
Project for Mamaroneck and Sheldrake Rivers Basin (Village and Town of
Mamaroneck, New York) and for Byram River Basin (Greenwich, Connecticut
and Port Chester, New York) . We are responding on behalf of the Public
Health Service.
No foreseeable adverse health effects were noted in this statement. How-
ever, it is possible that the drop structure could become a breeding site
for black flies (Simuliidae) , which can be aggravating pests to both humans
and livestock, but are not known to be disease vectors in the United States.
Black flies have been problematic in parts of New York and Dr. Thomas Bast,
Associate Medical Entomologist, State Department of Health, 84 Holland Avenue,
Albany, New York 12237, should be consulted for his opinion in this matter.
Thank you for the opportunity of reviewing this document. We would appre-
ciate receiving a copy of the final statement when it is issued.
Sincerely yours,
Frank S. Lisella, Ph.D.
Chief, Environmental Affairs Group
Environmental Health Services Division
Bureau of State Services
B-4
'`roar of
DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
V
HARTFORD AREA OFFICE
ONE FINANCIAL PLAZA
o,3NNNN^�M.a� HARTFORD, CONNECTICUT 06103
REGION I
Room 800 nctober 6, 1 Q7O
John F. Kennedy Federal Budding
Boston, Massachusetts 0:203 '1 REPLY REFER TO:
Lieutenant General J . W. Morris
Chief of Engineers
Department of Army
Washington, D.C. 20314
Dear General Morris :
C+atcmnn+
Byram RiverBasin
Greenwich, Connecticut
This is in response to your August 23 , 1978 letter requesting our comments
on the above project.
Our review of the Impact Statement was confined to the effect the flood control
project would have on any existing or proposed programs this agency is or
contemplates assisting. Since there does not appear to be any such
assistance at this time we have no comments to offer.
We appreciate the opportunity to review such projects within the Hartford
Area Office' s jurisdiction.
Sincerely,
Lawrence L. Thompson
Area Manager
B-5
Pay F
United States Department of the Ii re; �.�
OFFICE OF THE SECRETARYWASHINGTON, D.C. 20240
PEP ER 78/839
Lieutenant General J . W . Morris
Chief of Engineers
Department of the Army
Washington, D . C . 20314
Dear General Morris :
This is in reply to a letter from your office dated
August 23 , 1978 , requesting our views and comments on
your proposed report and revised draft environmental
statement for the Mamaroneck and Sheldrake Rivers Basin
and Byram River Basin flood control proposal , Connecticut
and New York.
While we do not object to the proposed report of the Chief
of Engineers on this project , we find it difficult to
support the project from a fish and wildlife standpoint .
By letter of September 13 , 1977 , our U . S . Fish and Wildlife
Service provided your District Office with its findings on
their proposal and it contained several recommendations for
avoiding or reducing the project caused impacts on the fish
and wildlife resource base . Since the correspondence was
not in the District Engineers ' report , we have no insight
as to his views on the recommendations or the reasons why
they were not adopted . Accordingly , we wish to condition
our support of your proposal to the following :
1 . The report of the Chief of Engineers be revised to
recommend additional detailed studies of the fish and
wildlife resources in the study area in accordance with
Section 2 of the Fish and Wildlife Coordination Act (48
Stat . 401 as amended ; 16 U . S . C . 661 et . seq . )
2 . Your report seek the authority to permit such reasonable
modification to the project and/or its operation as may
be agreed upon by the Director , U . S . Fish and Wildlife
Service and the Chief of Engineers for the conservation ,
improvement and development of the fish and wildlife
resources in the study area .
B-6
2
We have completed our review of the revised draft environ-
mental statement for this proposal . The statement contains
an adequate discussion of the project ' s impacts on our
areas of jurisdiction and/or special expertise . However ,
we do believe that the statement would be improved by the
adoption of the recommendations to reduce the adverse impacts
on the fish and wildlife resource base .
We wish to thank you for the opportunity to comment on your
proposed report and supporting documents .
Sincerely,
SECRETARY
B-7
New York State Department of Environmental Conservation AM
50 Wolf Road, Arany, New York 12233 taboo
Peter A. A. Berle,
Commissioner
October 23 , 1978
Lieutenant General J . W. Morris
Chief of Engineers
Department of the Army
Washington, D. C . 20314
RE: Revised Draft Environmental
Impact Statement , Flood
Control Project for Mamaroneck
$ Sheldrake Rivers Basin and
for Byram River Basin, Port
Chester, NY .
DEC #360- 14-
Dear General :Morris :
The Department of Environmental Conservation has completed its
review of the above noted document and has no comments to offer
at this time .
Thank you for the opportunity for review. We request review of
the final document when available .
Very `truly yours ,
Terence P . Curran, Director
Office of Environmental Analysis
TPC : ER.M/scs
cc : G . Danskin
File 360-14
B-8
I r I :;I
N EC T I C U T
kD t C 0 ti
IN
D E('A RTNA LN'T, OF E N','!
IENTAL PI"C)TECTION
STATr Ori icy )W11 DING 11AWIFORD, (k)NNYMICUr 06115
December 19 , 1970
,"Ir . F . R . Pagano
Chief , Encineering Division
ne p i r - of the Army
i i C Y 0-1; 11)i strict , Corps of Engineers
26 Federal Plaza
N e w Y o r1r. , N . Y . 10007
.pear Mr . Pagano,
This department has reviewed the DEIS on the Mamaroneck ,
Sheldrake and Byram River Basins flood control project .
L.
The one concern of this department is to see that
environ-,,,cntal considerations for fish restoration are
incorporated into the final design of channel modification
for the Byram River through Greenwich , Connecticut .
Sincerely ,
S L a ii I e� Pd C
Commissioner
S J P ED : i
B-9
APPENDIX C
BIOLOGICAL INVENTORY OF
MAMARONECK, SHELDRAKE AND
BYRAM RIVER BASINS
Biological Inventory
Freshwater Fish
Scientific Name Common Name
Lepomis macrochirus Bluegill sunfish
Lepomis auritus Redbreast sunfish
Lepomis gibbosus Pumpkinseed sunfish
Micropterus salmoides Large mouth bass
Carassius auratus Goldfish
Cyprinus carpio Carp
Esox niger Chain pickerel
Notropic cornutus Common sucker
Notemigonous crysoleucas Golden shiner
Notropis spp. Shiners
Pimephales spp. Minnows
Common Estuarine Species
Osmerus mordas Rainbow smelt
Anquilla rostrata American eel
Morone americana White perch
Pseudopleuronectes americanus Winter flounder
Paralichthys dentafus Summer flounder
Myoxocephalus aenaeus Grubby
Hemitripterus americanus Sea raven
Alosa pseudoharengus Alewife
Alosa sopidissima American shad
Brevoortia tyrannus Atlantic menhaden
Merluccius bilinearis Silver hake
Microgadus tomcod Atlantic tomcod
Cyprinodon variegatus Sheepshead minnow
Fundulus heteroclitus Banded killifish
Mendia beryllina Tidewater silverside
Menidia menidia Atlantic silverside
Morone saxatilis Striped bass
Pomatomus saltatrix Bluefish
AMPHIBIANS*
Scientific Name Common Name
Bufo americanus American toad
Rana sylvatica Wood frog
Rana clamitans Green frog
Hyla crucifer Spring peeper
Diemictylus viridescens Red eft
Ambystoma opacum Marbled salamander
Desmognathus fuscus Northern dusty salamander
Rana pipiens **Leopard frog
Bufo woodhousei **Fowler ' s toad
Plethodon cinereus "Red-backed salamander
Ambystoma maculatum **Spotted salamander
Plethodon glutinosus **Slimy salamander
* Stream alteration would probably eliminate all amphibians except
the American Toad from the vicinity of the project area.
** These amphibians may also be present in the project area.
C-1
REPTILES
Scientific Name Common Name
Terrapene carolina *Eastern box turtle
Chelydra serpentina *Common snapping turtle
Chrysemys picta *Eastern painted turtle
Elaphe obsoleta Black rat snake
Coluber constrictor Northern black racer
Lampropeltis doliata Milk snake
Thamnophis sirtalis Eastern garter snake
Thamnophis sauritus Eastern ribbon snake
Storeria dekayi Dakays snake
Diadophis punctatus Northern ring-necked snake
Opheodrys vernalis Smooth green snake
Natrix sipedon *Northern water snake
Carophophis amoenus Eastern worm snake
* Indicates which of those species, listed, are expected to be
affected by channel modification and clearing of vegetation adja-
cent to the stream. These populations are expected to be de-
creased or eliminated in the project area.
BIRDS
Scientific Name Common Name Comments
Larus argentatus Herring gull Resident
Branta canadensis Canada goose *Migrant
Anas platyrhynchos Mallard *Probably Breeds
Anas rubripes Black duck Occasional Visitor
Aix sponsa Wood duck Occasional Visitor
Colinus virginianus Bobwhite Resident
Falco sparverius American kestrel Resident
Charadrius vociferus Killdeer Occasional Migrant
Actitus macularia Spotted sandpiper *Rare migrant
Columba livia Rock dove Resident
Zenaidura macroura Mourning dove Resident
Otus asio Screech owl **Resident
Bubo virginianus Great horned owl **Probable resident
Strix varia Barred owl **Probable resident
Caprimulgus vociferus Whip-poor-will Migrant, may breed
Chaetura pelagica Chimney swift Migrant, may breed
Archilocus colubris Ruby-throated
hummingbird **Migrant, may breed
Megaceryle alcyon Belted kingfisher *Migrant
Centurus carolinus Red-bellied woodpecker **May be resident
Dendrocopos villosus Hairy woodpecker **Resident
Dendrocopos pubescens Downy woodpecker **Resident
Tyrannus tyrannus Eastern kingbird Migrant, breeds
Iridoprocne bicolor Tree swallow Migrant
Riparia riparia Bank swallow Migrant
Progne subis Purple martin Migrant
Cyanocitta cristata Blue jay Resident
Corvus brachyrhychos American crow Resident
Empidonax alorum Willow flycatcher Migrant
C-2
Scientific Name Common Name Comments
Parus bicolor Tufted titmouse Resident
Sitta carolinensis White-breasted
nuthatch **Resident
Certhia familiaris Brown creeper **Migrant
Troglodytes aedon House wren Migrant, breeds
Troglodytes troglodytes Winter wren **Rare migrant
Mimus polyglottos Mockingbird Resident
Turdus migratorius Robin Resident
Hylocichla mustelina Wood thrush **Migrant, breeds
Hylocichla minima Grey-cheeked thrush **Migrant
Regulus satrapa Golden-crowned kinglet **Migrant
Regulus calendula Ruby-crowned kinglet **Migrant
Sialia sialis Eastern bluebird Rare Migrant
Buteo jamaicensis Red-Tailed hawk Resident
Arcus cyaneus Marsh hawk Resident
Pandion haliaeetus Am. osprey Rare Migrant
Falco peregrinus Peregrine falcon Rare Migrant
Bombycilla cedrorum Cedar waxwing **Resident
Sturnus vulgaris Common starling Resident
Vireo griscus White-eyed vireo *Migrant, may breed
Mniotilta varia Black and white
warbler **Migrant, breeds
Dendroica petechia Yellow warbler *Migrant, breeds
Dendroica virens Black-throated green
warbler **Migrant
Dendroica pinus Pine warbler **Migrant
Seiurus aurocapillus Ovenbird **Migrant, breeds
Seiurus noveboracensis Norther water-thrush Migrant
Oporornis agilis Connecticut warbler Rare migrant
Wilsonia canadensis Canada warbler **Migrant
Setophaga ruticilla American redstart **Migrant, breeds
Passer domesticus House sparrow Resident
Agelaius phoeniceus Red-winged blackbird Resident
Icterus galbula Northern oriole Migrant, breeds
Euphagus carolinus Rusty blackbird *Migrant
Quiscalus quiscula Common grackle Resident
Molothrus ater Brown-headed cowbird Resident
Piranga olivacea Scarlet tanager **Migrant, breeds
Richmondena cardinalis Cardinal Resident
Carpodacus purpureus Purple finch **Migrant
Carpodacus mexicanus House finch Resident
Acanthis flammea Common redpoll Rare Migrant
Spinus tristis American goldfinch Resident
Junco hyemalis Dark-eyed junco Migrant
Spizella arborea Tree sparrow Migrant
Spizella pusilla Field sparrow Migrant, breeds
Melospiza lincolni Lincoln' s sparrow **Migrant
Melospiza melodia Song sparrow Resident
* Indicates which of those species, listed, are expected to be
affected by channel modification and clearing of vegetation ad-
jacent to the stream. Those species indicated which are
breeders will probably no longer breed in the project area . All
other species indicated will be eliminated as a migrant to the
project area.
** Species which are heavily dependent on a woodland habitat and
which are not expected to exist in the altered project area, are
so indicated.
C-3
VEGETATION
Scientific Name Common Name
Ulmus americana American Elm
Liquidambar stypaciflua Sweetgum
Populus tremuloides Quaking aspen
Fraginus americanna White ash
Fraginus pennsylvania Green ash
Acer rubrum Red maple '
Acer saccharum Sugar maple
Liriodendron tulipifera Tulip tree
Nyssa sylvatica Black gum
Quercus alba White oak
Quercus rubra Red oak
Betula lenta Black birch
Betula papyrifera White birch
Salix babylonica Weeping willow
Salix nigra Black willow
Sally discolor Large pussy willow
Fazus grandifolia American beech
Robinia pseudoacacia Black locust
Platanus occidentalis Am. sycamore
Alnus glutinosa European alder
Prunus serotina Black cherry
Populus deltoides Eastern cottonwood
Populus alba White poplar
Pinus nigra Austrian pine
Pinus sylvestris Scotch pine
Abies balsamea Balsam fir
Picea eycelsa Norway spruce
Picea mariana Black spruce
Lyonia ligustrina Maleberry
Clethra alnifolia Sweet pepperbush
Rhus spp. Sumacs
Rhus typhina Staghorn sumac
Rhus glabra Smooth sumac
Arctostaphylos uva-ursi Common bearberry
Viburnums spp. Low bushes
Lonicora maackii Honeysuckle
Rubus . allegheniensis Wild blackberry
Vitis spp. Grape
Hedera spp. Ivy
Toxicodendron radicans Poison Ivy
Lythium salicaria Purple loosestriA
Salidago rugosa Goldenrod
Ambrosia artemisii`Folia Ragweed
Rosa multiflora Wild rose
Gramineae Grasses
C-4
MA AMALS
Scientific Name Common Name
Ondatra zibethicus Muskrat
Didelphis marsupialis Opossum
Sorex cinereus *Masked shrew
Sorex fumeus *Smoky shrew
Cryptotis parva Least shrew
Blarina brevicauda Short-tailed shrew
Scalopus aquaticus Eastern mole
Parascalops breweri Hairy-tailed mole
Myotis lucifugus Little brown bat
Pipistrellus subflavus *Eastern pupistrel
Eptesicus fuscus Big brown bat
Lasiurus borealis Red bat
Lasiurus cinereus Hoary bat
Procyon lotor Raccoon
Mustela erminea Short-tailed weasel
Mustela frenata Long-tailed weasel
Mustela vison *Mink
Mephitis mephitis Striped skunk
Vulpes fulva Red fox
Vrocyon cinereoargenteus Grey fox
Marmota monax Woodchuck
Tamias striatus Eastern chipmunk
Sciurus carolinensis Gray squirrel
Peromyscus maniculatus Deer mouse
Microtus pennsylvanicus Meadow vole
Pitymys pinetorum Pine vole
Rattus norvegicus Brown (norway) rat
Rattus rattus Black rat
Mus musculus House mouse
Sylvilagus floridanus Eastern cottontail
* Indicates which of those species, listed, are expected to be
affected by channel modification and clearing of vegetation adja-
cent to the stream. These populations are expected to be de-
creased or eliminated in the project area.
C- 5
APPENDIX D
STATE WATER QUALITY
CLASSIFICATIONS
NEW YORK STATE WATER QUALITY STANDARDS
CLASS C*
Items ** Specifications
1. Coliform The monthly geometric mean
total coliform value for one
hundred ml of sample shall
not exceed ten thousand and
the monthly geometric mean
fecal coliform value for one
hundred ml of sample shall
not exceed two thousand from
a minimum of five examinations.
This standard shall be met
during all periods when dis-
infection is practiced.
2. pg Shall be between 6 . 5 and 8. 5 .
3. Total Dissolved Solids None at concentrations which
will be detrimental to the
growth and propagation of
aquatic life. Waters having
present levels less than 500
milligrams per liter shall
be kept below this limit.
4. Dissolved Oxygen For cold waters suitable for
trout spawning, the DO con-
centration shall not be less
than 7 . 0 mg/l from other
than natural conditions .
For trout waters , the mini-
mum daily average shall not
be less than 6 . 0 mg/1. At
no time shall the DO con-
centration be less than 5 . 0
mg/1. For non-trout waters ,
the minimum daily average
shall not be less than 5. 0
mg/1. At no time shall the
DO concentration be less
than 4. 0 mg/1.
* Source: N.Y. State Dept. of Environmental Conservation, Classifi-
cations and Standards Governing the Quality and Purity of Waters of
New York State, Effective March 27, 1974 .
** Refer to Note 1 under Class D standards.
D-1
NEW YORK STATE CLASS "D"
Best usage of waters. These waters are suitable for secondary con-
tact recreation, but due to such natural conditions as intermittency
of flow, water conditions not conducive to propagabyon of game fish-
ery or stream bed conditions , the waters will not support the propa-
gation of fish.
Conditions related to best usage of waters . The waters must be suit-
able for fish survival.
Items** Specifications
1. pH Shall be between 6 . 0 and 9. 5
2. Dissolved Oxygen Shall not be less than 3 milli-
grams per liter at any time.
** Note 1:
With reference to certain toxic substances affecting fish-
life, the establishment of any single numerical standard
for waters of New York State would be too restrictive.
There are many waters, which because of poor buffering
capacity and composition will require special study to
determine safe concentrations of toxic substances . How-
ever, most of the non-trout waters near industrial areas
in this state will have an alkalinity of 80 milligrams
per liter or above. Without considering increased or
decreased toxicity from possible combinations , the follow-
ing may be considered as safe stream concentrations for
certain substances to comply with the above standard for
this type of water. Waters of lower alkalinity must be
specifically considered since the toxic effect of most
pollutants will be greatly increased:
Ammonia or Ammonium Compounds Not greater than 2. 0 milli-
grams per liter expressed as
NH3 at pH of 8. 0 above.
Cyanide Not greater than 0 . 1 milli-
grams per liter expressed as
CN.
Ferro-or Ferricyanide Not greater than 0 . 4 milli-
grams per liter expressed as
Fe (CN) 6.
Copper Not greater than 0 . 2 milli-
grams per liter expressed as
Cu.
Zinc Not greater than 0 . 3 milli-
grams per liter expressed as
Zn.
Cadmium Not greater than 0 . 3 milli-
grams per liter expressed as
Cd.
D -2
NEW YORK STATE CLASS SB
Best usage of waters. The waters shall be suitable for primary and
secondary contact recreation and any other use except for the taking
of shellfish for market purposes.
Quality Standards for Class "SB" Waters
Items Specifications
1. Coliform The monthly median coliform
value for one hundred ml of
sample shall not exceed two
thousand four hundred from a
minimum of five examinations
and provided that not more
than twenty percent of the
samples shall exceed a coli-
form value of five thousand
for one hundred ml of sample
and the monthly geometric
mean fecal coliform value for
one hundred ml of sample
shall not exceed two hund-
red (200) from a minimum of
five examinations . This
standard shall be met during
all periods when disinfec-
tion is practiced.
2. Dissolved Oxygen Shall not be less than 5 . 0
mg/l at any time .
3 . Toxic Wastes and deleterious None in amounts that will
substances. interfere with use for pri-
mary contact recreation or
that will be injurious to
edible fish or shellfish or
the culture or propagation
thereof, or which in any
manner shall adversely
affect the flavor, color,
odor or sanitary condition
thereof, or impair the
waters for any other best
usage as determined for the
specific waters which are
assigned to this class .
D-3
CONNECTICUT STANDARDS
INLAND WATERS
CLASS B
Suitable for bathing, other recreational purposes,
agricultural uses , certain industrial processes and
cooling; excellent fish and wildlife habitat; good
aesthetic value. ,
1. Dissolved oxygen 75% saturation, 16 hours/day;
5 mg/l at any time.
2. Sludge deposits - solid refuse - None except for small amounts
floating solids , oil and grease - that may result from the dis-
scum charge from a waste treatment
facility providing appro-
priate treatment.
3. Silt or sand deposits None other than of natural
origin except as may result
from normal agricultural,
road maintenance, or con-
struction activity provided
all reasonable controls are
used.
4 . Color and turbidity Turbidity shall not exceed
25 JTU, Bc* 10 JTU.
A secchi disc shall be
visible at a minimum depth
of 1 meter, bb-criteria may
be exceeded.
5. Coliform bacteria per 100 ml Not to exceed a median of
1000 nor more than 2400 in
more than 20% of samples
collected.
6. Taste and odor None in such concentrations
that would impair any usages
specifically assigned to
this class nor cause taste
and odor in edible fish.
7. pH 6. 5 - 8. 0
D-4
8. Allowable temperature increase None except where the in-
crease will not exceed the
recommended limit on the
most sensitive receiving
water use and in no case ex-
ceed 85°F, or in any case
raise the normal tempera-
ture of the receiving water
more than 4°F. Bs - same as
• A.
9. Chemical constituents See Table 1.
* The use of subscript c is to identify areas suitable for cold
water fisheries especially fish passage.
** The use of subscript b is to identify areas suitable for cold water
fisheries including fish spawning and growth.
D-5
CONNECTICUT STANDARDS*
CLASS SB
Suitable for bathing, other recreational pur-
poses, industrial cooling and shellfish har-
vesting for human consumption after depuration;
excellent fish and wildlife habitat, good
aesthetic value.
1. Dissolved oxygen Not less than 5. 0 mg/l at
any time
2. Sludge deposits - solid refuse - None except for small amounts
floating solids , oils and grease - that may result from the dis-
scum charge from a waste treatment
facility providing appro-
priate treatment.
3. Sand or silt deposits None other than of natural
origin except as may result
from normal agricultural,
road maintenance, or con-
struction activity provided
all reasonanle controls are
used.
4. Color and turbidity A secchi disc shall be visi-
ble at a minimum of 1 meter,
SBb - criteria may be ex-
ceeded.
5. Coliform bacteria per 100 ml Not to exceed a median value
of 700 and not more than 2300
in more than 10% of the
samples .
6 . Taste and odor None in such concentrations
that would impair any usages
specifically assigned to
this class and none that
would cause taste and odor
in edible fish or shellfish.
7. pH 6 . 8 - 8 . 5 .
8 . Allowable temperature increase None except where the in-
crease will not exceed the
recommended limit on the
most sensitive receiving
water use and in no case ex-
ceed 83°F or in any case
raise the normal tempera-
ture of the receiving water
D-6
more than 4°F . During the
period including July,
August, September, the nor-
mal temperature of the re-
ceiving water shall not be
raised more than 1. 5°F un-
less it can be shown that
spawning and growth of indi-
geous organisms will not be
significantly affected.
9 . Chemical constituents None in concentrations or
combinations which would be
harmful to human, animal or
aquatic life or which would
make the waters unsafe or un-
suitable for fish or shell-
fish or their propagation,
impair the palatability of
same, or impair the waters
for any other uses.
* Source: Connecticut Dept. of Environmental Protection, Proposed
Water Quality Standards, Approved November 30 , 1976; Effective
December 1977.
D-7
CLASS SC
Suitable for fish, shellfish and wildlife habitat; suitable for
recreational boating and industrial cooling, good aesthetic value.
Items Specifications
1. Dissolved oxygen Not less than 5 mg/l for more
than 6 hours during any 24-
hour period and at no time .
less than 4 mg/l. For cold
water fishery, SCc, not less
than 5 mg/l at any time. SCs
- 6 mg/1.
2. Sludge deposits - solid refuse - None except for small amounts
floating solids, oils and that may result from the dis-
grease - scum charge from a waste treatment
facility providing appropriate
treatment.
3 . Sand and silt deposits None other than of natural ori-
gin except as may result from
normal agricultural, road main-
tenance, construction activity,
or dredge material disposal
provided all reasonable con-
trols are used.
4 . Color and turbidity None in such concentrations
that would impair any usages
specifically assigned to this
class .
5 . Coliform bacteria per 100 ml Not to exceed an average in
any 30-day period of 5000 nor
exceed this value in more than
20% of the samples collected
during the period.
6 . Taste and color None in such concentrations
that would impair any usages
specifically assigned to this
class and noe that would cause
taste and odor in edible fish
or shellfish.
7. pH 6. 5 - 8. 5
D-8
8 . Allowable temperature increase None except where the increase
will not exceed the recommended
limit on the most sensitive
receiving water use and in no
case exceed 83°F or in any case
raise the normal temperature of
the receiving water more than
4°F . During the period including
July, August and September,
the normal temperature of the
a receiving water shall not be
raised more than 1 .5°F unless
it can be shown that spawning
and growth of indigenous org-
anisms will not be significant-
ly affected.
D-9
APPENDIX E
LETTERS OF COORDINATION
CULTURAL RESOURCES SURVEY
United States Department of the Interior
01NATIONAL PARK SERVICE
^ � Office of Archeology and Historic Preservation
IN REPLY REFER To: Interagency Archeological Services -Atlanta
730 Peachtree Street, Room 1010
Atlanta, Georgia 30308
FEB 2 2 1977
Mr. J. A. Weiss
New York District, Corps of Engineers
26 Federal Plaza
New York, New York 10007
Dear Mr. Weiss:
We have received and reviewed a copy of a report entitled Reconnai-64ance
Levet Survey of Cuitivwt Raounca Mamaroneck Riven Bazin and Bynam RiveA
Bazin Hood Con too Pno1ect,6 by Karen D. Zukerman and Nan A. Rothschild
and find it an acceptable reconnaissance level investigation. Enclosed
is a copy of our reviewer's comments for your information.
Sincerely yours,
Victor A. Carbone
Acting Chief, Interagency
Archeological Services-Atlanta
Enclosure
�P�GAN qF` E-1
O
rn2
l�,s �dlNN31�n0
-�� United States Department of the Interior
NATIONAL PARS SERVICE
�^d Of ice of Archeoi-)gy and Historic Presen-ation
IN REPLY REFER TO: Interagency Archeological Sen-ices - Atlanta _
730 Peachtree Street, Room 1010
H2219-SER-PIA Atlanta, Georgia 30308
s
Memorandum
To: Chief, Interagency Archeological Services-Atlanta
From: Intern Archeologist, Interagency Archeological Services-Atlanta
Subject: Comments on A ReccnnaZ6zance Levu Survey o6
Mamah.oneck and She c-1-tate R.i.vvL SaSin and dytan Xive,% Sasui r.C-c-ed
Conttot P.-uojeeta by Karen D. Zuke-man and Nan A. Rothschild
The documentary research seems to have been thorough and well done.
The field survey also seems to have been quite thorough, although the
archeologists seem to have taken only habitation sites into considera-
tion and to have dismissed any areas where habitation was not feasible
as therefore not possibly having any cultural resources. The sources of
borrow for levees and the places where dredgir.gs will be put were not
specifically considered.
In her suir=ary, Ms. Rothschild said that "essentially no `rational
Register-eligible cultural resources" would be affected by the project.
The inclusion of the word "essentially" does not make sense, unless it
is just a hedge. The National Register related recommendations leave
some room for question. The fact that the Delancey House (Fenimore
Cooper Inn) has been moved as well as partially reconstructed probably
affects its eligibility. The Homelite factory, which was built in 1900,
perhaps should have been considered as potentially eligible for the
National Register. Additional consideration of the effect of the project
on it might also be merited.
There were several typographical errors. Presu^ably Johr. Peter deLancey
did not actually occupy the house he built from 1792 until his death
in 1928.
Intern Archeologist
.:�,?�\CAN qFL�
' E-2
2
S`S
D RE'r
NEW YORK STATE PARKS&RECREATION
3176
April 12 , 1977
Mr. J.A. Weiss
Chief, Engineering Division
New York District, Corps of Engineers
26 Federal Plaza
New York, N.Y. 10007
Re : Reconnaissance Level Survey of
Cultural Resources Mamaroneck River
Basin and Byram River Basin Flood
Control Projects
Dear Mr. Weiss :
This letter will serve to provide the comments of
the State Historic Preservation Officer on the survey report
for the above referenced project. The State Historic Preser-
vation Officer is in agreement with the conclusions of the
report that the project will have no effect on cultural
resources listed on, or eligible for the National Register of
Historic Places. We understand from your letter of January 31 ,
1977 , that the Corps will implement recommendations presented
by the consultant for protecting the Mamaroneck Waterworks
building, the DeLancy House and structures along the east side
of the Mamaroneck River between station 80+00 and 90+00 ,
should any of these structures at any time appear to be
effected by the project.
Please consult the project review staff at 518-474-3176
should you desire to discuss this comment.
Sincerely,
F.L. Rath, Jr.
Deputy Commissioner for
Historic Preservation
E-3
O$icc o1 the
STATE
HISTORIC
PRESERVATION
OFFICER
for Connccticut
Tl/ 11.1 R'7'b'( RI). C��\\f:C7"]C(T Io,i iii ���:; 56ti-; d,
April 14,1977 `
Department of the Army
New York District, Corps of Engineers
26 Federal Plaza
New York, N.Y.10007
Attn: Mr. J. A. Weiss
Chief, Engineering Division
Subject: Reconnaissance Level Survey of Cultural Resources
Mamoroneck River Basin and Bvram River Basin Flood
Control Projects
Dear Mr. Weiss:
The State Historic Preservation Officer has reviewed the above named
Archaeological Reconnaissance Survey Project Report conducted and
prepared by Ms. Karen D. Zukerman and Ms. Nan A. Rothschild, of the
Archaeological Resource Management Service, of the New York Archaeological
Council.
The State Historic Preservation Officer has examined this project report
with respect to: 1) the appropriateness and professional quality of the
field methodologies employed, and 2) the significance of the results
and data unearthed.
In accordance with the responsibilities under the National Historic Preser-
vation Act of 1966 (80 Stat 915, 16 USC 470 as amended) , and Advisory
Council Procedures 36 CFR Part 800, the State Historic Preservation Officer
expects that this project will have no impact on Connecticut's archaeological
resources.
erely yours, oe '
DP:aasohn W. �n a an
State lKstoric Preservation
Officer
E-4
APPENDIX F
U.S. FISH & WILDLIFE SERVICE
REPORTS AND CORPS OF ENGINEERS
LETTERS OF REPLY
V
L) S
:i;
Q j7 C7
A"�j
Y 12-045
13 , 1978
16
ColonE,1 Clark H. Ccnn
`,-w Y^r'h Disti-ict, CorDs cf E no; n
FLj;2r5' Plaza
York 1 0007
Dear Colon;:? E2rin-
ThisI.. , i LLo,,,-
j, report r, the e;fects the cortrol
s for flamaronec lk nd Sl--I d-,ike R 4,vcr s 4i ns , Vi I I a t-ic z.;�d T-,,.:tn
G. MJi' ompck, 'A'72stches ter County, Ycrk,, Wi 'I ha vc cn f-i s h a.-i'd
r(-io::r:cs. it was prep,red u'er the au,.h,r ;-Lv vi a!id -'i-a n L-Eaccud-
n.�, o the F s I i d i 10.-1 ':f e C,)-,rd'i n�,t-i o n Act ("S Stat.
, i- 'h �rcvis,
63 U. S.C. 6The project iqas ail z!,u
!1 j
for ty r-5c-)'V-4CnS OF I'. SE-.-j�t-
United S t:-t p s C r..—
Tee c
o r r dp t I e d 4 S e rn t e m.b e i- '3 ?lid m er
1:s
P,, b r
,do-
, p,"e Jurc r�tpcl,,t 1hes I-1 c c r c,o I-d i n d �al th D s i t-ii
of Fi.-A, in-' '.Nflift 0 h q lNew Yerk. Stale Dunarl*mran'- of Env i
4; 'intv.-ndLd to !''7!ic zi I r.n cot
Ccr:c--- rN r'10 Orad i
co o n tm3 ,, 1, inp r,:i n0 v n a
of -.4 z ie, c i7,!-, e rs
I L /jti
r'*:r! L.-I ov zf )C1
r Do a
Prcilli!ct Dcscr-ipl.ion
V i c C. c a r,.1 r,-,c R ver, Ma r u i i e c New Y c k
Th k� s c j plan f o- to m a--c i?c k R1 Vi i I z,r 7 c f i Uam a.-o me,c 1; N'c w Y o r
ri ng Y:c,
Son c f C.h a;,n t� f., v r c I.,
• - i.
bridne replaccm—ants. The cxist*,n,+ ch nnc•': of the River would
be widcrcd ani e_ red from a p, ir:t dc:: tr^a.: of Tc: )Hn; Pven-;e upstream
to Itiinficld Ami..:c , a distance of io,000 feet. The modified
channel bottom along the P i ver ► _ .:l vary in ti•:i-'.h fro:',. 60 feet
at the 1;;: er lit^it o the plan to 45 feet in :tip th at t`.e tr _trc:a limit
of Vie "':an. The ch�.nr.;l moJificaticr, +:'aulc include the relocation of the
Ct.r�! i' c' .i.t' Qf tr� r n rr_ C�,n,Ir I`i.. + l to • n :o
c�: �, c . :rs �G e it i na �h tti.
'.tarp L�.CS in
the e\i_'. ,na dll�r.- _^i., c" Cor:stru:tliln Of a riL'r:-r Ci
ir_-us retairii.a %•;all; ; In d�� tic^ , th_ plar call; fc;r the rcplace-
!�: it Qf ti;:. . -rd , hasi tea.d, Station Plazal llSid:_' AVC-7 -'.". E;ridr.c5 ,
p1 us r_•pl --,z--n t of `hn Va 11 ey f 1 ace Se:.'cr bridge .'i th an inverted s rhon.
w, 17. be Prc .'id:-_ by a SSS'.:^ of ditch; and c;:tlet drain.'.
thr0i: .h the llrc of Ct�CtiG'. ar:;• Scveral ?s along the strea7�.s will be
filled ard "Die an`,iCirz:i:u Frzjezt 'ii 'e is 100 fears .
t,rill3^
of River, "d"drC '�Ci;, �;'c'.�' YO-k
The seie:ted plan calls for the diversion of t`te Sheldrake River into a
tunnel c _ Feni'r.Qre RQ2u leadinti to t`:? :..est _u in of i
3.
Aq-atic and Terrestri.. resourcos
r General
o The iiamaroneck River Basin ir.clud-ing its tri L,tarV, ilio 'ShelRiver,
OCCU^ies a L1.4 quar _ Ca le arca of scU',hf .-„ ,ern ';cstc."•C.'s er Co'u!-t;,
r'- or 1;h.it
- t,e:�r Y�.. k. In,. ,,._ � .i ` in i ' s bour, ,,
., ric_ ,.• �-: �, . ,.n2 Cities c,
P a i n, ar,' r i, � l r`c F r r f ,. n`, ' rth
• c � e, pa c, t,.e T: c. }i^rrison , .uta�ro cr: , � �,{
E Castle, arc' Scarsdale an-- Dart Of the "i1I of This waters}'ed ,
drainir, 7 {i:r0 Lcri:, ,, tan,. Sour, iS the f 0 a ' i:. • „-'ICd
eIcnQat_� , ci .i^ e. Its 9.2 il'_s , e) ,C ds to a genera .
nor ^-sc :�t• dirnc�- _ lt; L. _ 'a; y cc-..> Ist, c` con,,1�" rolling to, t... ldly
ru�Ced hills , the iG'•._ slopes of vhich icrm a dert�ritiC Of
cc ,parat i : '13, narrc. `alleys . Cro;:nd elevations, rare frca r:car mean sea
level at the t:,Duth o- r o^e;k Pivcr to about :,CC feet ab,-:e mean
sea IUVE1 in the no ;.h_ :st cf the . asin.
The P'a...arc^_•ck River rises dc-,-.1r.strea,r of Leke , in the north•_rn section
of arr;ccn N ,+-I” a �r r'' ' ort• 1 � �1, i, ,nce
. h�. ,r�••, .tCW 1',,. .. The rl��, t tcr:, c,.,{.ra , ly ..o;._ , for a c .., �„,.,.,. o.
• at`c,.t . i r: les to Long Island round , which it enter_ t;nrough `'.-.aroneck
r
Harbcr.
The Sheldrake River rises in the northeast portion of Scarsdale, 'New
York., The river flovis 9,urerai lv south-southe-.st fcr a distance of. about
*� 7.� mi lcs an^ Joins the River at a � „ tr`� about 0.6 riles
r abG:'_ i .s r Jtn• Ore major kno,,'.', asthe East Cr?,.nch of the
Sh.-1:.. . .e ,,aver, en:ers the `�i': t�raf':e Rid' r at a ;join'. l .8 i l Ie5
tiie ccnf l ut:m,:e of the She ldr.,ka and htarr.arene:k Ri vers .
Y
-T b''iSu31 1r:;reCt10R: Of the river` indicate thc,t tl: rti .s are ciE'.., and
Nr�Seit n" aesthuticalij a,r2a!'anc'e in v.,, is a hti urbar,iZed
ar?a . Tne rivers are sna110., _,!rine. tib Of r;,nqing
from at,cut 1 to 5 -;e,7 _. Th: - Rivir bottom is co—c—;e . o' rock.,
bo. ...erS , rUd, ant: $i I t ar. reG$ the vttC;;i of"i h_ UL'-, ..
Lr , _lc. r Cort-
sists cf sclid rock, beu%ers , stere, anc' travel . The uprer ShelcraG.3
River s of exceptional aesthetic value ani ce: trle,..ents the Burr ur,cTn,
reside;ti 1 area.
�t
Y' The iti:t ," Or th JFE,'l(' c and i: icneck F.:ve'rs art 1c.. tC p:-,r c:.a', ty.
• Thr ,' ,;t t'jc � "n,j a r E.z: tt.. ex!i i J
3,�ccr 4e. In the vicinity Of the river_ confluence area an ' uC 'nstredl,
there is ir.;rea,ing eV7GenCe of wat::i• Guaii.y oegra. tior. due to the presence
of oil an' floati,^ debris , c :r
a—ears ,
ri The lcwer Sh ll ;:kc i.iv; a, ears n be the
prineipal source cr t►:"is degraddZion. life rivers L•rc classified as Class 0
1 Streams by the Sate of New York.
c
r ; 4.
c
i ^
� w
x The hic'lly urrjrized setting has lir1ted t.hr! aouatic resource-1 of the
Sheldra} c and ro-ock N""_rs . Thi prcdcr,inant fc of a(,uatic organisms
consist of hotto.; f,i�;n,a or her,t�os , flor. ar, zc)c :';. :;:,Cn. Tf-csc torn the
basis of the food t: for hi�ht?r life iCi_^ in.lu�Sr.� vari
_ cu, ish species
which function as scCordary an.zi tertian^;' cCns;.,crs in t? ac:u- !_c ecosystem.
' Dominant ;C,,.:,ic •.1:croir.vert^5r3tes ir,elu .. Oligcci .:ete- ca-rth; ) s)
ar:d Chircs (rl_g;: larvae , both charzcter•istic c, sic';: r ;,, fly srea. .s
wit,i r,. bctto_:. aril., Orc�n.0 c'e.rtt;![ , The ti^r�r �` i.rc�:C �i �,�,r ;u�ports
: a rc'":: c:iterSc b c n t h i c faunh i c h rci sects ir..Prc,v c-1 1:'.1.er c-.—aIity. Aamphi'pods
(Scuds) , 6'astropo s (snai 1 s) , and Isopods (SC',. bins) are fo::r,-j :Bare.
Tr;_ f'S erg resourc of the p-c jcct area is sc7ne:•:h:t l ir..i te:.. Fi e hes
present are pri^arily pollution fnlera The most fishery
resourcF,� are o,- • ,,e 1 rr suer
La K? �' . tit Uv;tre .•i Ccservcirs . Fish pr:Sent Tncluc`e caro , .rrira SUc!-
blyill , pu-pkin_eed , A::'.eri _ n eel , an:, ar. assort-•._n� c; r,r;r,c..r; ar-1
w �
shine;-,,. upstream of the nr,; ;: ,led p��cjezt are fond less pc , l;;tior tolerant
k species including two ir-:.ort%:: aar'`.e'iS!' , the bass arm chain
pickerel . These fish could r1o:'e do,,nstrear.r with ir-.prove-ent in water quality.
Lack of access and urbanization restrict angler use in the project area.
!�
Some fi sh i nq taI:e s u i ace in the ''.al,.aronec►; River pri.. ari ly at its entrance
to 1a,-—oneck kartor. An;ler u=a of the Sheldrake Fiver, however, is nor-
exist unt n at best extre,,.eIy 1ir:.itcd. 'i-,_re are no E:ro'.:n rare or endangered
spe:.ies of fish or exceptionally unique fisnery resOLrces in the project
area .
f Due to the present intensity of industrialization and urban develc:,•ernt
'y.. w tIli r the protect area , th? l i ,i tc.1 a quc i.•i c resource= of the ."w r�.:e and
• � - .3 r•" `'^.c_ r' A f f+ v.�p V �., r v ' ms's
t, ., ar ..• .'i, r,iv rs cann.o� C e•..._cte to i; ove sic if lean ,l , i t.
-= N zbserce c` the Crcpo_ed projezt. Sc,e �r;:rc'rement in �zter c- pity can
be anticipated as new ?ws rEG::l3tir,g the discharge of into
watet',: ijs are irr•ple :;ented. in turn, aquatic resources Y:ill hEr :`if , but
' Lo rrh-t dEgree is un"-.nc,,n. Hov ver, the potential for ir,provirg er
quality and increasing aquatic and benchic habitat is great ar,d cculc be
reaso^..'iy achieved by including the appr,prilte mitiya;.ive procedures into
the pro^used Flan.
.:i..y.+. C
T L err a; ..r-i
..
The vegctatior resources within the 1'arnaroreck-She ldrake prc"Ect area are
generally acini natce, by varices ►':et i and trees and shr::5s along with nur:erous -
climbing plans a,.' wildflowers. Types of trees pr;_.gent incluua weeping
Y
i
5.
wilhor:, blacl V:i11.Ct:, FLwillm,,, svcat;Cr,?, re•' , ,Uc;Jr, and
Y ``.,.,
silver rade. r•cd-asicr d . . o.��, s::�ot`i �: 1�^r, r•;hi ,e ash., green esf. , and
white, r•2d , and pini oak. Sh%L; specilCi in;lud:' rr:arsh spiC^I.;ushii
si-;cet pep;:cr, ; sr , and r%iicb rry. Trt:i i irr-. or cliCiir:g ; ., its and ►•:ild-
flo::ers inclu{e poison v, ri ;erbsr.., gra ,C , :' . rginia cre�: ^r , h'�nc;suckle,
bcar.�err;, ,end si:'a-� and r�Jl �iT'lora res -. The a' p ant sr,'-cies
pr•;;';ide ;'a i j-ib�c food, bre::dir , e r' nesting cover to an a;scrtr:ent Of
r urbn wiles? . rL. There are n0 i' ^
.r? GC er'c -r_d S: :'CS 0i YC "tiCil
y in the project area.
The variety of terrestrial ha:titat along the he ar ' .ma o e
S. ldr :e ane �...,, r r: cr;
Rivers Su^,crts a c^._'' te t'-:e ,Prc;CrCe of U-b!nilatien, The
CIS =
.Cr' t ie iC.t C1'vji C i��..ti t :v i.. Sr_CieS to the are: �;..OnG
the 1ArC^r r',: 7:11 S , the
1•'•1'• C' 'r i' ):-�:. i � ^rte rrl rte; i ,•7 ..�_..-.,n
$t i _. ... , rc('Ci:�" , ! _ �•. i'ri I:h , Iii., a:, ..y SC','Ji i c _ in
the :r�, czt arca . T;._ EIS also, iden l Ticd 72 h4rd -';,2cies o' 1:ni_i: 4, are
prc: 1�
`-t -c—C.-S'_rs in the p-cJ t area. The m _ cc7.7,or. oi.scrvcc x.7.2e S
M.' � -n " •e ar r. � ,�'�. �� 'c ': n. ter.
Y;ere ,..u , ?ard , Canc.�a Soc-e, rr. riC robin, re., •41' iC_ i. .ir .,
$7_rrC't� SC^ 7 sparrow' A7,cric&n C"?d2 ir�h '"r n C ter Iir1^ anG
cor--7Cn crc e. An assorti~ent o-F rep t,' ?es ani' G^p.hib:I ars ins udin t:•,e
easterli -t:,X tu!-tits. , CCr:T^r. Sr:,C?'^^ turtle, eas° ''" garter sra�-e, n'^r'Cari
- toa. ;;,ring; Iceper, marbled ;ala-_mrc r, J ;.h r t: k.y sa?;:^3.", ,`' are
and encs. � '
al s', orpser.t. No th►'ea gene ; or encs n-_rcc soecies or tri'wl . "- " veli r.ed
by tee En.:!^-_red 5:)ecies Act of 1as a_cr::•cd, o- the York State
F 'ental Cc'iS2rVatli.^. La-,:, are /:^n ;^ 11:o lnrd�}it �h:
n V ,r
:he fe'lcrar ?y endan.,-erc.;.' A. ricar; peregrine falc;;n anr- t(e state
os^rey may visit the prj;:c: area as c:.C_sional r-..iCrants
Y
,. �t S .�
-,� •�o h;. , • i oer�,.iLted ;n t^� crc� ct area �;' tc:•;n orcir.3rC�. ,^_
'y n .`:_ hr �r ^ -� t . ..r �r' - n• _ r n- is
area .0 _ , _,,. ;�: , afT�: S1C!ii icor t C-- - tL.. �`2S ^ur' �;. _ ? C�__ `;a . C'1
end ="v i r -.-c 1 educati_n be•:ause of its ;rc:;isi i tv to a l a: _ Fc^�-
- - laticr ccn.cr. r;IcL-..siriy 1 r',t?j' tC i . .._ ,:t.'f
17Ci�c.Ji �C:,CC ai loci ^.i al'o^!r both ',•'vei _ s'nv 2 �'>L:';her.2
hatitat arras nav b_ fOLVId alc'nc the lc.:e- She;,, -Z;il:e River test c-
Rc5; u; tc :he vicinity of Ret.'+.- Aver ;: and alcr; the "F,-.:.ror._ck river
ea.`t of N, Earn' "venue. Sier:ificant wllGiife I.cG' ' at diSC e>:iS�$ In the
for-, o1 unZfn -alc:pec! lanes adj,:cer_ to the rivers ane the Ne:. EnCiar�
a Thru,,:ay. In addition, the' nc%artk onni-, Briar an:: :'inoot Country
Clubs a?ong w h the Sheldr'a c• tiatre Fra'1s arid, Saxer. good. Cc::r,try park,
affCr-J a ddi iIt-io,,a nabi4%at a r c d s ircm `.;i.ieh a Variety of wi iii ie
can be o *-: r vuui and appreci a t;d.
_ a
6.
t
Project Impacts on Aquatic ar,d Terrestrial RCSOU es
r. .-
Aquatic Resat.rccs
The molt signific,nt implacts on aquatic resources are those a,snriated
with strear,: charri_lizaticn and; the prc,,>o:,cd Fcnir .re Poad diversion
tunnel . Sc7c 12 ,23C linear feet of channulization is pro,.o,ec for the
Shelrra►:e and ":-•.rrineck Rivers . This a:culd remove approfiinately 152 ,000
� SgL.err C - {,it at ,rC7*. �� hL,nn� •hc twcu r41vi-•r. In
c. _ •CC . of a�,:a�1c %,.u1 ..4 � � �.. � .. _ c..�.., _ls Q� 1.1 �_
additic}' , excavation will increase the sedi:.ent lead of each river sub-
stFntia? ly due to resuspension of bottlj,: sedir'•_nt;: and eros ion fro- banks
strict,_;; cf v_ ,eta1. ac^chic o ganis- and thl;i►• habitat will be
des.trc:•_d in the ch:nneliZcd sections . Fish kills are e>:Pected during
L
xcavation due to the increased turbidity. In the lrr., ter^, charneli_a-
tion w;ll re�uco the di�ersit`.• and cerrv;r„ capacity o- ri ,rs for
fish ar { other aquatic organisms.
1hr F2: 4.;-,ore Road diversion tunnel will divert the flog from t^e lower
p
Sheldrake alae River �o the !.est Bas In of Harl or
`_•area-`le;; in the le;rer reach :ill be r:air,tainEd by incre-c-ta1 runoff
only. Sirce this portion of the Sh^idraE.a River has already been
chanre; zed and its fish and riildlife habitat severely &,craded by urban
and in�jstrial pollution, the diversion tunnels ' effect u,nor the ratiral
resources of this reach wi 11 to mi r.imal , He:«ver, depencerce or incre-
mental %noff may not adequat^?y insure the surv4,v:1 of existing aquatic
• resourc_s. Therefore , provision should be made to alto-;: score strEaMflew
to cor:`.Irwe dc'-,-, the river by bypassing the diversion tune• .
Y . tr c r n n •.O n n
The cr.:s 1„�io,: of the Fe,.i.' �•►•e Road diversi_�n tu..r+el can zl5o be
;.: if expected to affect sore chF:r,ee in the sal ;rlity balence betwce,. t^e Fast
and is?$; Eas ins of F'araroneck E+ar�Or. The d?vCr,iCt tunnel . : l I ir=1'ea$e
;r the influx of freshwater into the i.;est 5;;sin reser'Ting it lo..=::•e salt
conce,n.traticn.s. Concomitantly, operation cf t!1-,', di.,ersic-n ,.ti: ..=
acorea_^ thn influx of fresha:�t��r ir�tc the East Sasin resu? air.c in raise,'
salt con:?nt1•atic^s. Subse4Jent char es in the diversity and ab;:r:dance of
'# suu:'eri 2^t and emergent vecetation, plankton, nekton, and benthces in the
two bas ins , are ar.ticioated. l;nfert;.na.ely, in Licht of are other point
so,.rces of pollution entering "ar.aroneck Harbor, t.,_se changes , whether
.' adverse or beneficial , will be difficult to ascertain.
Ter+-estrial osourc,-s
The most sianificrnt impact on terrestrial resource! would be the removal
of large anourlt:> of bank vegetation as a result of channelization and, to
a lesser extent, construction of the di�8rsiori tun► ::1 . An estimated 6
2
� • r 7
/ .
t
• acres of riparir.n trees and strear-;ic; shru`', , ;,rusFi , ars rrJ5SC5 wou?U be
r lost. As note above, this .Xuld clave deleterious effects 0- aquatic
resources . Strcaf _sick e r c t 1 t I o n p r o v i n and cover- for r;rn_y wildlife
r i 1 r ,c f l i r h n r
speC1CS , [_i+t'cial ��' il(�t!i. 1C ..►1i_�.iC.,. �2C(r ;Ct1GE? In I����UI,;.,1�. .5 is CX,1CCtCd
particularly in 1?rrii iiiii"Gi1.1tC!j downstrearl of clianneli7c,'_+ reaCiics . All
dC+7`iti %ns /ins'. ccrta4n rc,ntilcs %Will re muskrat,
min ra11al-/d , <<,n d;: rc`OS^ , anJ rig arl%In „,iti: ird5 Yrlll alio (:Cel ink
and G15tU1'Ocn-e Cf the aqua's c CCv •j ,,:i 11 z lsc, hp?? seconc ary
Y cts n.r, ;ildlif;. inc1udi^n lo:.s of habitat anal. food SC'u' t+: AGt•ic
ir.sCCfor icc, ccu1_I L,ccc"-a ung /aiii%IC to and other bird: .
St►'e E,1 t,2r4:'r.:i i;l i 1 a 1 s CC^,rade the aE S`r:Lt1 C a" r,- aril C Of the area and
r'
0ppo:r vn1 t icIs f-)r non-ccrisu,::'r:ive Wildlife LSe i':i I I be ►-ecuceu.
Plan of Developr:-ent for Aquatic an:i Terrestrial Ecosyste-s
-Th? i. _ ,,••!' i�'...;, _.t r:+.;i..,,v r,.. _,.,a�� a.Fr1`4•r l.0 ;1• / nr -+ .!. +1 ;cr. ?Jr .�•. _rrJ�
t�lt!i cel CIiC.. io�. TnE_ Fizz". cn_ 'I;i Iii fc r'riCe carr,:. s",''',^.c~t the ex-
t E: iV ril..'iZ 61cn p1GJVscv in t, 15 rr--;C.... 4r,v out irv. _ ' 1' V. ,c•ns
1ndlca7e enc.- c h 3 r.e11zaY1cr Is nog n e c 1si-,i t"dcq,L;a fl ,,.,, :'C. ..ec`. ,on
can to Drc,vidPd by exp^;•`vir;^, t`: s1Z aind exter,t i exiit'.n- T '
This al tem~ a ca be r_ �1 .3 J ` :,;:er cost t'-an
�i r e n 1, aLc,,.:, i� ICV � � a l
and less c^,.i1-o!,r.'en:al d�crcda.icr. Flc J', r i CGrs.- .• -d -n
ecr'iier Cc t+ , clready exist wits;in I'. 1 of tfle t,a'"?ronec� Fi` pr pr sect area
_ and Y.•. -I;:r ^„ tio-� G• t'' _ :helc+rakc• Fiver. Tha eleva`.ion= -rd l `^c
,.� e �h, or l
these f1C!o:.r.alls Car, be easily eypar: 1'/ith,-:t dis`.urbiro th,c• Eli-,V' "I
chann:l t:t'c- or rerovin.(� riparianurdCrstory a n� o:er- :cr ,e,•.t .tion.
Facir•_; t: i fr}.,C^ ' fleal•.:3: Iis with nrLive rocs` 1• :l I help -l'-C t!'_
area 's 8eslli,`C appearance.
_1C
If ch n=! icaticn is the or?y solutior. to fl:.edinCc-1� ata 5; c site
i ,
0r'Cce :U!,:S t;;z_ call fcr Iirl:itin7 strir ---, exc•n to
0011V -n nr,�. '�i,c , raintai'nir ,- r•Fa-i,:, o'�erstcr arc uncerstcr � �e�_ � tion
s, a C' Gt; Canis.
� ecu :ai,;rt 1,r... .;r species s`i^uld b_ lan~ed to res`ora `�i� Err
sr as closely as possi le to �yl �s . Plant selec i—s
a $hrov i V t= coord i na ted w i 1:^ the New YOr� .` L.i fin Derart,^en t of EnY'i i'Or c'• tdI
Conser% ti _. Costs for this tree and shlue Fldnting program are anticipated
to b-
Stre:.".tanks should he mulched and seeded as soon ?s possiVle after con-
yy
stru.,. C': to .":itlydtE tf;L' ?Oss .O` terrestrial hGt,i a� a^d t, ai ie':1at?
pour al ^r0_•icn. During cons! ructi,^ , control r'f:d ur::s shcu� be
incorporated to decrease any adverse effe(.ts on wai-.e:r qualityin the
immediate ccrnstruction arca ani, dc•I i;trcam. Use of silt anc:,u;' 'ui•t,idity
_�• curtains would be appropriate. A total of ,v4ij 4 3 is anticipated for
_ these erosion control pro_cd..res; ;? S,G� for m:rlchir,g and seedin(i and
$3.400 for a program of silt and/or turbidity curtains.
=f�
ti
i
1
Natural strew m. anue+•s sh,;jl:i tc rr:in,,iinc in X11 rection, of beth
rivers tirher-e flor_d:;all cor�tructicn or ch.;nncl r,)dificL:tion i� anticipated.
At these specific sites a:hwro charnel rrodific,tior, is nc•:e,sar--, construction
of a c:canderinc; U. �1,c lc-.-i flo,. pi iot chanrel alcn tri r:or_ densely
ve etdted ri s encc;:raoed, unless i . , ,: ' r., L i ,
r •.� r rK i was t.�r_ �c ,�..t,. �,c ter. .s on the
inside Or a stream: Curve. Costs of 11 ,3uG =hc::ld be incorporated into
thtl proiect plEns for this project design.
t
T�!c ir.'.: lyir-, fl;;odplain ar^as en `he Slr_'ldrai:u Diver do'.rrstrei of
`' �.evere Road tc Fenir..ore Road should not be fil1C- hccause of their high
.'iUIC :.Citi value. It i$ SU -, L U t,i-t t�° retdi'iln, 4:311 proposed for
L:._ Fo, :.tte A er"r ,rea be moved 1 r^ " d ar s p ssi:;1 `hC.reby
�� �.._ u L ..�.ui GS 'ate � C� �
_cu,• n tti,s aand l ir~ - ig r: hcu s the 6 d
"
to fill in the finodjplain. Anticip!t-Z' costs for thi" construction
J
est:?, total SG .M-.
;he Fenin-^'•e "cad diversion tunnel sf ,uid not dive:.,-- the total flow of
�
the }; er reach. of tri^ Siieldrakti E;iv;--r i., _ t.1-e ci .er;io tu. 1 , l.
suc: ,;, th t z ., .r„ctu. e to devisee wou d divt only t:..:t portion
of 1�c f1C flc.: which is it excess- of the lob:er Sheldrake diver's ra:_:'"31
:•zn�.:f�;i i ca:acitv. This ti oz� lu alleviate floodinc downstream i:bile still
�
rese--. ung the fish and wildlife resources that remain in this section. In
r'• addit';`n , ma4,ntenarce of barkfull cap city will dilute the r.,r-. y p0ir:
sour es cf acilution in tf;, 'ower Sf. c.;-eke which might oth • :;ise stagnate
: . and fr" ,' .ce noxious odors. Construction costs of Si1 ,0r0 a+ e anticipated
f0, fe-,tore and Operational and rr„intenance ccsts are est';G,ited t0
rur Sl ,J'0 her year.
Y All cress of the }landronecf: River that are prorosed for filling should
'• inti t_. • b_ floo�.•ial ied as ;ar landY;srd as pcssibi� so ~�-at the fish and
wild' —"c;i . reso, ices assucia a—' with these are--s e;.s ar;; :. -eservez: . These
9i fivoi. I . sr•_vii,
be facEd N"h nit*'v:. .'•c:k t0 he1p :restrVc th:e aria 's
cert I. t iC qualiti s. Cc.st of $60,003 are anticipated
-•e
pro-
tect.ve measures.
Log a^j rock crib dams have been mentioned' h;.• Cops person:..^.el as mitigation
i r*easures fcr the ''a^aroneci; Ri er. Our inoesticeations indicate that areas
*, suitable for the place..;ent cf these structures include:
.•yam
1 . h^proxim5tely 175 feet dm.mstrea^ of t•:infield Avenue;
t 2. The reach tetwee„ 1:.7rren and Traver ^':e%es ;
;. Aporoxir:;%tely 100 feet upZtream of the Nei-, Englan: Thruway;
-1 4. Approximately 20� feet downstrearr of the First Strcet bridge, and;
S. Approxirztely ICO feet upstream, of the r.ew Hillside, Avenue bridge.
r
i.
(_1ur -investica"-r_ns also indicate that an ar-••;, ,suitat�1e the placement of
a log and rncI. crit, din, exists on the Sheldr.:!ke Rivcr i. ,rdiateiy upstream
of Ogden Avenue. Thi; area , currently/ prc. -_;c;' to be filled,
has high
biological value and creatior of a pool would increase its ecological
diversity.
The artifical peels cri3tcd by these lairs s`+r:;;ld be approxir;tely 41 x 20
f-22' in Slee and 5 feet Ge^,. If &--Annei r'^d `icati;n 4; required at these
si :,.s , ther, ,pill;•:;y; from th-1 pnols should, cincor:lunction with t.�C 1c`•. ficw pilG". Ch;,nn:!l . Lzrce bnwldcr. t:nd/cr r! b;cr- be
F1aCe:i in the Fools to Create and y;versi•., I-o" ^ h;--bitut. E x i , tr9
str°;,- cide ve r.Ctailu , s:.-)uld he F.„•1n+aineL or heti? i)- .1 for �G TEft
ups tr;:,;. ar'' traZm of _Iit;a SC! 'jCtures . A t 1 eStl!-,a'-?d 5 :2 ,0'',"D ,hou1d
be i'corporatnc into the pro e-t plans for ti,ase :ri tigati or
, c,easu!-es _
Ing 1 �`riV !•'., ivr�tl!J7! of bill: `C rl`l�.erg.;, v, ., .0 , _. ..:��:Cf
and Rivers within Collm".,. Park sh; i� ro* be ircl;;-,:d in tl;�
} Se ECted plan. Our d r -,r. r . a-r�:
caul., +c:,4 _e n.� h3,-,--es r. ,r:rc. � cs
tha •ece': v? SlOad der;a�� wlthir. t!:i°. SP.Ct10” Ther furl, YE SUF •, tr:at
no 'VStif !CatiCn EXiStS for the destr'uc icn t^i`' ! � �
aq;:ctic and terrestrial habitat. in ad-Jitlon, o^.rG,"vi! G` the FL,:•• ,-ore
P.o.d da:er! inr tunnel 011, relit.ve a portiar of the flood
har_ar: in t::is arta.
RecoT7cr.dations
R'e recC) ..• that:
1 . tt••_ e�:tensi vn cnarnel i zati cr, propnsed for this project be
aGc'don;:,d Adec•uate flood protect Gn Car, be r'+'04'i' @d b}' ei�^cr!dli+9
the size and extent of existing "lec ...a' 1s. if f
tic:^ is the only sol uF;cn tc fie_•-Ji a t a sceci ,-ic si .e `ile
k rC,Tv'�'rlI of trees ..n S! i' �� ,h(?J�.. LE i!I:n1C:' Ste: Ar_ 1 �"_ of
trc:_ a-:d Shru:... :"^uld b•,`! rir, t �. r ..c . `,1_t.
has the l eaS L amowJit of v;� tatl '+' i n any .CL' l ar rtaCi; Of the
ri-,er. Those trees and Shruhs re",C'`.''d ciuriny cnannel alterations
`� i• sh,, d be regia^ed with Cquzi.:alen'., iCr-s and spec-it - haVi^f�
high wildlife v;:lues . T',Xse plar;t selections shou*cd be coor-
Jrdins-it;-d arith tho rye.; York State r.!epar0;.,,%nt of Cnvironmental
Consr,-vation. Est ir^atcd cost.
"'. Z•
slit and/or t;;rb; dity curtains bac usz•c� 1r bot`. rivers and along
s
their bL,',Rs during on5truction to minimnize my idverse of ect
`= On waterur l 1�_ �1 .d � r
Q .,v �G ro.••i'.Gl Sall erU5i0i1 a rnto the water'iiays.
-�= EStin�•�?;.�� cost: a ��'.CJO.
�{
r -
-
a
4
f!
ti
t ' 10.
f
t
a t
3. all streomt arks be mulched ind seeded irr-gidiately follo,.ving
enrstruction, section by section, to alleviate pu_ential
r
erosion. Estimated cost
: �'fi,GCG.
s _
4. all natural stream neanders be maintained in the sections of
� the rlv^r %.here fioodwail c(7n-I+ructlcr. or Channel r,,:•.,:l fi cations `
_ are anticipated. At those specific sites %rhere channel
P r,odification is necessary, construction of a mcanderir;r U-shaped
- low fl .-,i pi'ot char.n;}l akin= t;,_ more 4
bark is enc^'.jraged, unless the vEgetated ban%: is-on the inside
of a streafll curve. Estimated cost: $11 ,300.
the low lying fl;,.,,,plain arca on the Sheldrakc i , _r c. . ,.~carr,
y of Revere Road tc� Fenimore Ron
d not be filled as plarnec;
` because u` th_ir )-.,ch biolc: ,al value. The F'yette
A%,cnua retaining ;;al i , construc.tea: as far
would adequately protect the fe+q houses that occur in this area
- ' and at the same ti-e ~reserve significant aquat;c and terre5-
tria•l habitat. Estimated cost '�6 ,70.
Rl 6 the Fenimore Road diversion tunnel inlet be modified to divert
only that portion of the flood for,:; which is in excecs a` the
lo%•rcr Sheldrake River's natural bankfull cdpacit ' This will
ossa~: the survi%-al of the fish and wildlife resources th,--t
remain in this section. Estinsted cost: $11 ,000 -or con-
..s s
structiC.l and S1 ,000/year for operation and mainterAnce.
-t; - 7. the prouosed f i 1 l i nq of low lying areas within t^e ;'O.7;!r•oreck
r
River floodplain, be abandoned and instead flocd•;;ails be
constructed as far landward as possible so that prcpertics
are protected and floodplain habitat is preserved. _stirateo
• cost: 450,000.
-"
S. log and rock crib dam be CC^etrJ:;Cv in tti"_ 'la" a;r;`i.
{ Sheldrake Rivers as previo;:sly descritec to help cr�ance
fishery resources and to mitigate the less of valu.--lile aquatic
�- acrd benthic habitat. Estimated cost: 412,000.
4
c the plans for relecatiry the confluence of the ShcIdt
` Mamarc:reck Rivers within Col urr5us Park and the hu i l i r,c c•f a
.. .
^' parking lot at this site be abandn-eo. No hopes o • pf ere*'ties
.: that rec:ive flood dar^age could 5e located in this sectio;,. is
.•s
' •- � l 1 .
addition oR�'r,ition of tfie F r,i:�o: !?•:.ad divcr,i(,-, tunnel will
re�!uce the flnrr of :,�:: �heiur�I:e Rig: - i�.tcr Cc l: ,u' Fla rk
thereby relieving a substantial portion of tint_ t lood h,,zard in
y
this area . Thcr,-fore. no justification c;:i;ts for disturbing
t`c arca 's Yalu",ble squat?e and tcrrc-st.-izl re-sourc(_'s .
A.1 ? constrUCti(-,1 Should 5P Cu^.:15tor - with Pr�•,lu_'�,; Cd:''..�r' s t>•.ecu ive
U Lr vn F 1 . �� i, kt n, y`. , F• F. S ed ir: th2 Fr,lc„ u ! F,"115 •-
�c�c .a � a a -.e E: u.I� � r, � c ,
7
i
Plf'ase advise this office cf any action,, taL:en on our rc'c ,-r rdl:i a"
plan of c;cvcicp--cnt for fis! and wild resources , if yci r F..-c.. _ .
� ., , plca5e Ile`:lf)' 1!S SC If neC�SSGr- we Can revue cr a
znG on the sub,j_ct UDIESS We hear Qt:`:Crt'is:, , it is exN,Ctc� tr.:,z cur
rc:;:n7endations will ;2 in:crpnrated into yot.r next r!''.a-C.Ct plar.nin nh,. se.
If wC ear, t;^ of at%i f;;rt.h ptaaa ccn_a:t us.
Sincerely,
~, Paul P. Hamilton
A Field Supervisor
i
UNITED STATES
DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE
-.�,•
100 Grange Place
Room 202
Cortland, tilew York 13045
October 16, 1978
District Enaineer
Clew York District, Corps of Engineers
26 Federal Plaza
flew York, Mew York 10007
Dear Sir:
This is our report concerning the impacts on fish and wildlife of the
proposed flood control R,easures along a section of the 6yram River
located at Port Chester, New York and Blyrar, Connecticut, part of your
Westchester County Streams project. The project has been authorized for
studv by resolutions of the United States Senate Coc,mittee on Public '.:orks
adopted- Septc,mber 14, 1955, and November 14, 1955, and with a resolution
of the United States House of Representatives Committee on Public .•:or•ks
adopted June 13, 1956.
This report is submitted in accordance with provision of the Fish and
Wildlife Coordination Act (48 Stat. 401 , as a^,ended; 16 U.S.C. 661 et seq)
and has been coordinated with the Petit York State Division of Fish and ;•;i 1 dl i fe
and with the Connecticut Department of Environ.m.ental Protection . it supple-
ments our report dated May 2, 1975 by providing more detailed information
and mitigation costs.
Project Description
The selected plan consists of a combination of levees , floodwalls ,
channel r,odifications , and floodproofing. The existing channel of the
Qyram River wiil be widened and deepened from a point of 400 feet down-
stream of the !.;est Putnam Avenue Bridges running upstream for about
2,000 feet to a point just downstrea;r of Pember.vick Lake. The codified
channel bottom would have a base width of approximately 40 feet. An 800
foot floodwall will be constructed along the t•:est bank bet:•reen Transparent
Fabrications and the Homelite plant. A 3,3£5 foot levee will be constructed
• on the east bank upstream of the Homelite parking area to Rex Street, which
is the downstream limit of an existing Corps of Engineers Project.
a
2.
The project area is located in a hiahly urbanized and industrial setting.
Although portions of this section of the river are aesthetically pleasing,
its urbanized and industrialized nature has eliminated significant fish
and wildlife resources. The majority of the project is bounded by private
residences, factories, floodwalls, and large parking lots.
Description of the Study Area ,
The Byram River Basin is located principally in Fairfield County,
Connecticut and partly in l•:estchester County, lNew York. The basin,
draining 31 .0 square miles, encompasses areas in the To-.:n of Greenwich,
Connecticut, and to a lesser extent, areas in the Towns of North Castle,
Bedford, tJeti•, Castle and Rye, New York. The communities of Per•:berwick,
Glenville and Round hill , Connecticut, and Armonk and Port Chester,
New York, are either wholly or partly within the basin. The watershed of
the Byram River is roughly triangular in shape. Its maximum length extends
13.5 miles in a general north-south direction, while its width varies from
0.5 miles to 4.5 miles. The watershed is gently rolling and bounded by
ridges. The Byram River rises in the extreme southerly section of the
Town of North Castle, New York, and flows generally in a southerly direction
into Long Island Sound. The average slope of the Byram River is approximately
20 feet per mi.le. The downstream portion, 1 .3 miles of the river is tidal .
The Byram River is classified as a B stream (primary contact recreation per-
mitted but not human consumption) in the project area by the State of
Connecticut. The State of New York classifies the lower, freshwater portion
of the waterwa� as a class C stream (suitable for fishing but not drinking,
CCLkk% \0.Xv OV -ood p�ocE�srh�� �u1 ro_�S, G:,a nr%r\aru carr\ .�� Yev,CC or� ,
Aquatic an-d Terrestrial Resources
Aquatic Resources '
Fish species- found in the project area a:•e Tergemouth bass, Micrcpterus
salmoides , alewife, Alosa pseudoharenirus , American eel , Anguil a rostrata ,
com;,,on shiner, ",otroris cornut;:s, white sucker, Catostor•us cc7,7:•2rscni,
spotted shiner, Notronis huascnius , redbreast sunfish, Lepemis auritus , and
golden shiner, Notemiconus crvsoieucas. The limited fishing that occurs in
the project area takes p ace to the Pemberwick Lake section , which is the
upper limits of the upstream section of the project. Belga this section
heavy industrialization and urbanization with their associated pollutants
have degraded portions of the river. As a result fishery resources are
minimal and presently little fishing occurs in this reach. A few common
shiners , Notronis cornutus, and I'w,erican eels , Anguilla rostrata are presently
found within Ms reach.`There are no known rare or endangered species of
of fish or exceptionally unique fishery resources in the project area. The
•
3.
limited aquatic resources cannot be expected to improve significantly if no
project is built due to the intensity of urbanization and industrialization
• and their associated degrading effects upon the area 's limited resources.
Improvements in water quality can be expected to take place due to the
implerentation of recent laws regulating discharces into waterways. This
will aid in making the river more suited to aquatic resources but to what
degree cannot be accurately calculated.
Terrestrial Resources
Plant species found in the project area, despite the highly urbanized setting,
are black willow, Salix nigra, smooth alder, Alnus serrulata , red-osier dog rood,
Cornus stolonifera , sycamore, Plat-anus occidentalis, red maple, Acer rUbrurr
pin oak, Quercus ealust'ris , poison ivy, Rhus ra_lc ns , weeping �,-Tix
babylonica,b ack cherry, Prunus serotina , mJ tai-?aa rose , nosa r ultii'nr'a,
riverbank grape, Vitis riparia, Virginia creeper, Parthenocissus Cuinc;ueroiia ,
and an assortment of grasses. No kno►-;n threatened or encangerea species of
vegetation was observed in the project area.
Wildlife species have been disturbed by local developmental pressure. The
Byram River inathe project area supports the follo:ring wildlife species :
opposure, Didelphis marsupialis , raccoon, Procvon lotor, striped skunk, iephitis
mephitis, ;.00cchuck, t:arTota r-onax, eastern cni:,; Taenias striatus , eastern
gray squirrel , Sciurus caroiinensis , deer mouse, Pero-.vsenus r•aniculatus ,
meadow vole, Microtus penns:'1van icus , black rat, Ratl;us ra r-tus house crouse,
Mus musculus, eastern cottontail , Syivi1an-us fiori danus , herring gine , Larus
argentatus, Canada goose, Branta cana~ensis , mallard, inas plat';rh,irchos ,
ab1 cack, Anas rubTrioes , ;•;ood duck, Aix sppon.sa, American kestrer , t•a7co
s arverius, rock dove, Colur"5a livia, mourning Cove, Zenaidura r*acraura , Ruby-
throated
uby-
tt ro�ummingbird, Archilochus colubris, belted kincfisner, "ecraceryle
alcyon, red-bellied woodpecker, Centurus caroiinus , hairy woodpecker,
Dendrocoous villosus , Do4ny wocd ecker, nubescens , purple martin ,
Progn•e suois, blue jay, Cvanocitta cristata , ...-erican crew, Corvus brachvrh_Ynd_ytes ,
winter wren, Troalodvtes tro� locvtes , ^ioc ncbird, Nimes poly^OL OS , roJin ,
Turdus miaratorius, woog tnrusn, ; v ocichla mustellna , ceaar wax-eiinn, 6orbvcilla
cce rorum, cor:,on starling, Sturnus vuIc:iris , yeilow ti•rarbler, Dendroica
petechia, house sparrow, Passer de;resticus , red-winged blackblr ,
pioenlceus, conron grackle, L7 scuiu oaiscula , bro:m-Treaded cowbird, "c othrus
ater, cardinal , P,ichmondena carcinalis , nouse finch, Carpodacus mexicanus ,
tree sparrow, Spizella arborea, field sparrow, Spizella pusilla , and song
sparrow, Nelosoiza r•elodia , American toad, tufo ar,ericanus , green frog, Rana
clamitans , sprinq peeper, tivla crucifer, Eastern box turf e, Terraoene car7oina ,
common snapping turtle, Checivc:ra sercertina , and Northern waterer snag, 7ot�rlx
siped�on. There are no known trireazenea or endancered species of wildlite ana
p al nts or exceptionally unique habitats in the project area.
a
4.
If the project is not authorized for construction, the area will remain in
its present state which is highly stressed by heavy cor•,n,ercial and residential
urbanization. Mature nut and fruit producing trees and shrubs would continue
to provide food and habitat for the various species of wildlife of the area.
Wildlife species would remain at their present levels for the areas habitat
is at the maximum carrying capacity for the species present. The aesthetics
provided by this vegetation and wildlife will remain.
Impacts of the Project on Aquatic and Terrestrial Resources
Aquatic Resources
Adverse in'oacts of the project upon aquatic resources would occur due to the
channelization of approximately 2 ,000 linear- feet of the 6yram River at an
average ti-J dth of 20 feet. This would remove 40,000 square feet of bottom
habitat such as rocks, boulders , and snags that provide suitable habitat for
aquatic species.
Removal of streamside vegetation would cause erosion of soil materials into
the water:ray. ,The resulting siltation could cause deleterious effects upon
the agjatic species in the project area and for a considerable distance down-
stream. Silts clog the breathing mechanisms of invertebrates and also fill
crevices and pools :ihich are t~eir favored habitats. This will adversely
affect the organisms present and may entirely eliminate populations . The
removal of streamside vegetation will also eliminate detrital sources and
elevate '.,ater temperatures by removing shade. This will have a degrading
effect upon the resources present. The loss of aquatic flora will limit the
ability of aquatic organisms to repopulate once construction is complete, due
to the diminished food sources and preferred habitats.
Terrestrial Resources
Channel widening, alignment, and diking would remove approximately 4 acres of
trees , shrubs , grasses , and brush that provide food and shelter to the urban
wildlife and provides some aesthetic relief. The removal of this habitat
would cause a decrease or elimination of existing wildlife populations from
the immediate area.
Plan of Pi!velcpr'ent for Aquatic and Terrestrial Resources
If the selected plan is implemented, the following measures should be taken
to minimize adverse impacts on the floodplains and aquatic and terrestrial
resources. The costs of these measures would be borne by the construction
agency.
a
5.
The removal of mature trees and large shrubs should be kept to a minimum.
Any removal should be restricted to the one stream bank with the least amount
of vegetation in any particular reach of the river. Trees and shrubs removed
during channel alterations and levee construction should be replaced on a
liberal basis with trees and shrubs having high wildlife values. These
plant selections should be co-ordinated with the New York and Connecticut
Departments of Environmental Conservation. Costs of S67,300.00 are anticipated
for the tree and shrub planting program. The stream banks should be top
dressed, seeded, and mulched immediately following construction , section by
section , to alleviate potential erosion. Estimated costs of S40,000.00 would
be required for this activity. Silt and/or turbidity curtains she -ld be used
in the stream or along its banks during construction to control silt leach-
ment into the waterway at an estimated cost of $1 ,500.00.
Natural stream meanders should be maintained. In the sections of the river
where channel modifications are anticipated, a U-shaped low flow pilot
channel should be constructed along the more densely vegetated stream bank.
A cost of approximately S4 ,200.00 would be incurred to construct the pilot
channel . A series of artificial pools (3) , formed by gabions , should be con-
structed with p average length and depth greater than the average width and
depth of the river eg. (30' long x 15' wide x 5' deep) . Spillways from these
artificial pools should be constructed in conjunction with the low flea pilot
channel . An estimated $3,000.00 would be required to construct this feature.
Some large boulders and/or gabions should be placed on the pool bottom so as to
diversify the bottom habitat. Costs of $3,000.00 should be incorporated
into the project to cover this activity. All streamside vegetation should
remain undisturbed on the banks 30 feet upstream and downstream of these
pool structures so that the full benefit from these structures will be realized.
This streamside vegetation provides shade and detritus , both of which are
necessary elements for the survival of aquatic organisms returning to these
pools following channelization. If-poss :ble and if costs permit ,-a small rudi-
mentary parking lot should be constructed possibly by just widening the dead
end Lucy and/or River streets in Penberwick, Connecticut during their recon-
struction. This item will not be included in our reconmendations because
such structures are qenerally looked at as enhancement measures , which require
local cost sharing and that possibility is highly doubtful .
Recommendations
We recornrend that the following items be implemented in the project plans
if the project is authorized for construction and that the construction agency
absorb the costs of these recommendations as mitigative measures.
•
6.
1 . The removal of trees and shrubs be minimized.
2. Any removal of trees and shrubs be restricted to the one stream
bank that has the least amount of vegetation in any particular `
reach of the river.
3. Trees and shrubs removed during channel alterations be
liberally replaced with trees and shrubs having high wildlife `
values . These plant selections should be coordinated with the
New York and Connecticut Departments of Environmental Conservation.
Estimated cost is 567,300.00.
4. Stream banks should be seeded and mulched immediately follo,.,,ing
construction , section by section, to alleviate potential erosion.
Estimated cost is S40,000.00.
5. Silt and/or turbidity curtains be used in the stream to control
silts from leaching into the waterway. Estimated cost is 51 ,500.00.
6. Natural stream , eanders be maintained in the sections of the river
where channel modifications are anticipated.
7. U-shaped lo.; flo,.•i pilot channel be constructed along the more
densely vegetated stream bank. Estimated cost is S4 ,200.00.
8. A series of artificial pools be constructed of a size approximately
30' long, 15 ' wide, and 5 ' deep. Estimated cost: 3 pools
@ $1 ,Q00.00/pool = $3,000.00. Artificial pools should be constructed:
1 ) At the end of River Street immediately below the cement sill
that is to be constructed at the mouth of Pe .berwick Lake. It
is suggested that the vegetation should remain on the east bank
downstream to the five foot high brick sewer manhole landmark.
2) Opposite the se,,rer manhole landmark with vegetation left undis-
turbed on the west bank.
3) At the end of Den Lane leaving the vegetation on the west bank
undisturbed. , '
9. Boulders and gabions be placed on the pool bottoms to create and
diversify habitat. Estimated cost is $3,000.00.
10. All streamside vegetation should remain undisturbed on both banks
30' upstream and dcwnstream of pool structures so that the full
benefit from the structures can be achieved.
11 . Any construction in the floodplain should be consistent with
President Carter's Executive Order 'Li-96t "publistied in the Federal
Register dated May 25 , 1977 , regarding floodplain management.
) i9EE
The above mitigative recommendations should be included in the next stage of
your planning process.
7.
Please advise this office of any actions taken on our recorriendations and
plan of developTent for fish and wildlife resources . If your project plans
change, please notify us so that is necessary we can revise or prepare a
new report on the project. If we can be of any further assistance, please
contact us.
Since r ly yours ,
Paul P. Hamilton
Field Supervisor
i
e
a
Carbon Copy Sent to Following:
Dir. Norman Chupp. Area �•lanader
U.S. Fish and tlildlite, Service
100 Chestnut Street, Room 310
Harrisburg, Pennsylvania 17101
Mr. Herbert Doig, Director
Division Fish and I.;ildlife
Department Environmental Conservation
50 llol f Road
Albany, NY 12233
Environ ental Protection Agency
26 Federal Plaza
Room 847
New York, New York 10007
District Engineer
New York District, Corps of Engineers
26 Federal Plaza
New York, Ne%•,, York 10007
NationAl Marine Fisheries Service
14 Elm Street
Federal 3uilding
Gloucester, �•lassachusetts 01930
Preservation and Conservation Division
Department Environmental Protection
State Office Building
Harford, Connecticut 06115
Mr. Frederick Slater
Regional Supervisor Division Fish and Wildlife
Department Environmental Conservation
21 So. Putt Corners Road
New Paltz, New York 12561
-` DEPARTMENT OF THE ARMY
NEW YORK DISTRICT. CORPS OF ENGINEERS
26 FEDERAL PLAZA
NEW YORK. N. Y. 10007
� REPLY To
-"' ATTENTION OF
NANEN-Cy 8 FEE
Mr. Paul P. Hamilton
Field Supervisor, Cortland, N.Y. Field Station
U.S. Fists and Wildlife Service, USDI
100 Grange Place, Room 20.2
Cortland, New York 13045
Dear Mr. Hamilton:
This is in reply to the final Fish and Wildlife Coordination Act (FS'.,CA)
report dated 13 September 1971E and prepared by your office on the effects
the flood control improvements proposed by the New York District , Corps of
Encineers for the Mamaronock and Sheldrake Rivers Basin, Village and Town
of Mamaroneck, Westchester County, New York will have on fish and wildlife
resc*zrces.
I have reviewed your final F&WCA report, and the nine (9) recommendations
contained therein to mitigate the adverse impacts to the existing fish and
wildlife resources in the areas that would be affected by flood control
improvements proposed by the New York District , Coras of Engineers. In
accordance with the desires expressed by your office in the last paragraph
of the final F&WCA report , all of the: US F&WS's recommendations will be
considered during preconstruction planning which would be the .next phase
of planning subsequent to authorization of" a Federal flood control project
by the Connress. However, my views and comments on the recormlendations in
the final F&WCA report are inclosed herewith for your information, since
the final F&WCA report along with my views and comments will be attached
to the final E1S for the `famaroneck and Sheldrake Rivers Basin, New Fork,
and incorporated as one of its ancillary documents which will be presented
to the Congress as a package.
Your assistance on this matter is appreciated, and I look forward to your
timely cooperation on this matter in the future.
Sincerely yours,
IA
1 Incl CLARK It. bE.NN
As Stated Colonel, Corp; of Enz,ineers
District tnginet:r
NANEN-Cy 9 February 1979
SUBJECT: New York District Engineer's Views and Comments on Recommendations by
US F&WS in the Final Fish and ildlife Coordination Act Report dated
13 September 1978 for the Feasibility Report on the Mamaroneck and
Sheldrake Rivers Basin, New York, Prepared by the New York District,
Corps of Engineers
US F&I S
Rec. No. District Enaineer 's View and Comments
1 . I do not concur in the US F&WS 's recommendation that the channel
modification proposed under the recommended plans for flood
control be abandoned since the only approaches to alleviating
flood damages in the Mamaroneck and Sheldrake Rivers Basin, N.Y.
found to be economically justified and meriting Federal participa-
tion include channel modification. Expanding the size and extent
of existing floodwalls was evaluated as a flood control measure,
but was found to be economically unjustified for the same degree
of flood protection that would be provided by channel modifica-
tion. It is noted that as a result of coordination with the US
F&WS the recommended plans for flood control are designed to
minimize removal of trees and shrubs, to restrict removal of trees
and shrubs to one streambank where possible, and to replace trees
and shrubs to be removed during channel modification. During
preconstruction planning, coordination will be effected with the
NYSDEC to select equivalent forms and species of trees and shrubs
having high wildlife values for those trees and shrubs to be
replaced.
2. I concur in the US F&[SS's recommendation that silt and turbidity
curtains be used in both rivers and along their banks during
construction to minimize any adverse effect on water quality and
to control soil erosion into the waterways.
3. I concur in the US F&WS's recommendation that all streambanks be
mulched and seeded immediately following construction, section by
section, to alleviate potential erosion.
4. I do not concur in the US F&WS 's recommendation that all natural
streams meanders be maintained in the sections of the rivers where
floodwall (actually retaining wall) construction or channel
modifications are anticipated, since this would be technically
inconsistent with the purpose of providing flood control under the
recommended plans. However, I do concur in the US F&WS 's
recommendation to construct a meandering, low-flow pilot channel
along the more densely vegetated streambank (unless the vegetated
bank is on the inside of a stream, curve) , since this type of a
NANEN-Cy 9 February 1979
SUBJECT: New York District Engineer's Views and Comments on Recommendations by
US F&WS in the Final Fish and Wildlif.� Coordination Act Report dated
13 September 1.978 for the Feasibility Report on the Mamaroneck and
Sheldrake Rivers Basin, New York, Prepared by the New York District,
Corps of Engineers
US F&'WS
Rec. No. District Engineer 's View and Comments
4. mitigation measure is technically compatible with the channel
(Cont 'd) modification works proposed tinder the recommended plans for flood
control.
5. I do not concur in the US F&IdS 's recommendation that the low lying
floodplain areas on the Sheldrake River downstream of Revere Road
to Fenimore Road not be filled in, since their alledgedly high
biological value has not been demonstrated and filling this land
in is considered to be socially and economically desirable and
will minimize costs for interior drainage work required in connec-
tion with the recomr.;cnded plan for flood control. I also do not
concur with the US F&tdS's recommendation to construct the Fayette
Avenue retaininc- wall as far landward as possible since the
existing commercial and residential land-use areas would be
restricted and relocation of the proposed retaining wall would not
avoid any significant impacts to the existing streambank
vegetation.
6. I do not concur in the US F&WS 's recommendation that the Fenimore
Road diversion tunnel inlet be modified to divert onlv that
portion of the flood flow which is in excess of the lower
Sheldrake River's natural bankfull capacity, since the fish and
wildlife resources in this section are considered to be minimal
and local interests have expressed their desires that flood flows
in the Sheldrake River be completely diverted into the proposed
Fenimore Avenue tunnel. Technically, complete diversion is also
considered to increase the reliability and safety in the design of
the proposed Fenimore Avenue tunnel, and will assure the elimina-
tion of flood damages in the area between Fenimore Avenue and
Mamaroneck Avenue which has experienced severe flood damages.
y 7. I do not concur in the US F&WS 's recommendation that tine proposed
filling of low-lying areas within the Hamaroneck River flood plain
be abandoned and instead floodwalls be constructed as far landward
as possible, since such an action is considered to be socially and
economically undesirable and would incroase costs for interior
drainage work required in connection with the recommended clan for
2
NANEN-CY 9 February 1979
SUBJECT: New York District En.gineer 's Views and Comments on Recommendations by
US F&.,'S in the Final Fish and ',wildlife Coordination Act Report dated
13 September 1978 for the Feasibility Report on the Mamaroneck and
Sheldrake Rivers Basin, New York, Prepared by the New York District ,
Corps of Engineers
US FI�Ws
Rec. No. District Enzineer's View and Comments
7. flood control with only minimal preservation of floodplain
(Cont'd) habitat.
S. I concur in the US F&idS 's recommendation that several log and rock
crib dams be constructed in the 'Mamaroneck and Sheldrake Rivers to
mitigate the loss of aquatic and benthic habitat that would be
removed by the proposed channel modification works under the
recommended plans for flood control. Tile specific locations and
design requirements will be worked out during the preconstruction
planning phase. However, it is not considered feasible to leave
both banks undisturbed 30 feet upstream and downstream of each of
the log and crib dams.
9. I do not concur in the US F&WS's recommendation that the proposed
relocation of the confluence of the Sheldrake and Mamaroneck
Rivers within Columbus Park and tine relocation of a parking lot at
this site be abandoned. I agree that the proposed Fenimore Road
diversion tunnel will greatly reduce flood flows from the
Sheldrake River into Columbus Park since it is designed for that
Purpose. Nevertheless , flood flows from the Mamaroneck River into
Columbus Park are substantial enough to require the realignment of
the Mamaroneck River in the vicinity of the confluence with the
Sheldrake River to promote passage of flood flows. Without such a
proposed relocation, flood stages would be significantly increased
upstream of Jefferson Avenue requiring more extensive structural
flood control works for the same level of protection. The
necessary relocation of the confluence of the Mamaroneck and
Sheldrake Rivers results in the elimination of an existing parking
field on the left bank of the Mamaroneck River along Jefferson
Avenue, and in accordance with the desires of local interests a
parking lot is proposed to be developed on fill adjacent to the
right bank of the Sheldrake and Mamaroneck Rivers at their
confluence in Columbus Park.
3
! � DEPARTMENT OF THE ARMY
NEW YORK DISTRICT. CORPS OF ENGINEERS
26 FEDERAL PLAZA
" NEW YORK. N. Y. 10007
�y REPLY TO
�•r AT TEN TIOM OF:
NANEN-Cy 9 FEB 1919
Mr. Paul P. Hamilton
Field Supervisor, Cortland, N.Y. Field Station
U.S. Fish and Wildlife Service, USDI
100 Grange Place, Room 202
Cortland, New York 13045
Dear Mr. Hamilton:
This is in reply to the final Fish and Wildlife Coordination Act (F&'-.CA)
report dated 16 October 1978 and prepared by your office on the impacts
the flood control improvements prQDosed by the New York District , Corps of
Engineers for the Byram River at Port Chester, New York and Byram,
Connecticut will have on fish and wildlife resources.
I have reviewed your final F&WCA report and the eleven (11 ) recommendations
contained therein to mitigate the adverse impacts to the existing fish and
wildlife resources in the area that would be affected by flood control
improvements proposed by the New York District , Corps of Engineers. In
accordance with the desires expressed in the last paragraph of the final
F&WCA report, all of the US F&WS ' s recommendations will be considered
during preconstruction planning which would be the next phase of planning
subsequent to authorization of a Federal flood control project by the
Congress. However, my views and comments on the recommendations in the
final F&WCA report are inclosed herewith for your information, since the
final F&WCA report along with my views and comments will be attached to
the final EIS for the Byram River Basin, New York and Connecticut , and
incorporated as one of its ancillary documents which will be presented to
the Congress as a package.
Your assistance on this matter is appreciated, and I look forward to your
timely cooperation on this matter in the future.
Sincerely yours,
1 Incl CLARK H. BENN
As Stated Colonel , Corps of En,,ineers
District Engineer
NANEN-Cy 9 February 1979
SUBJECT: New York District Engineer's Views and Comments on Recommendations by
US F&WS in the Final Fish and wildlife Coordination Act Report dated
16 October 1973 for the Feasibility Report on the Byram River Basin,
New York and Connecticut, Prepared by the New York District , Corps of
Engineers
US F&',dS
Rec. No. District Engineer's View and Comments
1 . I concur with the US F&WS's recommendation to minimize the removal
of trees and shrubs.
2. I concur with the US F&WS's recommendation to restrict removal of
trees and shrubs to the one stream bank that has the least amount
of vegetation in any particular reach of the river, and where that
is physically possible while still providing flood protection.
3. I concur with the US F&WS 's recommendation that trees and shrubs
removed during construction of the proposed flood control improve-
ments be replaced. During preconstruction planning, coordination
will be effected with the NYSDEC and Conn. DEC to select trees and
shrubs having high wildlife values for those trees and shrubs to
be replaced.
4. I concur with the US F&WS's recommendation that streambanks should
be seeded and mulched immediately following construction, section
by section, to alleviate potential erosion.
5. I concur with the US F&WS 's recommendation that silt and turbidity
curtains be used in the river to control silts from leaching into
the waterway.
6. I do not concur in the US F&WS's recommendation that all natural
stream meanders be maintained in the sections of the river where
channel modifications are anticipated, since this would be
physically inconsistent with providing flood control under the
recommended plan.
7. I concur in the US F&WS 's recommendations to construct a low-flow
pilot channel along the more densely vegetated river bank, since
this type of mitigation measure is physically compatible with the
channel modification, levee and floodwall improvements proposed
under the recommended plan for flood control.
NANEN-Cy 9 February 1979
SUBJECT: New York District Engineer's Views and Comments on Recommendations by
US F&WS in the Final "ish and ;dildlife Coordination Act Report dated
16 October 1978 for the Feasibility Report on the Byram River Basin,
New York and Connecticut, Prepared by the New York District, Corps of
Engineers
US F&kS
Rec. No. District En-ineer's View and Comments
8. I concur in the US F&WS's recommendation to construct a series of
artificial pools within the modified river channel. The specific
locations and design requirements will be worked out during the
preconstruction planning phase.
9. I concur in the US F&WS's recommendation to place boulders or
rocks in wire baskets on the bottoms of the artificial pools to
create and diversify aquatic habitat.
10. I concur in the US F&WS's recommendation to minimize disturbing
streamside vegetation 30 feet upstream and downstream of the
artificial pools. However, it is not considered feasible to leave
the streambank vegetation on both banks undisturbed.
11. I concur in the US F&WS's recommendation that the proposed
construction in the floodplain should be consistent with President
Carter's Executive Order No. 11988 published in the Federal
Register dated 25 May 1977 regarding floodplain management.
2
F-1 CORPS OF ENGINEERS U.S. ARMY
I / �
XEN SILO
4L RESERVOIR
WESTCHESTER,
COUNTY Wk �
AIRPORT
\0
Q:
lTE 0
ILA,
'T
0
0
k
4
I
"IT
4
10
HART.S.JALE
MAPLE
MOOR
IV 0",
o 41
SCARSOALE STA. Oi 4.
101.A&
4L
LAGE
0
4
WrSrCNiSrror jow .5
c1l, WATER WORKS lu
AC RESERVOIR
�llr BRAS
ri
-0
0
0
Nu
C.11IT-00.1. U04
VILL AGE OF Z
LAIRCH&CAIr 'MAIC" Jb
RESERVOIRS
NO, .2
)I- SHIFLORAKE -9
LAKE
...... AD
__-MAMAROAf_Cl(
NARAM
p +
0
LARCNAIONT lARONrORTI
GALDENS ITA
DENS
LAI(f sout4o
PIN
�
LEGEND
BASIN PERIMETER
PP!MARY ROAD 0
SECONDARY ROAD
STREAM
MAMARONECK AND SHELDRAKE RIVERS
0 1
I BASIN MAP
SCALE IN MILES
VILLAGE AND TOWN OF MAMARONECK
FWURE
TOWN OF SCAFtIMLE
n
TOWN OF _ ECKSCARSDALE
YAMARON
VILLAGE OF LARCNYONTC- �
RFSERYONP AQY �_iE.
/ 99Y/JJ__Iccc'V /
�
VILLAGE a' LARcAiv YT r
RESERVOIR NO./
r � �
TOWN OF
MAMARONECK
STUDY AREA
1 `
/ � i �❑� 1 °p' I J 1
CITY OF / 11� ��� I r /t / I I Ao dFry/'aoN LJ I �oOO I Z
NEW ROCMELLE / v" �\` " ESS 1 N 0'
Y O O 1
DOD
O� I
p
TOWN OF p
c/c�` � MAMARONECK 1 '� I / � EKE � r�� O a cp
GARLET :. `-- ��� � ��� " ❑Dai ��`\�1p 1
/ L
R.R. I
r-ss NEW YORK STATE THRUWAY N.N.R R. NALSTEA0 I VILLAGE' OF
OWN of YAYARONECK - L— L� 1 a�. ^��
I J < L ' I' ' MAMARONECK
L_J LLAGE F LARCYMONT S�UDY AREA
1 � N.N.R.R. > NUE'
�!U✓ 1PALMERAVENUE I ppLYEp 'lI)fes/ W ��u
n P L I AVENUEo��J V P W nnnn 1
A~ 3C` ,C �� VILLAGE \ 1
=10 - ! D�C� < OF
MAMARONECK> I
VILLAGE OF j
LARCHMONT Z $ o
3? I60STON POST aoao f
/ tiO £ ` uUS-I � a
; J V r
BOgr l WEST a 0�
\ ���A ` t BAS/N �'
J,
EAST BASINiEK�
�,/ J��v PARK,MA'1 / Ad
-PINE oA 0
SCALE YI FEET
�>,� ��W E ,� , � �,, � O ✓ (� ��}' soo o soo rsao
TTER CREEK 40'
I/l
� l
.o MAMARONECK AND SHELDRAKE RIVERS
` wL LOCATION MAPPRECOVE
ONNG
r ! LARCNNONT HARBOR -
;;' / C _!— ,� �2� v AN�G£.�L� VILLAGE AND TOWN
1�✓ S ' J��\
LONG /SL AND / SOUND ,,� /�\ `\\ I� LONG ISLAND SOUND (' i OF r
MAMARONECK,N.Y.
FXWE 2
I
LEGEND
-� RETAINING WALL
—T-TT CUT SLOPE \ ` • \`� 4'2
CHANNEL BOTTOM
TIT CUT SLOPE ' A 3 v
WESTCNESTER, \
FILLED AREA ✓O/NT WATER f�•':
LIMIT OF WC
WORKS DAM
ir--T--i-r� LEVEE ' THE NACK w"
MlDK TO S
I/ IEYOVED.By OFtlGf I
SCALE IN FEET ,� �4c ?� ,h• v �.
300 0 300 SOO
ONEcK
AM i GEONEY 1 S
POND - _ ! _�' `..KORO r'Y(/r" Mh 'l
MI
Of NKK i iR � / N q�
�O^ OF MPMat/AR/ To
NEW ry
7 ScR4yFq i. fYG GF TD J,y�
M rD
�E sr4T w <Yt�
_ fes" vg4N 4�f .l ~ y
\` q
E Tr,RUW P`
'SEW YORK. -ST
SET STRUCTURE
PROPOSED
r a
A0ap0
'A STREET . 'Z w _
P PV NJE ,'.•p X44.�,ir' 4i 4•
FAYFT/E AVE LIE 10 nLUAKD h - �E PC DO►00 _ p ? ,Q c `QW
j �" 1'�rt MAMT4NED rOK 'CP
`S m 0
\\ OD , a CENTER AVE LOCAL DRAINAGE P` Fy AO
UPSTREAM USER OF WORK EAT IKLLI
µPN- ♦S' NNE AVENUE MIRK Z
- $ ,y F
• ���?p - PROPOSED IfLEYEE Z WAVFRLY AVENUE Ay VPN RGgVE � •+ N i
PO FOOT MIow ' ¢ j W G S
O
o SNELD_RAKE R;PER 1 I rRp�rO�Fp. AVE 3 .n 4 a u w -- -- O
iIo;GDLOT
DREW
(y Cr O. NEW HAVEN RAILROAD i - STAT-ON
EX MIOSEZA _AT PLAZA MORE 4 NEW HAVEN RAILRC40 y�l'
t 1 T 1 1. E-1-=-ri_ i.I 1 i i 1 1 l=: ! 't I . 1 l 1-}-4 t-` -1 1 i -1 1-1=4�! 1� f-- ! i ! _ : ! �t i ` i#k i 6�� ='-�7 fr�f x-4-4 4 id---I I J•1 1 }"1.-.i_-I-k=awl :-!a Ao D
O ? TQ+00 1 ^
�P o4 STANLEY '� �' \�AVEOPOSED NEW s�M HALSTE AD INA Z
arP �Q i AVENUE ..VAl4EY. LG!•re r --. C; N
QO \ �' ,, .' 'pL.. . PROPOSED INVERTED SIPHON TO "T`
O
W REPLACE EOSTSM SEWER MIDIIE Z
PALMER i - AVENUE i Q - _I =4VEf1UE
> op
32 coi" j _
PROPOSED NEW WAD STREET MIDSE W -
- _ e
!-*410
v
i I _ _Ki.Do Toy \
DME
1
BOSTON DOST ROAD I N f / CHANNELCNANL
N
REMN -
4
�...' R
�'•�\ �� _ RI DOWNSTREAM LT OF WO .aPfF.
\`'�- --- - J• ! ' WESr BASOiNT MlMMTODRENERS7 -- V``�\ !, STREAMS IN WESTCHESTER COUNTY,N.Y.
MAMAF^NECK
----
NARB(R �, �osr AND FAIRFIELD COUNTY, CONN.
- ---, � ,(( � ,� - MAMARONECK AND SHELORAKE RIVERS BASIN,N.Y.
EAST BAS,N VILLAGE OF MAMARONECK GENERAL PLAN'� ✓ �.. �. I
MAMARONECK / / - � =" L Ievr OF THE ARMY
. .DEPORTMEM
oKCORPS OF ONw[Oa
HARBOR YDlllt,NO Y¢IR
KfnMo' R[eaRRRRrO[o•
— a....u....�.....�.�...D.Y.D��N....o.
ANNOYED• o—A Dow"MANOR
onan.c.i'. r t�iEE OrfINO RH
FIGURE 3
TIE WTO amn4vaL
e0
ET
LEGEND wEAVEN _ aEEt1110
t. ` 1rT .fel S�. �., --
w
RETAKING WALL -�' p� [ ~_ M7p�O�Ep�
PROPOSED CONCRETE FLUME 'Arn.Oplu Eif ;Q
Y CUT SLOPE lv Q r9' .•-`� i . `\` �
CHANNEL BOTTOM �` 9 �.
CUT SLOPE _ �•. 1'
�OC OO SO,�
FILLED AREA .. y 1 ..\ - y ,p�
®
BUILDINGS TO BE REMOVED
SMEI ORAN
� �, 4 L� F AVFNUF: � r ^,l G ill a �J�•'-ti*2•
'O y 1 yl �y �gg' • \ ` \
•.� , �
i
FnolI�rE . sraNE r� _
I.
'OEm
` Z
SCALE N FEET
100 0 100 200 S00 ,
if,. v
-4NSDOWNE CR1VE 1
'aLE EY c
wp1 V y`
f .� - �•�
D
oo. m z E
! so r
eao'oµ
Ppr o
! J
X
a
r
STREAMS IN WESTCHESTER COUNTY,N.Y.
AND FAIRFIELD COUNTY, CONN.
MAMARONECK AND SHELDRAKE RIVERS BASIN.NY
TOWN OF MAMARONIC GENERAL PLAN;
DEPARTMENT OF TME ARMY
NEW—D15—T,CORPS D<F—EEM
REw,ORF,%Ew 10Rk
11I111TTED REVIEWED. 11ECDM11E11EED,
ADPROIED MueR� OM'M RM�R
—1 c t.—T cw•RaR eMA99 by
FIGURE 4
c ' D
41t-"N,
` O N K C O N N.
0 I
-/ \ e / lE / IREr
IIAv
et, PEEKSKILL
I u
/ R•R.Y RIVER
,DR IN.G[ RE• RRIOOC T
A. $ OR [RM1CR` G 1 S 1.A M O
AV
SCASISCIAL
c 1 L A
I-• / J W S
IIEVARR ° PL G
Z)
f LIMITS OF ; r
SASIN STUDIE / 1 C
IEEE FI6.21 W \' T c A N t
LO',ATIO14 MAP
SCALE Of Y!L[1
I
S.'.IL
\ ARMONK i r
! 107
0 ,/ ROUND HILL
q MfRLR/
61
0
b
Jf • NI RIVERSVILLE
I
ti
f'
1
GLL
ENVILLE
0
b ,PEMBERWICK
:, o
Z -c
LEGEND \ A'
10 MIL[s FROM MOUTH OF SYRAM RIVER
EXISTING DAM
R SRIOGIE 1
PORT CHESTER
1
1
BYRAM RIVER
CALF ISLANDS
FLOOD CONTROL PROJECT
/ 1 0 aTRAM PT. k°
PLAN 0
SEALE OF MILES RYE ON4 SO
SJ .
o I ,\ —f l OREENNIICH PORTCHESTER
1 CONNECTICUT NEW YORK
FIGURE 5
INLET
AIA SII AVEN
rI.[
-EXIST.24*
DRAIN M
ASAM)OMFDAji
C3
IRL-A,
GE
"ItRIDALE
7gxsI
i-l
Lol Ac
EVer w-
st*-
FA FILL Tr
C foRy, E
FL ov., Cge
L------------------
ILl
(1-R-I TIE-BACK WALL
RFLIEF D"
OD
6-- ROEPLAIS -RLPLAtL
4f 0?/VE R
s,- A 'T EXIS'ING Y'S
I P GAS LINE
_p
NI CW 449 j '"A"I FRp SNEW A D PROPOSED A D GATE
7 AT
7
rLDGD WALL tX(A_W AND 30*0 EXTENSION 0
SI GATE OF EXISTING DRAIN
Aft GATE
0
50
t-40
-uposto
PPOIOSEO
-,,,F 30o '
J DRAIN
w
TIEBACK
PROI z
A D7 --T
D.IATI, PRO ST RELIEF MH
WITH
A
SED 18'0 SLI.1111 GAT REU)CATION-1 I AND SLUICE
A zDDITCNJ ED r
LUKIE ANARKING REPSTOU
A.b GATE G- p NEW REL;EF --ILEVEES PROPOSED 2:4'
ELIEF DRAIN Di rCH AND INLET--J AND
(iz i =
MH WA14D r
'Z, POND ELEV SLUICE GATE A 0 GATE j L
PRDP-S -1W 11 'IF
I 1JWIT" A 1)
GATE,SLUICE
JO' PROPOSED 'EW -CI [ .D. :
PUMP STA E:41 T'I_ 48 -,
GATE,AND INLET
POSED E
EXIST I PROACCESS HOMESTEAD Ll
TO REMAIN--IROAD
icil j
ANE
f E
jr- j D
LiLi !-I r
j 4`5
El 0
C7
i T
O-E
j
C3
rr" EQ
CAROLINA PLACE
PROppgE0 24 RELIEF
DRAIN WITMA D GATE
AND SLUICE GAT
S
70 75+00
8 PRAM `
W PROPOSED LEVEE Rlv c /-UPTREAM LIMIT OF WORK
PROPOSED we PROPOSED PROPOSED LEVEE To
0 A 0 GATE A 0 GATE_: MEET EXISTING LEVEE
DRAINAGE O LEGEND
DITCH
:=ED PRMSED L- STRUCTURE TO BE REMOVED
MH :R E,LIEUF,C M.N
AND - E.H
REL 3 41 13
PROPOSE SLUICED GOATID l PROPOSED PUMP STATION
24.0 REMAIN
42bd
IN TO
Sy
DRAIN7—'j;'tt-EXI$TRIG 27.0 W' REMAIN7 4.
P DRA FILL
EXISTING DRAIN
(I ET c
_ET
IN
SLUICEyVft
ROSS --T RE
PROPOSED DRAIN w 0 KID ml 1.
E i ,/ --
k PROPOSED DRAINAGE DITCH SCALE IN FEET
------0— PROPOSED MH OR INLET//+VIII... 1 lu/ // o
p
BYRAM RIVER
7/ AU
foiilcK CONSIDERED PLAN
-f!f ,I D Q -- —19,90
Ex-
7 GREENWICH, CONNECTICUT
EXISTING gNEA PORT CHESTER, NEW YORK
P FOX STREET DRAINAGE
DITCH
FIGURE 6