HomeMy WebLinkAbout2007_7_11_Local_Law_No_8 Local Law No. 8 —2007
This local law shall be known as the "Flood Damage Prevention" Law.
BE IT ENACTED by the Town Board of the Town of Mamaroneck
Section 1 —Purpose:
New Flood Insurance Rate Maps establishing 100-year base flood elevations for the Town of
Mamaroneck recently have been completed by the Federal Emergency Management Agency. For
property in the Town of Mamaroneck to remain eligible for the National Flood Insurance Program, the
Town's existing Flood Damage Prevention Law must be updated to meet the standards of the National
Flood Insurance Program. This local law does just that.
Section 2—Amendment of a current section of the Mamaroneck Code:
Chapter 110 of the Code of the Town of Mamaroneck hereby is repealed and the following substituted
in its place:
Chapter 110
FLOOD DAMAGE PROTECTION
§ 110-1 Findings
§ 110-2 Statement of Purpose
§110-3 Objectives
§ 110-4 Definitions
§ 110-5 Applicability
§ 110-6 Basis for Establishing the Areas of Special Flood Hazard
§ 110-7 Interpretation and Conflict with Other Laws
§ 110-8 Severability
§ 110-9 Penalties for Non-Compliance
§ 110-10 Warning and Disclaimer of Liability
§ 110-11 Designation of Local Administrator
§ 110-12 Floodplain Development Permit
§ 110-13 Duties and Responsibilities of the Local Administrator
§ 110-14 General Construction Standards
§ 110-15 Coastal High Hazard Areas
§ 110-16 Subdivision Proposals
§ 110-17 Encroachments
§ 110-18 Standards for All Structures
§ 110-19 Standards for Residential Structures Outside Coastal High Hazard Areas
§ 110-20 Standards for Residential Structures Within Coastal High Hazard Areas
§ 110-21 Standards for Non-Residential Structures Outside Coastal High Hazard Areas
§ 110-22 Standards for Non-Residential Structures Within Coastal High Hazard Areas
§ 110-23 Critical Facilities
§ 110-24 Manufactured Homes and Recreational Vehicles
§ 110-25 Appeals Board
§ 110-26 Conditions for Variances
§ 110-1 Findings.
The Town Board of the Town of Mamaroneck finds that the potential and/or actual damages from
flooding and erosion may be a problem to the residents of the Town of Mamaroneck and that such
damages may include: destruction or loss of private and public housing, damage to public
facilities, both publicly and privately owned, and injury to and loss of human life. In order to
minimize the threat of such damages and to achieve the purposes and objectives hereinafter set
forth, this chapter is adopted.
§ 110-2 Statement of Purpose.
It is the purpose of this chapter to promote the public health, safety, and general welfare, and to
minimize public and private losses due to flood conditions in specific areas by provisions designed
to:
(1) regulate uses which are dangerous to health, safety and property due to water or erosion
hazards, or which result in damaging increases in erosion or in flood heights or velocities;
(2) require that uses vulnerable to floods, including facilities which serve such uses, be
protected against flood damage at the time of initial construction;
2
(3) control the alteration of natural floodplains, stream channels, and natural protective barriers
which are involved in the accommodation of flood waters;
(4) control filling, grading, dredging and other development which may increase erosion or
flood damages;
(5) regulate the construction of flood barriers which will unnaturally divert flood waters or
which may increase flood hazards to other lands, and;
(6) qualify and maintain for participation in the National Flood Insurance Program.
§ 110-3 Objectives.
The objectives of this chapter are:
(1) to protect human life and health;
(2) to minimize expenditure of public money for costly flood control projects;
(3) to minimize the need for rescue and relief efforts associated with flooding and generally
undertaken at the expense of the general public;
(4) to minimize prolonged business interruptions;
(5) to minimize damage to public facilities and utilities such as water and gas mains, electric,
telephone, sewer lines, streets and bridges located in areas of special flood hazard;
(6) to help maintain a stable tax base by providing for the sound use and development of areas
of special flood hazard so as to minimize future flood blight areas;
(7) to provide that developers are notified that property is in an area of special flood hazard;
and,
(8) to ensure that those who occupy the areas of special flood hazard assume responsibility for
their actions.
§ 110-4 Definitions.
A. Unless specifically defined below, words or phrases used in this chapter shall be interpreted so as
to give them the meaning they have in common usage and to give this chapter its most
reasonable application.
B. As used in this chapter, the following terms shall have the meaning indicated.
APPEALS - A request for a review of the Local Administrator's interpretation of any provision of this
Chapter or a request for a variance.
3
AREA OF SHALLOW FLOODING - A designated AO, AH or VO Zone on a community's Flood
Insurance Rate Map (FIRM) with a one percent or greater annual chance of flooding to an average
annual depth of one to three feet where a clearly defined channel does not exist, where the path of
flooding is unpredictable and where velocity flow may be evident. Such flooding is characterized by
ponding or sheet flow.
AREA OF SPECIAL FLOODING HAZARD - The land in the floodplain within a community subject
to a one percent or greater chance of flooding in any given year. This area may be designated as Zone A,
AE, AH, AO, Al-A30, A99, V, VO, VE, or V1-V30. It is also commonly referred to as the base flood-
plain or 100-year floodplain. For purposes of this chapter, the term SPECIAL FLOOD HAZARD
AREA (SFHA) is synonymous in meaning with the phrase AREA OF SPECIAL FLOOD HAZARD.
BASE FLOOD - The flood having a one percent chance of being equaled or exceeded in any given year.
BASEMENT - That portion of a building having its floor sub grade (below ground level) on all sides.
BREAKAWAY WALL - A wall that is not part of the structural support of the building and is intended
through its design and construction to collapse under specific lateral loading forces without causing
damage to the elevated portion of the building or the supporting foundation system.
BUILDING - see STRUCTURE.
CELLAR - has the same meaning as BASEMENT.
COASTAL HIGH HAZARD AREA - An area of special flood hazard extending from offshore to the
inland limit of a primary frontal dune along an open coast and any other area subject to high velocity
wave action from storms or seismic sources. The area is designated on a FIRM as Zone Vl-V30, VE,
VO or V.
CRAWL SPACE - An enclosed area beneath the lowest elevated floor, eighteen inches or more in
height, which is used to service the underside of the lowest elevated floor. The elevation of the floor of
this enclosed area, which may be of soil, gravel, concrete or other material, must be equal to or above
the lowest adjacent exterior grade. The enclosed crawl space area shall be properly vented to allow for
the equalization of hydrostatic forces which would be experienced during periods of flooding.
CRITICAL FACILITIES —Any of the following:
(1) Structures or facilities that produce, use, or store highly volatile, flammable, explosive,
toxic and/or water-reactive materials;
(2) Hospitals, nursing homes, and housing likely to contain occupants who may not be
sufficiently mobile to avoid death or injury during a flood;
(3) Police stations, fire stations, vehicle and equipment storage facilities, and emergency
operations centers that are needed for flood response activities before, during and after a
flood; or
(4) Public and private facilities that are vital to maintaining or restoring normal services to
flooded areas before, during and after a flood.
CUMULATIVE SUBSTANTIAL IMPROVEMENT—Any reconstruction, rehabilitation, addition, or
other improvement of a structure that equals or exceeds 50 percent of the market value of the structure at
the time of the improvement or repair when counted cumulatively for 10 years.
4
DEVELOPMENT - Any man-made change to improved or unimproved real estate, including but not
limited to buildings or other structures, mining, dredging, filling, paving, excavation or drilling
operations or storage of equipment or materials.
ELEVATED BUILDING - A non-basement building (i) built, in the case of a building in Zones A1-
A30, AE, A, A99, AO, AH, B, C, X, or D, to have the top of the elevated floor, or in the case of a
building in Zones V1-30, VE, or V, to have the bottom of the lowest horizontal structure member of the
elevated floor, elevated above the ground level by means of pilings, columns (posts and piers), or shear
walls parallel to the flow of the water and (ii) adequately anchored so as not to impair the structural
integrity of the building during a flood of up to the magnitude of the base flood. In the case of Zones
Al-A30, AE, A, A99, AO, AH, B, C, X, or D, ELEVATED BUILDING also includes a building
elevated by means of fill or solid foundation perimeter walls with openings sufficient to facilitate the
unimpeded movement of flood waters. In the case of Zones V1-V30, VE, or V, ELEVATED
BUILDING also includes a building otherwise meeting the definition of ELEVATED BUILDING, even
though the lower area is enclosed by means of breakaway walls that meet the federal standards.
FEDERAL EMERGENCY MANAGEMENT AGENCY - The Federal agency that administers the
National Flood Insurance Program.
FLOOD OR FLOODING - A general and temporary condition of partial or complete inundation of
normally dry land areas from:
(1) the overflow of inland or tidal waters;
(2) the unusual and rapid accumulation or runoff of surface waters from any source.
FLOOD or FLOODING also means the collapse or subsidence of land along the shore of a lake or other
body of water as a result of erosion or undermining caused by waves or currents of water exceeding
anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of
water, accompanied by a severe storm, or by an unanticipated force of nature, such as a flash flood or an
abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as
defined in (1) above.
FLOOD BOUNDARY AND FLOODWAY MAP (FBFM) - An official map of the community
published by the Federal Emergency Management Agency as part of a riverine community's Flood
Insurance Study. The FBFM delineates a Regulatory Floodway along water courses studied in detail in
the Flood Insurance Study.
FLOOD ELEVATION STUDY - An examination, evaluation and determination of the flood hazards
and, if appropriate, corresponding water surface elevations, or an examination, evaluation and
determination of flood- related erosion hazards.
FLOOD HAZARD BOUNDARY MAP (FHBM) - An official map of a community, issued by the
Federal Emergency Management Agency, where the boundaries of the areas of special flood hazard
have been designated as Zone A but no flood elevations are provided.
FLOOD INSURANCE RATE MAP (FIRM) - An official map of a community, on which the Federal
Emergency Management Agency has delineated both the areas of special flood hazard and the risk
premium zones applicable to the community.
5
FLOOD INSURANCE STUDY - see FLOOD ELEVATION STUDY.
FLOODPLAIN OR FLOOD-PRONE AREA - Any land area susceptible to being inundated by water
from any source (see definition of FLOODING).
FLOODPROOFING - Any combination of structural and non-structural additions, changes, or
adjustments to structures which reduce or eliminate flood damage to real estate or improved real
property, water and sanitary facilities, structures and their contents.
FLOODWAY - has the same meaning as REGULATORY FLOODWAY.
FUNCTIONALLY DEPENDENT USE- A use which cannot perform its intended purpose unless it is
located or carried out in close proximity to water, such as a docking or port facility necessary for the
loading and unloading of cargo or passengers, shipbuilding, and ship repair facilities. The term does not
include long-term storage, manufacturing, sales, or service facilities.
HIGHEST ADJACENT GRADE - The highest natural elevation of the ground surface, prior to
construction, next to the proposed walls of a structure.
HISTORIC STRUCTURE - Any structure that is:
(1) listed individually in the National Register of Historic Places (a listing maintained by the
Department of the Interior) or preliminarily determined by the Secretary of the Interior as
meeting the requirements for individual listing on the National Register;
(2) certified or preliminarily determined by the Secretary of the Interior as contributing to the
historical significance of a registered historic district or a district preliminarily determined
by the Secretary to qualify as a registered historic district;
(3) individually listed on a state inventory of historic places in states with historic preservation
programs which have been approved by the Secretary of the Interior; or
(4) individually listed on a local inventory of historic places in communities with historic
preservation programs that have been certified either:
(i) by an approved state program as determined by the Secretary of the Interior or
(ii) directly by the Secretary of the Interior in states without approved programs.
LOCAL ADMINISTRATOR - The person appointed by the community to administer and implement
this chapter by granting or denying development permits in accordance with its provisions. This person
is often the Building Inspector, Code Enforcement Officer, or employee of an engineering department.
LOWEST FLOOR - Lowest floor of the lowest enclosed area(including basement or cellar). An
unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access, or storage
in an area other than a basement area is not considered a building's lowest floor;provided, that such
enclosure is not built so as to render the structure in violation of the applicable non-elevation design
requirements of this Chapter.
6
MANUFACTURED HOME - A structure, transportable in one or more sections, which is built on a
permanent chassis and designed to be used with or without a permanent foundation when connected to
the required utilities. The term does not include a RECREATIONAL VEHICLE.
MANUFACTURED HOME PARK OR SUBDIVISION - A parcel(or contiguous parcels) of land
divided into two or more manufactured home lots for rent or sale.
MEAN SEA LEVEL - For purposes of the National Flood Insurance Program, the National Geodetic
Vertical Datum (NGVD) of 1929, the North American Vertical Datum of 1988 (NAVD 88), or other
datum to which base flood elevations shown on a community's Flood Insurance Rate Map are
referenced.
MOBILE HOME - has the same meaning as MANUFACTURED HOME.
NEW CONSTRUCTION - Structures for which the START OF CONSTRUCTION commenced on or
after the effective date of a floodplain management regulation adopted by the community and includes
any subsequent improvements to such structure.
ONE HUNDRED YEAR FLOOD or 100-YEAR FLOOD - has the same meaning as BASE FLOOD.
PRIMARY FRONTAL DUNE - A continuous or nearly continuous mound or ridge of sand with
relatively steep seaward and landward slopes immediately landward and adjacent to the beach and
subject to erosion and overtopping from high tides and waves during major coastal storms. The inland
limit of the primary frontal dune occurs at the point where there is a distinct change from a relatively
steep slope to a relatively mild slope.
PRINCIPALLY ABOVE GROUND —A structure with at least 51 percent of its actual cash value,
excluding land value, above ground.
RECREATIONAL VEHICLE - A vehicle which is:
(1) built on a single chassis;
(2) 400 square feet or less when measured at the largest horizontal projections;
(3) designed to be self-propelled or permanently tow able by a light duty truck; and
(4) not designed primarily for use as a permanent dwelling but as temporary living quarters
for recreational, camping, travel, or seasonal use.
REGULATORY FLOODWAY - The channel of a river or other watercourse and the adjacent land areas
that must be reserved in order to discharge the base flood without cumulatively increasing the water
surface elevation more than a designated height as determined by the Federal Emergency Management
Agency in a Flood Insurance Study or by other agencies as provided in Section 110-13 B. of this Law.
SAND DUNES - Naturally occurring accumulations of sand in ridges or mounds landward of the beach.
7
START OF CONSTRUCTION - The date of permit issuance for new construction and substantial
improvements to existing structures, provided that actual start of construction, repair, reconstruction,
rehabilitation, addition placement, or other improvement is within 180 days after the date of issuance.
The actual start of construction means the first placement of permanent construction of a building
(including a manufactured home) on a site, such as the pouring of a slab or footings, installation of
pilings or construction of columns.
Permanent construction does not include land preparation (such as clearing, excavation, grading, or
filling), or the installation of streets or walkways, or excavation for a basement, footings, piers or
foundations, or the erection of temporary forms, or the installation of accessory buildings such as
garages or sheds not occupied as dwelling units or not part of the main building. For a substantial
improvement, the actual "start of construction" means the first alteration of any wall, ceiling, floor, or
other structural part of a building, whether or not that alteration affects the external dimensions of the
building.
STRUCTURE - A walled and roofed building, including a gas or liquid storage tank, that is principally
above ground, as well as a manufactured home.
SUBSTANTIAL DAMAGE - Damage of any origin sustained by a structure whereby the cost of
restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market
value of the structure before the damage occurred. Substantial damage also means flood-related damages
sustained by a structure on two separate occasions during a 10-year period for which the cost of repairs
at the time of such flood event, on the average, equals or exceeds 25 percent of the market value of the
structure before the damage occurred.
SUBSTANTIAL IMPROVEMENT - Any reconstruction, rehabilitation, addition, or other improvement
of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before
the START OF CONSTRUCTION of the improvement. SUBSTANTIAL IMPROVEMENT also
means CUMULATIVE SUBSTANTIAL IMPROVEMENT. The term includes STRUCTURES which
have incurred SUBSTANTIAL DAMAGE, regardless of the actual repair work performed. The term
does not include, however, either:
(1) any project for improvement of a structure to correct existing violations of state or local
health, sanitary, or safety code specifications which have been identified by the local code
enforcement official and which are the minimum necessary to assure safe living conditions;
or
(2) any alteration of a HISTORIC STRUCTURE,provided that the alteration will not preclude
the structure's continued designation as a HISTORIC STRUCTURE.
VARIANCE - A grant of relief from the requirements of this chapter which permits construction or use
in a manner that would otherwise be prohibited by this chapter.
§ 110-5 Applicability.
This chapter shall apply to all areas of special flood hazard within the unincorporated area of the Town
of Mamaroneck, Westchester County.
8
§ 110-6 Basis for Establishing the Areas of Special Flood Hazard.
The areas of special flood hazard for the Town of Mamaroneck, Community Number 360917, are
identified and defined on the following documents prepared by the Federal Emergency Management
Agency:
(1) Flood Insurance Rate Map Panel Numbers
36119C0332F,36119C0334F,36119C0342F,36119C0351F,
36119C0353F,36119C0361F, whose effective date will be September 28, 2007, and
any subsequent revisions to these map panels that do not affect areas under our
community's jurisdiction.
(2) A scientific and engineering report entitled "Flood Insurance Study, Westchester County, New
York, All Jurisdictions"whose effective date will be September 28, 2007.
The above documents are hereby adopted and declared to be a part of this Chapter. The Flood Insurance
Study and/or maps are on file at the Building Department of the Town of Mamaroneck, Town Center,
740 West Boston Post Road, Mamaroneck, New York 10543.
§ 110-7 Interpretation and Conflict with Other Laws.
This Chapter includes all revisions to the National Flood Insurance Program through March 20, 1997
and shall supersede all previous laws adopted for the purpose of flood damage prevention.
In their interpretation and application, the provisions of this chapter shall be held to be minimum
requirements, adopted for the promotion of the public health, safety, and welfare. Whenever the
requirements of this chapter are at variance with the requirements of any other lawfully adopted rules,
regulations, ordinances, or local laws, the most restrictive, or that imposing the higher standards, shall
govern.
§ 110-8 Severability.
The invalidity of any section or provision of this chapter shall not invalidate any other section or
provision thereof.
§ 110-9 Penalties for Non-Compliance.
No structure in an area of special flood hazard shall hereafter be constructed, located, extended,
converted, or altered and no land shall be excavated or filled without full compliance with the terms of
this chapter and any other applicable regulations. Any infraction of the provisions of this chapter by
failure to comply with any of its requirements, including infractions of conditions and safeguards
established in connection with conditions of the permit, shall constitute a violation. Any person who
violates this chapter or fails to comply with any of its requirements shall, upon conviction thereof, be
fined no more than $250 or imprisoned for not more than 15 days or both. Each day of noncompliance
shall be considered a separate offense. Nothing herein contained shall prevent the Town of
Mamaroneck from taking such other lawful action as necessary to prevent or remedy an infraction. Any
structure found not compliant with the requirements of this chapter for which the developer and/or
9
owner has not applied for and received an approved variance under Sectionl 10-25 will be declared non-
compliant and notification sent to the Federal Emergency Management Agency.
§ 110-10 Warning and Disclaimer of Liability.
The degree of flood protection required by this chapter is considered reasonable for regulatory purposes
and is based on scientific and engineering considerations. Larger floods can and will occur on rare
occasions. Flood heights may be increased by man-made or natural causes. This chapter does not imply
that land outside the area of special flood hazards or uses permitted within such areas will be free from
flooding or flood damages. This chapter shall not create liability on the part of the Town of
Mamaroneck, any officer or employee thereof, or the Federal Emergency Management Agency, for any
flood damages that result from reliance on this chapter or any administrative decision lawfully made
thereunder.
§ 110-11 Designation of the Local Administrator.
The Director of Building Code Enforcement and Land Use Administration is hereby appointed Local
Administrator to administer and implement this chapter by granting or denying floodplain development
permits in accordance with its provisions.
§ 110-12 Floodplain Development Permit.
A. PURPOSE
A floodplain development permit is hereby established for all construction and other
development to be undertaken in areas of special flood hazard in this community for the
purpose of protecting its citizens from increased flood hazards and insuring that new
development is constructed in a manner that minimizes its exposure to flooding. It shall be
unlawful to undertake any development in an area of special flood hazard, as shown on the
Flood Insurance Rate Map enumerated in Section 110-6, without a valid floodplain
development permit. Application for a permit shall be made on forms furnished by the
Local Administrator and may include, but not be limited to: plans, in duplicate, drawn to
scale and showing: the nature, location, dimensions, and elevations of the area in question;
existing or proposed structures, fill, storage of materials, drainage facilities, and the location
of the foregoing.
B. FEES
All applications for a floodplain development permit shall be accompanied by an application
fee of$ 100.00. In addition, the applicant shall be responsible for reimbursing the Town of
Mamaroneck for any additional costs necessary for review, inspection and approval of this
project. The Local Administrator may require a deposit of no more than $1,500.00 to cover
these additional costs.
C. APPLICATION FOR A PERMIT
The applicant shall provide the following information as appropriate. Additional information may
be required on the permit application form.
10
(1) The proposed elevation, in relation to mean sea level, of the lowest floor(including
basement or cellar) of any new or substantially improved structure to be located in Zones
Al-A30, AE or AH, or Zone A if base flood elevation data are available. Upon completion
of the lowest floor, the permittee shall submit to the Local Administrator the as-built eleva-
tion, certified by a licensed professional engineer or surveyor.
(2) The proposed elevation, in relation to mean sea level, of the bottom of the lowest structural
member of the lowest floor(excluding pilings and columns) of any new or substantially
improved structure to be located in Zones Vl-V30 or VE, or Zone V if base flood elevation
data are available. Upon completion of the lowest floor, the permittee shall submit to the
Local Administrator the as-built elevation, certified by a licensed professional engineer or
surveyor.
(3) The proposed elevation, in relation to mean sea level, to which any new or substantially
improved non-residential structure will be flood proofed. Upon completion of the flood
proofed portion of the structure, the permittee shall submit to the Local Administrator the as-
built flood proofed elevation, certified by a professional engineer or surveyor.
(4) A certificate from a licensed professional engineer or architect that any utility flood proofing
will meet the criteria in Section 110-18 C., UTILITIES.
(5) A certificate from a licensed professional engineer or architect that any non-residential flood
proofed structure will meet the flood proofing criteria in Section 110-21, NON-RESIDEN-
TIAL STRUCTURES.
(6) A description of the extent to which any watercourse will be altered or relocated as a result
of proposed development. Computations by a licensed professional engineer must be
submitted that demonstrate that the altered or relocated segment will provide equal or
greater conveyance than the original stream segment. The applicant must submit any maps,
computations or other material required by the Federal Emergency Management Agency
(FEMA) to revise the documents enumerated in Section 110-6, when notified by the Local
Administrator, and must pay any fees or other costs assessed by FEMA for this purpose. The
applicant must also provide assurances that the conveyance capacity of the altered or
relocated stream segment will be maintained.
(7) A technical analysis, by a licensed professional engineer, if required by the Local
Administrator, which shows whether proposed development to be located in an area of
special flood hazard may result in physical damage to any other property.
(8) In Zone A, when no base flood elevation data are available from other sources, base flood
elevation data shall be provided by the permit applicant for subdivision proposals and other
proposed developments (including proposals for manufactured home and recreational
vehicle parks and subdivisions) that are greater than either 50 lots or 5 acres.
(9) In Zones Vl-V30 and VE, and also Zone V if base flood elevation are available, designs and
specifications, certified by a licensed professional engineer or architect, for any breakaway
walls in a proposed structure with design strengths in excess of 20 pounds per square foot.
11
(10) In Zones Vl-V30 and VE, and also Zone V if base flood elevation are available, for all new
and substantial improvements to structures, flood plain development permit applications
shall be accompanied by design plans and specifications, prepared in sufficient detail to
enable independent review of the foundation support and connection components. Said plans
and specifications shall be developed or reviewed by a licensed professional engineer or
architect, and shall be accompanied by a statement, bearing the signature of the architect or
engineer, certifying that the design and methods of construction to be used are in accordance
with accepted standards of practice and with all applicable provisions of this chapter.
§ 110-13 Duties and Responsibilities of the Local Administrator.
Duties of the Local Administrator shall include, but not be limited to the following.
A. PERMIT APPLICATION REVIEW
The Local Administrator shall conduct the following permit application review before
issuing a floodplain development permit:
(1) Review all applications for completeness, particularly with the requirements of
Section 110-12 C, Application for a Permit, and for compliance with the provisions
and standards of this chapter.
(2) Review subdivision and other proposed new development, including manufactured
home parks to determine whether proposed building sites will be reasonably safe from
flooding. If a proposed building site is located in an area of special flood hazard, all
new construction and substantial improvements shall meet the applicable standards of
Sections 110-14 through 110-24, inclusive, and, in particular, Section 110-16
SUBDIVISION PROPOSALS.
(3) Determine whether any proposed development in an area of special flood hazard may
result in physical damage to any other property (e.g., stream bank erosion and
increased flood velocities). The Local Administrator may require the applicant to
submit additional technical analyses and data necessary to complete the determination.
If the proposed development may result in physical damage to any other property or
fails to meet the applicable requirements of Sections 110-14 through 110-24,
inclusive, no permit shall be issued. The applicant may revise the application to
include measures that mitigate or eliminate the adverse effects and re-submit the
application.
(4) Determine that all necessary permits have been received from those governmental
agencies from which approval is required by State or Federal law.
B. USE OF OTHER FLOOD DATA
(1) When the Federal Emergency Management Agency has designated areas of special
flood hazard on the community's Flood Insurance Rate map (FIRM) but has neither
produced water surface elevation data(these areas are designated Zone A or V on the
12
FIRM) nor identified a floodway, the Local Administrator shall obtain, review and
reasonably utilize any base flood elevation and floodway data available from a
Federal, State or other source, including data developed pursuant to Section 110-12 C,
(7), as criteria for requiring that new construction, substantial improvements or other
proposed development meet the requirements of this law.
(2) When base flood elevation data are not available, the Local Administrator may use
flood information from any other authoritative source, such as historical data, to
establish flood elevations within the areas of special flood hazard, for the purposes of
this law.
C. ALTERATION OF WATERCOURSES
(1) The Local Administrator shall notify adjacent communities and the New York State
Department of Environmental Conservation prior to permitting any alteration or
relocation of a watercourse, and submit evidence of such notification to the Regional
Director, Region II, Federal Emergency Management Agency.
(2) The Local Administrator shall determine whether the permit holder has provided for
maintenance within the altered or relocated portion of said watercourse so that the
flood carrying capacity is not diminished.
D. CONSTRUCTION STAGE
(1) In Zones Al-A30, AE and AH, and also Zone A if base flood elevation data are
available, upon placement of the lowest floor or completion of flood proofing of a new
or substantially improved structure, the Local Administrator shall obtain from the
permit holder a certification of the as-built elevation of the lowest floor or flood
proofed elevation, in relation to mean sea level. The certificate shall be prepared by or
under the direct supervision of a licensed land surveyor or professional engineer and
certified by same. For manufactured homes, the permit holder shall submit the
certificate of elevation upon placement of the structure on the site. A certificate of
elevation must also be submitted for a recreational vehicle if it remains on a site for
180 consecutive days or longer (unless it is fully licensed and ready for highway use).
(2) In Zones Vl-V30 and VE, and also Zone V if base flood elevation data are available,
upon placement of the lowest floor of a new or substantially improved structure, the
permit holder shall submit to the Local Administrator a certificate of elevation, in
relation to mean sea level, of the bottom of the lowest structural member of the lowest
floor(excluding pilings and columns). For manufactured homes, the permit holder
shall submit the certificate of elevation upon placement of the structure on the site. An
elevation certificate must also be submitted for a recreational vehicle if it remains on a
site 180 consecutive days or longer (unless it is fully licensed and ready for highway
use).
(3) Any further work undertaken prior to submission and approval of the certification
shall be at the permit holder's risk. The Local Administrator shall review all data
submitted. Deficiencies detected shall be cause to issue a stop work order for the
project unless immediately corrected.
13
E. INSPECTIONS
The Local Administrator and/or the developer's engineer or architect shall make periodic
inspections at appropriate times throughout the period of construction in order to monitor
compliance with permit conditions and enable said inspector to certify, if requested, that the
development is in compliance with the requirements of the floodplain development permit
and/or any variance provisions.
F. STOP WORK ORDERS
(1) The Local Administrator shall issue, or cause to be issued, a stop work order for any
floodplain development found ongoing without a development permit. Disregard of a stop
work order shall subject the violator to the penalties described in Section 110-9.
(2) The Local Administrator shall issue, or cause to be issued, a stop work order for any
floodplain development found non-compliant with the provisions of this law and/or the
conditions of the development permit. Disregard of a stop work order shall subject the
violator to the penalties described in Section 110-9.
G. CERTIFICATE OF COMPLIANCE
(1) In areas of special flood hazard, as determined by documents enumerated in Section
110-6, it shall be unlawful to occupy or to permit the use or occupancy of any building
or premises, or both, or part thereof hereafter created, erected, changed, converted or
wholly or partly altered or enlarged in its use or structure until a certificate of
compliance has been issued by the Local Administrator stating that the building or
land conforms to the requirements of this chapter.
(2) A certificate of compliance shall be issued by the Local Administrator upon
satisfactory completion of all development in areas of special flood hazard.
(3) Issuance of the certificate shall be based upon the inspections conducted as prescribed
in Section 110-13 E., INSPECTIONS, and/or any certified elevations, hydraulic data,
flood proofing, anchoring requirements or encroachment analyses which may have
been required as a condition of the approved permit.
H. INFORMATION TO BE RETAINED
The Local Administrator shall retain and make available for inspection, copies of the
following:
(1) Floodplain development permits and certificates of compliance;
(2) Certifications of as-built lowest floor elevations of structures, required pursuant to
Sections 110-13 D. (1) and 110-13 D. (2), and whether or not the structures contain a
basement;
14
(3) Flood proofing certificates required pursuant to Section 110-13 D. (1), and whether or
not the structures contain a basement;
(4) Variances issued pursuant to Section 110-25, APPEALS BOARD; and, Section 110-
26, CONDITIONS FOR VARIANCES, and,
(5) Notices required under Section 110-13 C., ALTERATION OF WATERCOURSES.
§ 110-14 GENERAL CONSTRUCTION STANDARDS
The following standards apply to new development, including new and substantially improved
structures, in the areas of special flood hazard shown on the Flood Insurance Rate Map designated
in Section 110-6.
§ 110-15 COASTAL HIGH HAZARD AREAS
The following requirements apply within Zones V1-V30, VE and V:
(1) All new construction, including manufactured homes and recreational vehicles on site 180
days or longer and not fully licensed for highway use, shall be located landward of the reach
of high tide.
(2) The use of fill for structural support of buildings, manufactured homes or recreational
vehicles on site 180 days or longer is prohibited.
(3) Man-made alteration of sand dunes which would increase potential flood damage is
prohibited.
§ 110-16 SUBDIVISION PROPOSALS
The following standards apply to all new subdivision proposals and other proposed development
in areas of special flood hazard (including proposals for manufactured home and recreational
vehicle parks and subdivisions):
(1) Proposals shall be consistent with the need to minimize flood damage;
(2) Public utilities and facilities such as sewer, gas, electrical and water systems shall be located
and constructed so as to minimize flood damage; and,
(3) Adequate drainage shall be provided to reduce exposure to flood damage.
§ 110-17 ENCROACHMENTS
(1) Within Zones Al-A30 and AE, on streams without a regulatory floodway, no new
construction, substantial improvements or other development (including fill) shall be
permitted unless:
(i) the applicant demonstrates that the cumulative effect of the proposed
development, when combined with all other existing and anticipated
15
development, will not increase the water surface elevation of the base flood
more than one foot at any location, or,
(ii) the Town of Mamaroneck agrees to apply to the Federal Emergency
Management Agency (FEMA)for a conditional FIRM revision, FEMA approval
is received and the applicant provides all necessary data, analyses and mapping
and reimburses the Town of Mamaroneck for all fees and other costs in relation
to the application. The applicant must also provide all data, analyses and
mapping and reimburse the Town of Mamaroneck for all costs related to the
final map revision.
(2) On streams with a regulatory floodway, as shown on the Flood Boundary and
Floodway Map or the Flood Insurance Rate Map adopted in Section 110-6, no new
construction, substantial improvements or other development in the floodway
(including fill) shall be permitted unless:
(i) a technical evaluation by a licensed professional engineer shows that such an
encroachment shall not result in any increase in flood levels during occurrence
of the base flood, or,
(ii) the Town of Mamaroneck agrees to apply to the Federal Emergency
Management Agency (FEMA) for a conditional FIRM and floodway revision,
FEMA approval is received and the applicant provides all necessary data,
analyses and mapping and reimburses the Town of Mamaroneck for all fees and
other costs in relation to the application. The applicant must also provide all
data, analyses and mapping and reimburse the Town of Mamaroneck for all
costs related to the final map revisions.
(3) Whenever any portion of a floodplain is authorized for development, volume of
space occupied by the authorized fill structure below the base flood elevation shall
be compensated for and balanced by a hydraulically equivalent volume of excavation
taken from below the base flood elevation at or adjacent to the development site. All
such excavations shall be constructed to drain freely to the watercourse. No area
below the waterline of a pond or other body of water can be credited as a
compensating excavation.
§ 110-18 STANDARDS FOR ALL STRUCTURES
A. ANCHORING
New structures and substantial improvement to structures in areas of special flood hazard
shall be anchored to prevent flotation, collapse, or lateral movement during the base flood.
This requirement is in addition to applicable State and local anchoring requirements for
resisting wind forces.
16
B. CONSTRUCTION MATERIALS AND METHODS
(1) New construction and substantial improvements to structures shall be constructed with
materials and utility equipment resistant to flood damage.
(2) New construction and substantial improvements to structures shall be constructed
using methods and practices that minimize flood damage.
(3) For enclosed areas below the lowest floor of a structure within Zones Al-A30, AE or
AH, and also Zone A if base flood elevation data are available, new and substantially
improved structures shall have fully enclosed areas below the lowest floor that are use-
able solely for parking of vehicles, building access or storage in an area other than a
basement and which are subject to flooding, designed to automatically equalize
hydrostatic flood forces on exterior walls by allowing for the entry and exit of flood -
waters. Designs for meeting this requirement must either be certified by a licensed
professional engineer or architect or meet or exceed the following minimum criteria:
(i) a minimum of two openings having a total net area of not less than one
square inch for every square foot of enclosed area subject to flooding; and
(ii) the bottom of all such openings no higher than one foot above the lowest
adjacent finished grade.
Openings may be equipped with louvers, valves, screens or other coverings or devices
provided they permit the automatic entry and exit of floodwaters. Enclosed areas sub-
grade on all sides are considered basements and are not permitted.
(4) Within Zones Vl-V30 and VE, and also within Zone V if base flood elevation are
available, new construction and substantial improvements shall have the space below
the lowest floor either free from obstruction or constructed with non-supporting
breakaway walls, open wood lattice-work or insect screening intended to collapse
under wind and water loads without causing collapse, displacement, or other structural
damage to the elevated portion of the building or supporting foundation system.The
enclosed space below the lowest floor shall be used only for parking vehicles, building
access or storage. Use of this space for human habitation is expressly prohibited. The
construction of stairs, stairwells and elevator shafts are subject to the design
requirements for breakaway walls.
C. UTILITIES
(1) New and replacement electrical equipment, heating, ventilating, air conditioning,
plumbing connections, and other service equipment shall be located at or above the
base flood elevation. Electrical wiring and outlets, switches,junction boxes and
panels shall be elevated to or above the base flood elevation unless they conform to
the appropriate provisions of the electrical part of the Building Code of New York
17
State or the Residential Code of New York State for location of such items in wet
locations;
(2) New and replacement water supply systems shall be designed to minimize or eliminate
infiltration of flood waters into the system;
(3) New and replacement sanitary sewage systems shall be designed to minimize or
eliminate infiltration of flood waters. Sanitary sewer and storm drainage systems for
buildings that have openings below the base flood elevation shall be provided with
automatic backflow valves or other automatic backflow devices that are installed in
each discharge line passing through a building's exterior wall; and,
(4) On-site waste disposal systems shall be located to avoid impairment to them or
contamination from them during flooding.
§ 110-19 STANDARDS FOR RESIDENTIAL STRUCTURES OUTSIDE COASTAL HIGH
HAZARD AREAS
A. ELEVATION
The following standards, in addition to the standards in Section 110-16, SUBDIVISION
PROPOSALS, Section 110-17, ENCROACHMENTS and Section 110-18, STANDARDS
FOR ALL STRUCTURES, apply to structures located in areas of special flood hazard as
indicated.
(1) Within Zones Al-A30, AE and AH and also Zone A if base flood elevation data are
available, new construction and substantial improvements shall have the lowest floor
(including basement) elevated to or above two feet above the base flood level.
(2) Within Zone A, when no base flood elevation data are available, new and substantially
improved structures shall have the lowest floor (including basement) elevated at least
three feet above the highest adjacent grade.
(3) Within Zone AO, new and substantially improved structures shall have the lowest
floor(including basement) elevated above the highest adjacent grade at least as high as
two feet above the depth number specified in feet on the community's Flood Insurance
Rate Map enumerated in Section 110-6 (at least two feet if no depth number is speci-
fied).
(4) Within Zones AH and AO, adequate drainage paths are required to guide flood waters
around and away from proposed structures on slopes.
§ 110-20 STANDARDS FOR RESIDENTIAL STRUCTURES WITHIN COASTAL HIGH
HAZARD AREAS
The following standards, in addition to the standards in Section 110-15, COASTAL HIGH HAZARD
AREAS, and Section 110-16, SUBDIVISION PROPOSALS, Section 110-17, ENCROACHMENTS
and Section 110-18, STANDARDS FOR ALL STRUCTURES, apply to structures located in areas of
18
special flood hazard shown as Zones V1-V30, VE or V on the community's Flood Insurance Rate Map
designated in Section 110-6.
A. ELEVATION
New construction and substantial improvements shall be elevated on pilings, columns or
shear walls such that the bottom of the lowest horizontal structural member supporting the
lowest elevated floor(excluding columns, piles, diagonal bracing attached to the piles or
columns, grade beams, pile caps and other members designed to either withstand storm action
or break away without imparting damaging loads to the structure)is elevated to or above two
feet above base flood level so as not to impede the flow of water.
B. DETERMINATION OF LOADING FORCES
Structural design shall consider the effects of wind and water loads acting simultaneously
during the base flood on all building components.
(1) The structural design shall be adequate to resist water forces that would occur during the
base flood. Horizontal water loads considered shall include inertial and drag forces of
waves, current drag forces, and impact forces from waterborne storm debris. Dynamic
uplift loads shall also be considered if bulkheads, walls, or other natural or man-made
flow obstructions could cause wave run-up beyond the elevation of the base flood.
(2) Buildings shall be designed and constructed to resist the forces due to wind pressure.
Wind forces on the superstructure include windward and leeward forces on vertical walls,
uplift on the roof, internal forces when openings allow wind to enter the house, and
upward force on the underside of the house when it is exposed. In the design, the wind
should be assumed to blow potentially from any lateral direction relative to the house.
(3) Wind loading values used shall be those required by the building code.
C. FOUNDATION STANDARDS
(1) The pilings or column foundation and structure attached thereto shall be adequately
anchored to resist flotation, collapse or lateral movement due to the effects of wind and
water pressures acting simultaneously on all building components. Foundations must be
designed to transfer safely to the underlying soil all loads due to wind, water, dead load,
live load and other loads (including uplift due to wind and water).
(2) Spread footings and fill material shall not be used for structural support of a new building
or substantial improvement of an existing structure.
D. PILE FOUNDATION DESIGN
(1) The design ratio of pile spacing to pile diameter shall not be less than 8:1 for individual
piles (this shall not apply to pile clusters located below the design grade). The maximum
center-to-center spacing of wood piles shall not be more than 12 feet on center under load
bearing sills, beams, or girders.
17
(2) Pilings shall have adequate soil penetration (bearing capacity) to resist the combined
wave and wind loads (lateral and uplift) associated with the base flood acting simul-
taneously with typical structure(live and dead) loads, and shall include consideration of
decreased resistance capacity caused by erosion of soil strata surrounding the piles. The
minimum penetration for foundation piles is to an elevation of 5 feet below mean sea
level (msl) datum if the BFE is +10 msl or less, or to be at least 10 feet below msl if the
BFE is greater than+10 msl.
(3) Pile foundation analysis shall also include consideration of piles in column action from
the bottom of the structure to the stable soil elevation of the site. Pilings may be
horizontally or diagonally braced to withstand wind and water forces.
(4) The minimum acceptable sizes for timber piles are a tip diameter of 8 inches for round
timber piles and 8 by 8 inches for square timber piles. All wood piles must be treated in
accordance with requirements of EPEE-C3 to minimize decay and damage from fungus.
(5) Reinforced concrete piles shall be cast of concrete having a 28-day ultimate compressive
strength of not less than 5,000 pounds per square inch, and shall be reinforced with a
minimum of four longitudinal steel bars having a combined area of not less than 1% nor
more than 4% of the gross concrete area. Reinforcing for precast piles shall have a
concrete cover of not less than 1 1/4 inches for No. 5 bars and smaller and not less than 1
1/2 inches for No. 6 through No. 11 bars. Reinforcement for piles cast in the field shall
have a concrete cover of not less than 2 inches.
(6) Piles shall be driven by means of a pile driver or drop hammer,jetted, or augered into
place.
(7) Additional support for piles in the form of bracing may include lateral or diagonal brac-
ing between piles.
(8) When necessary, piles shall be braced at the ground line in both directions by a wood
timber grade beam or a reinforced concrete grade beam. These at-grade supports should
be securely attached to the piles to provide support even if scoured from beneath.
(9) Diagonal bracing between piles, consisting of 2-inch by 8-inch (minimum) members
bolted to the piles, shall be limited in location to below the lowest supporting structural
member and above the stable soil elevation, and aligned in the vertical plane along pile
rows perpendicular to the shoreline. Galvanized steel rods (minimum diameter 1/2 inch)
or cable type bracing is permitted in any plane.
(10)Knee braces, which stiffen both the upper portion of a pile and the beam-to-pile
connection, may be used along pile rows perpendicular and parallel to the shoreline.
Knee braces shall be 2-by-8 lumber bolted to the sides of the pile/beam, or 4-by-4 or
larger braces framed into the pile/beam. Bolting shall consist of two 5/8-inch galvanized
steel bolts (each end) for 2-by-8 members, or one 5/8-inch lag bolt (each end) for square
members. Knee braces shall not extend more than 3 feet below the elevation of the base
flood.
18
E. COLUMN FOUNDATION DESIGN
Masonry piers or poured-in-place concrete piers shall be internally reinforced to resist
vertical and lateral loads, and be connected with a moment-resisting connection to a pile
cap or pile shaft.
F. CONNECTORS AND FASTENERS
Galvanized metal connectors, wood connectors, or bolts of size and number adequate for
the calculated loads must be used to connect adjoining components of a structure. Toe
nailing as a principal method of connection is not permitted. All metal connectors and
fasteners used in exposed locations shall be steel, hot-dipped galvanized after fabrication.
Connectors in protected interior locations shall be fabricated from galvanized sheet.
G. BEAM TO PILE CONNECTIONS
The primary floor beams or girders shall span the supports in the direction parallel to the
flow of potential floodwater and wave action and shall be fastened to the columns or
pilings by bolting, with or without cover plates. Concrete members shall be connected by
reinforcement, if cast in place, or(of precast) shall be securely connected by bolting and
welding. If sills, beams, or girders are attached to wood piling at a notch, a minimum of
two (5/8)-inch galvanized steel bolts or two hot-dipped galvanized straps 3/16 inch by 4
inches by 18 inches each bolted with two 1/2 inch lag bolts per beam member shall be
used. Notching of pile tops shall be the minimum sufficient to provide ledge support for
beam members without unduly weakening pile connections. Piling shall not be notched
so that the cross section is reduced below 50%.
H. FLOOR AND DECK CONNECTIONS
(1) Wood 2- by 4-inch (minimum) connectors or metal joist anchors shall be used to tie floor
joists to floor beams/girders. These should be installed on alternate floor joists, at a
minimum. Cross bridging of all floor joists shall be provided. Such cross bridging may
be 1- by 3-inch members, placed 8 feet on-center maximum, or solid bridging of same
depth as joist at same spacing.
(2) Plywood should be used for sub flooring and attic flooring to provide good torsional
resistance in the horizontal plane of the structure. The plywood should not be les than
(3/4)-inch total thickness, and should be exterior grade and fastened to beams or joists
with 8d annular or spiral thread galvanized nails. Such fastening shall be supplemented
by the application of waterproof industrial adhesive applied to all bearing surfaces.
I. EXTERIOR WALL CONNECTIONS
All bottom plates shall have any required breaks under a wall stud or an anchor bolt.
Approved anchors will be used to secure rafters or joists and top and bottom plates to
studs in exterior and bearing walls to form a continuous tie. Continuous 15/32-inch or
thicker plywood sheathing--overlapping the top wall plate and continuing down to the
sill, beam, or girder--may be used to provide the continuous tie. If the sheets of plywood
are not vertically continuous, then 2-by-4 nailer blocking shall be provided at all horizon-
19
tal joints. In lieu of the plywood, galvanized steel rods of 1/2-inch diameter or
galvanized steel straps not less than 1 inch wide by 1/16 inch thick may be used to
connect from the top wall plate to the sill, beam, or girder. Washers with a minimum
diameter of 3 inches shall be used at each end of the 1/2-inch round rods. These anchors
shall be installed no more than 2 feet from each corner rod, no more than 4 feet on center.
J. CEILING JOIST/RAFTER CONNECTIONS
All ceiling joists or rafters shall be installed in such a manner that the joists provide a
continuous tie across the rafters. Ceiling joists and rafters shall be securely fastened at
their intersections. A metal or wood connector shall be used at alternate ceiling
joist/rafter connections to the wall top plate.
Gable roofs shall be additionally stabilized by installing 2-by-4 blocking on 2-foot
centers between the rafters at each gable end. Blocking shall be installed a minimum of 8
feet toward the house interior from each gable end.
K. PROJECTING MEMBERS
All cantilevers and other projecting members must be adequately supported and braced to
withstand wind and water uplift forces. Roof eave overhangs shall be limited to a
maximum of 2 feet and joist overhangs to a maximum of 1 foot. Larger overhangs and
porches will be permitted if designed or reviewed by a registered professional engineer or
architect and certified in accordance with thus chapter.
L. ROOF SHEATHING
(1) Plywood, or other wood material, when used as roof sheathing, shall not be less than
15/32 inch in thickness, and shall be of exterior sheathing grade or equivalent. All
attaching devices for sheathing and roof coverings shall be galvanized or be of other
suitable corrosion resistant material.
(2) All corners, gable ends, and roof overhangs exceeding six inches shall be reinforced by
the application of waterproof industrial adhesive applied to all bearing surfaces of any
plywood sheet used in the sheathing of such corner, gable end, or roof overhang.
(3) In addition, roofs should be sloped as steeply as practicable to reduce uplift pressures,
and special care should be used in securing ridges, hips, valleys, eaves, vents, chimneys,
and other points of discontinuity in the roofing surface.
M. PROTECTION OF OPENINGS
All exterior glass panels, windows, and doors shall be designed, detailed, and constructed
to withstand loads due to the design wind speed of 75 mph. Connections for these
elements must be designed to transfer safely the design loads to the supporting structure.
Panel widths of multiple panel sliding glass doors shall not exceed three feet.
20
N. BREAKAWAY WALL DESIGN STANDARDS
(1) The breakaway wall shall have a design safe loading resistance of not less than 10 and
not more than 20 pounds per square foot, with the criterion that the safety of the overall
structure at the point of wall failure be confirmed using established procedures. Grade
beams shall be installed in both directions for all piles considered to carry the breakaway
wall load. Knee braces are required for front row piles that support breakaway walls.
(2) Use of breakaway wall strengths in excess of 20 pounds per square foot shall not be
permitted unless a registered professional engineer or architect has developed or re-
viewed the structural design and specifications for the building foundation and
breakaway wall components, and certifies that (1) the breakaway walls will fail under
water loads less than those that would occur during the base flood; and (2) the elevated
portion of the building and supporting foundation system will not be subject to collapse,
displacement, or other structural damage due to the effects of wind and water loads acting
simultaneously on all building components (structural and non-structural). Water loading
values used shall be those associated with the base flood. Wind loading values shall be
those required by the building code.
§ 110-21 STANDARDS FOR NON-RESIDENTIAL STRUCTURES OUTSIDE COASTAL
HIGH HAZARD AREAS
The following standards apply to new and substantially improved commercial, industrial and
other non-residential structures, in addition to the requirements in Section 110-16,
SUBDIVISION PROPOSALS, Section 110-17, ENCROACHMENTS and Section 110-18,
STANDARDS FOR ALL STRUCTURES.
(1) Within Zones Al-A30, AE and AH, and also Zone A if base flood elevation data are
available, new construction and substantial improvements of any non-residential
structure, together with attendant utility and sanitary facilities, shall either:
(i) have the lowest floor, including basement or cellar, elevated to or above two feet
above the base flood elevation; or
(ii) be flood proofed so that the structure is water tight below two feet above the base
flood level with walls substantially impermeable to the passage of water. All
structural components located below the base flood level must be capable of resisting
hydrostatic and hydrodynamic loads and the effects of buoyancy.
(2) Within Zone AO, new construction and substantial improvements of non-residential
structures shall:
(i) have the lowest floor(including basement) elevated above the highest adjacent
grade at least as high as two feet above the depth number specified in feet on the
community's FIRM (at least two feet if no depth number is specified), or
(ii) together with attendant utility and sanitary facilities, be completely flood proofed
to that level to meet the flood proofing standard specified in this chapter.
21
(3) If the structure is to be flood proofed, a licensed professional engineer or architect shall
develop and/or review structural design, specifications, and plans for construction. A
Flood proofing Certificate or other certification shall be provided to the Local
Administrator that certifies the design and methods of construction are in accordance
with accepted standards of practice for meeting the provisions of this chapter, including
the specific elevation (in relation to mean sea level) to which the structure is to be flood
proofed.
(4) Within Zones AH and AO, adequate drainage paths are required to guide flood waters
around and away from proposed structures on slopes.
(5) Within Zone A, when no base flood elevation data are available, the lowest floor
(including basement) shall be elevated at least three feet above the highest adjacent
grade.
§ 110-22 STANDARDS FOR NON-RESIDENTIAL STRUCTURES WITHIN COASTAL
HIGH HAZARD AREAS
In Zones V1-V30, VE and also Zone V if base flood elevations are available, new construction and
substantial improvements of any non-residential structure, together with attendant utility and sanitary
facilities, shall have the bottom of lowest member of the lowest floor elevated to or above the base flood
elevation. Flood proofing of structures is not an allowable alternative to elevating the lowest floor to the
base flood elevation in Zones V1-V30, VE and V.
§ 110-23 CRITICAL FACILITIES
In order to prevent potential flood damage to certain facilities that would result in serious
danger to life and health, or widespread social or economic dislocation, no new critical
facility shall be located within any Area of Special Flood Hazard, or within any 500-year flood zone
shown as a B zone or a Shaded X zone on the Community's Flood Insurance Rate Maps.
§ 110-24 MANUFACTURED HOMES AND RECREATIONAL VEHICLES
The following standards in addition to the standards in Section 110-14, GENERAL STANDARDS, and
Section 110-18, STANDARDS FOR ALL STRUCTURES apply, as indicated, in areas of special flood
hazard to manufactured homes and to recreational vehicles which are located in areas of special flood
hazard.
(1) Recreational vehicles placed on sites within Zones Al-A30, AE, AH, V1-V30, V, and
VE shall either:
(i) be on site fewer than 180 consecutive days,
(ii) be fully licensed and ready for highway use, or
(iii) meet the requirements for manufactured homes in paragraphs (2), (3) and (4) of
Section 110-21.
22
A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is
attached to the site only by quick disconnect type utilities and security devices and has no
permanently attached additions.
(2) A manufactured home that is placed or substantially improved in Zones Al-A30, AE,
AH, VI-V30, V, and VE shall be elevated on a permanent foundation such that the
lowest floor is elevated to or above the base flood elevation and is securely anchored to
an adequately anchored foundation system to resist flotation, collapse and lateral
movement. Elevation on piers consisting of dry stacked blocks is prohibited.
(3) Within Zones A or V, when no base flood elevation data are available, new and
substantially improved manufactured homes shall be elevated such that the manufactured
home chassis is supported by reinforced piers or other foundation elements of at least
equivalent strength that are no less than 36 inches in height above grade and are securely
anchored to an adequately anchored foundation system to resist flotation, collapse or
lateral movement. Elevation on piers consisting of dry stacked blocks is prohibited.
(4) Within Zone AO, the floor shall be elevated above the highest adjacent grade at least as
high as the depth number specified on the Flood Insurance Rate Map enumerated in
Section 3.2 (at least two feet if no depth number is specified). Elevation on piers
consisting of dry stacked blocks is prohibited.
§ 110-25 APPEALS BOARD
(1) The Planning Board as established by the Town of Mamaroneck shall hear and decide
appeals and requests for variances from the requirements of this chapter.
(2) The Planning Board shall hear and decide appeals when it is alleged there is an error in
any requirement, decision, or determination made by the Local Administrator in the
enforcement or administration of this chapter.
(3) Those aggrieved by the decision of the Planning Board may appeal such decision to the
Supreme Court pursuant to Article 78 of the Civil Practice Law and Rules.
(4) In passing upon such applications, the Planning Board, shall consider all technical
evaluations, all relevant factors, standards specified in other sections of this chapter and:
(i) the danger that materials may be swept onto other lands to the injury of others;
(ii) the danger to life and property due to flooding or erosion damage;
(iii) the susceptibility of the proposed facility and its contents to flood damage and the
effect of such damage on the individual owner;
(iv) the importance of the services provided by the proposed facility to the
community;
(v) the necessity to the facility of a waterfront location, where applicable;
23
(vi) the availability of alternative locations for the proposed use which are not subject
to flooding or erosion damage;
(vii) the compatibility of the proposed use with existing and anticipated development;
(viii) the relationship of the proposed use to the comprehensive plan and floodplain
management program of that area;
(ix) the safety of access to the property in times of flood for ordinary and emergency
vehicles;
(x) the costs to local governments and the dangers associated with conducting search
and rescue operations during periods of flooding;
(xi) the expected heights, velocity, duration, rate of rise and sediment transport of the
flood waters and the effects of wave action, if applicable, expected at the site; and
(xii) the costs of providing governmental services during and after flood conditions,
including search and rescue operations, maintenance and repair of public utilities and
facilities such as sewer, gas, electrical, and water systems and streets and bridges.
(5) Upon consideration of the factors of Section 110-25 (4) and the purposes of this chapter,
the Planning Board may attach such conditions to the granting of variances as it deems
necessary to further the purposes of this chapter.
(6) The Local Administrator shall maintain the records of all appeal actions including
technical information and report any variances to the Federal Emergency Management
Agency upon request.
§ 110-26 CONDITIONS FOR VARIANCES
(1) Generally, variances may be issued for new construction and substantial improvements to
be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots
with existing structures constructed below the base flood level, providing items (i-xii) in
Section 110-25 (4)have been fully considered. As the lot size increases beyond the one-
half acre, the technical justification required for issuing the variance increases.
(2) Variances may be issued for the repair or rehabilitation of historic structures upon
determination that:
(i) the proposed repair or rehabilitation will not preclude the structure's continued
designation as a "Historic structure".
(ii) the variance is the minimum necessary to preserve the historic character and
design of the structure.
24
(3) Variances may be issued by a community for new construction and substantial
improvements and for other development necessary for the conduct of a functionally
dependent use provided that:
(i) the criteria of paragraphs (1), (4), (5) and (6) of Section 110-26 are met;
(ii) the structure or other development is protected by methods that minimize flood
damages during the base flood and create no additional threat to public safety.
(4) Variances shall not be issued within any designated floodway if any increase in flood
levels during the base flood discharge would result.
(5) Variances shall only be issued upon a determination that the variance is the minimum
necessary, considering the flood hazard, to afford relief.
(6) Variances shall only be issued upon receiving written justification of-
(i) a showing of good and sufficient cause;
(ii) a determination that failure to grant the variance would result in exceptional
hardship to the applicant; and
(iii) a determination that the granting of a variance will not result in increased flood
heights, additional threats to public safety, extraordinary public expense, create
nuisances, cause fraud on or victimization of the public or conflict with existing local
laws or ordinances.
(7) Any applicant to whom a variance is granted for a building with the lowest floor below
the base flood elevation shall be given written notice over the signature of a community
official that the cost of flood insurance will be commensurate with the increased risk
resulting from lowest floor elevation.
25
Be it enacted this day of 20 by the
of the
County, New York, to be effective
SEAL
ATTEST CLERK
26
Attachment A
MODEL FLOODPLAIN DEVELOPMENT
APPLICATION FORM
27
APPLICATION 4 Page 1 of 4
FLOODPLAIN DEVELOPMENT PERMIT APPLICATION
This form is to be filled out in duplicate.
SECTION 1:GENERAL PROVISIONS (APPLICANT to read and sign):
1. No work may start until a permit is issued.
2. The permit may be revoked if any false statements are made herein.
3. If revoked, all work must cease until permit is re-issued.
4. Development shall not be used or occupied until a Certificate of Compliance is issued.
5. The permit is invalid if no work is commenced within six months of issuance,and expires 2 years from date of
issuance.
6. Applicant is hereby informed that other permits may be required to fulfill local, state and federal regulatory
requirements.
7. Applicant hereby gives consent to the Local Administrator or his/her representative to make reasonable inspections
required to verify compliance.
8. I,THE APPLICANT,CERTIFY THAT ALL STATEMENTS HEREIN AND IN ATTACHMENTS TO THIS
APPLICATION ARE,TO THE BEST OF MY KNOWLEDGE,TRUE AND ACCURATE.
(APPLICANT'S SIGNATURE) DATE
SECTION 2:PROPOSED DEVELOPMENT(To be completed by APPLICANT)
NAME ADDRESS TELEPHONE
APPLICANT
BUILDER
ENGINEER
PROJECT LOCATION:
To avoid delay in processing the application,please provide enough information to easily identify the project location.
Provide the street address,lot number or legal description(attach)and,outside urban areas,the distance to the nearest
intersecting road or well-known landmark. A map attached to this application,and a sketch showing the project layout would
be helpful.
28
APPLICATION 4 PAGE 2 of 4
DESCRIPTION OF WORK(Check all applicable boxes):
A. STRUCTURAL DEVELOPMENT
ACTIVITY STRUCTURE TYPE
)ylimaF 4-1(laitnediseR erutcurtS weN
)ylimaF 4 naht eroM(laitnediseR noitiddA
)seY G ?gnifoorpdoolF(laitnediser-noN noitaretlA
)laicremmoC&laitnediseR(esU denibmoC noitacoleR
emoH)eliboM(derutcafunaM noitilomeD
)oN seY ?kraP emoH derutcafunaM nl( tnemecalpeR
ESTIMATED COST OF PROJECT$
B. OTHER DEVELOPMENT ACTIVITIES:
Fill Mining Drilling Grading
Excavation(Except for Structural Development Checked Above)
Watercourse Alteration(Including Dredging and Channel Modifications)
Drainage Improvements(Including Culvert Work), Stormwater Control Structures or Ponds
Road, Street or Bridge Construction
Subdivision(New or Expansion)
Individual Water or Sewer System
Other(Please Specify)
After completing SECTION 2,APPLICANT should submit form to Local Administrator for review.
SECTION 3: FLOODPLAIN DETERMINATION (To be completed by LOCAL ADMINISTRATOR)
The proposed development is located on FIRM Panel No. Dated
The Proposed Development:
The proposed development is reasonably safe from flooding. Entire property is in Zone B,C or X.
The proposed development is in adjacent to a flood prone area.
100-Year flood elevation at the site is:
Ft. NGVD 1929/ NAVD 1988 (MSL)
Unavailable
See Section 4 for additional instructions for development that is or may be in a flood prone area.
SIGNED DATE
29
APPLICATION 4 PAGE 3 of 4
SECTION 4:ADDITIONAL INFORMATION REQUIRED(To be completed by LOCAL ADMINISTRATOR)
The applicant must submit the documents checked below before the application can be processed:
A site plan showing the location of all existing structures,water bodies, adjacent roads,lot dimensions and
proposed development.
Development plans and specifications,drawn to scale,including where applicable: details for anchoring
structures,proposed elevation of lowest floor(including basement),types of water resistant materials used
below the first floor,details of floodproofing of utilities located below the first floor,details of enclosures below
the first floor,openings in foundation for entry and exit of floodwaters.
Other
Elevation Certificate
Subdivision or other development plans(If the subdivision or other development exceeds 50 lots or 5 acres,
whichever is the lesser,the applicant must provide 100-year flood elevations if they are not otherwise
available).
Plans showing the watercourse location,proposed relocations,Floodway location.
Topographic information showing existing and proposed grades,location of all proposed fill.
Top of new fill elevation Ft. NGVD 1929/ NAVD 1988 (MSL)
PE Certification of Soil Compaction
Floodproofing protection level(non-residential only) NGVD 1929/ NAVD 1988 (MSL)
For floodproofed structures,applicant must attach certification from registered engineer or architect.
Other:
SECTION 5: PERMIT DETERMINATION(To be completed by LOCAL ADMINISTRATOR)
I have determined that the proposed activity: A. Is
B. Is not
conforms to the provisions of Chapter 110(Flood Damage Prevention)of the Code of the Town of Mamaroneck. This
permit is hereby issued subject to the conditions attached to and made part of this permit.
SIGNED DATE
If BOX A is checked,the Local Administrator may issue a Development Permit upon payment of designated fee.
If BOX B is checked,the Local Administrator will provide a written summary of deficiencies. Applicant may revise and
resubmit an application to the Local Administrator or may request a hearing from the
Expiration Date:
30
APPLICATION 4 PAGE 4 of 4
APPEALS: Appealed to ?oN seY
Hearing date:
Decision---Approved? oN seY
Conditions:
SECTION 6: AS-BUILT ELEVATIONS(To be submitted by APPLICANT before Certificate of Compliance is issued)
The following information must be provided for project structures. This section must be completed by a registered
professional engineer or a licensed land surveyor(or attach a certification to this application). Complete 1 or 2 below.
1. Actual(As-Built)Elevation of the top of the lowest floor,including basement(in Coastal High Hazard Areas,bottom
of lowest structural member of the lowest floor,excluding piling and columns)is: FT. NGVD
1929/
NAVD 1988 (MSL).
Attach Elevation Certificate FEMA Form 81-31
2. Actual(As-Built)Elevation of floodproofing protection is FT. NGVD 1929/ NAVD 1988 (MSL).
Attach Floodproofing Certificate FEMA Form 81-65
NOTE: Any work performed prior to submittal of the above information is at the risk of the Applicant.
SECTION 7: COMPLIANCE ACTION(To be completed by LOCAL ADMINISTRATOR)
The LOCAL ADMINISTRATOR will complete this section as applicable based on inspection of the project to ensure
compliance with the community's local law for flood damage prevention.
INSPECTIONS: DATE BY DEFICIENCIES? YES NO
DATE BY DEFICIENCIES? YES NO
DATE BY DEFICIENCIES? YES NO
SECTION 8: CERTIFICATE OF COMPLIANCE(To be completed by LOCAL ADMINISTRATOR)
Certificate of Compliance issued: DATE:
BY:
31
Attachment B
SAMPLE
CERTIFICATE OF COMPLIANCE
for Development in a Special Flood Hazard Area
32
CERTIFICATE OF COMPLIANCE
FOR DEVELOPMENT IN A SPECIAL FLOOD HAZARD AREA
(Owner Must Retain This Certificate)
Premises located at:
Owner:
Owner's Address:
Permit No. Permit Date:
Check One:
_New Building
_Existing Building
_Fill
Other:
The Local Administrator is to complete a. or b. below:
a. Compliance is hereby certified with the requirements of Chapter 110 (Flood Damage Prevention)
of the Code of the Town of Mamaroneck
Signed: Dated:
b. Compliance is hereby certified with the requirements of Chapter 110 (Flood Damage Prevention)
of the Code of the Town of Mamaroneck, as modified by variance no. dated
Signed: Dated:
33
Section 3 —Severability:
Should any provision of this Local Law be declared invalid or unconstitutional by any court of
competent jurisdiction, such declaration of unconstitutionality or invalidity shall not affect any
other provisions of this Local Law, which may be implemented without the invalid or
unconstitutional provisions.
Section 4 —Effective Date:
This Local Law shall become effective on the later of(a) the date it is filed with the Secretary of
State or(b) September 28, 2007.
2007 LL No. (Flood Damage Prevention)-F approved 07-11-07
34