HomeMy WebLinkAbout2025_08_25 Coastal Zone Management Commission Minutes
Town of Mamaroneck - Village of Larchmont
Coastal Zone Management Commission
Town Center: 740 West Boston Post Road, Mamaroneck, NY 10543-3353
Tel: 914-381-7845 Fax: 914-381-8473 conservationdept@townofmamaroneckny.org
CZMC Minutes
Monday, August 25, 2025
1. Roll Call and Introductions
The meeting was called to order at 7:35pm.
CZMC Members:
Dr. C. Alan Mason, Chairman
Matthew Teitsch
Colin Barrett
Tara Anderson
Others Present:
Elizabeth Aitchison, Environmental Planner, Town of Mamaroneck
John M. Knoetgen, Architect, 7 Evergreen Lane
Nicholas Shirriah, Consulting Engineer, 7 Evergreen Lane
Pierre Sarrazin, Architect, 398 Weaver Street
Bill Kenny, Landscape Architect, 398 Weaver Street
Shea Graham, Consulting Engineer, 398 Weaver Street
Grant Whittington, Propel NY Energy
Kathleen Marean, Propel NY Energy
Katie Axa, Propel NY Energy
Edward J. Birdie, NY Power Authority
Susan Craig, Mamaroneck Resident for Propel Project
2. Approval of Minutes
2.1. Approval of Minutes - June 23, 2025
Approval of the minutes tabled until September.
3. Referrals
3.1. 7 Evergreen Lane - Residential Site Plan and Tree Removal Permit Applications for the
construction of a new single family house.
John Knoetgen, Architect and Nicholas Shirriah, Engineer presented the proposal to
construct a new single-family house at 7 Evergreen Lane. The original 3-story house
burned down and a new single-story house will be built in the same location.
The wetlands and watercourse on the property were flagged by a wetlands
consultant. Part of the watercourse is piped underground and daylights in a large
detention area with a controlled outlet structure. This detention system was believed
to have been installed when the Fenbrook subdivision was constructed. Because the
proposed construction will disturb less than 10% of the total wetlands buffer on the
property, the application was deemed to be exempt from requiring a wetlands permit
from the Planning Board. However, all construction will be as far from the existing
watercourse and stormwater detention area as possible and erosion and sediment
control measures will be used to protect the wetlands throughout construction.
The total amount of impervious surface on site will decrease slightly from existing
conditions from 18,308 square feet (sqft) to 17,907 sqft. Stormwater from the site will
be captured and treated by catch basins and two banks of infiltrators, where
sediment, leaves and debris will be captured before overflowing to the wetlands in the
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existing stormwater detention area.
Three trees will be removed and replaced with 11 Canadian Hemlock trees, a Coral
Bark Maple, a River Birch and 6 Holly trees, a total of 19 new trees. The landscape
plans also include a variety of shrubs and perennials to be planted around the
foundation.
Based on this information, CZMC found the proposed action to be consistent with the
policies in the LWRP.
3.2. 398 Weaver Street - Residential Site Plan, Wetlands and Watercourses Permit and Tree
Removal Permit Applications for the construction of a new single family house.
Pierre Sarrazin, Architect, Shea Graham, Engineer, and Bill Kenny, Landscape
Architect and Wetlands Specialist, presented the proposal to construct a new single-
family house at 398 Weaver Street.
The proposed house will be located in an AE flood zone, adjacent to the Sheldrake
river, requiring FEMA compliance and a Wetlands and Watercourses permit from the
Planning Board. In response to comments from the planning board, the applicant has
reduced the amount of impervious surface, relocated the curb cut to a better location
on Forest Avenue, and changed the grading to minimize impact to a 24-inch London
Plane Tree.
The new house will be zoning compliant. To be FEMA-compliant, habitable space will
be constructed 4-feet above the base flood elevation. In addition, to maintain flood
storage capacity, a crawl space with flood vents will allow for flood water to enter the
crawl space during floods and will flow back out when water levels recede. The
remainder of the house will be on a slab-on-grade foundation.
The applicant's team discussed tree removal, tree protection and landscaping. They
had an arborist evaluate the trees a year ago and will have the trees evaluated again
to determine if the two Norway Maples or the Red Maple can be saved in addition to
the London Plane Tree. The engineer will modify the plans to show tree protection
fencing surrounding the critical root zone. Mr. Kenny discussed the environmental
benefit of moving the driveway as far from the Sheldrake river as possible. They
propose planting the buffer area with native shrubs and perennials and planting as
many replacement trees as will fit on the site.
Mr. Graham discussed the stormwater management system, which includes a Cultec
system and will capture and treat the runoff from the house and driveway. There will
be a decrease in the amount of impervious surface area on the property as well as a
decrease in the peak rate of runoff as compared to the current conditions.
CZMC found the proposed action to be consistent with the policies in the LWRP.
Efforts should be made to protect as many trees as possible during construction. In
addition, the foundation of the house should be designed and constructed to prevent
undermining during inevitable flood events.
3.3. Propel NY Energy - Local Consistency Review
Kathleen Marean, Katie Axt, Grant Whittington and Ed Birdie returned to CZMC to
continue the discussion of the PropelNY proposal. Part of their project involves
installing 4 submarine power transmission lines in trenches across the Long Island
Sound between New Rochelle and Hempstead Harbor in Long Island (a distance of 9
miles). Several cables managed by the NY Power Authority already cross the Long
Island Sound. PropelNY, is part of a larger, regional project to update the power
distribution system and provide more stability, capacity and redundancy to the State’s
power system. Within our LWRP jurisdiction, the cables will traverse the bottom of
the Sound for 2.6 miles. Approving agencies include but are not limited to NYSDEC,
NYSDOS and US ACOE. The NYSDOS has referred this application to CZMC for
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local consistency review.
Previously, Propel NY completed sampling of the benthos and sediments along the
proposed route to determine what species are in this area and what the physical and
chemical composition of the sediment is. They also performed an analysis to identify
any historic and archaeological resources, including shipwrecks, that may be
submerged in the project area. The study revealed that the sediment is clean and
nothing of significance was found that would cause a deviation of the route through
our jurisdiction.
At this time, Propel NY is going through the permitting process which includes
negotiating the conditions of their Article 7 certificate to be issued by the NYS public
service commission. Once they receive this certificate, they will be developing their
environmental management and construction plans.
To summarize the procedure for installation of the submarine cables, a jet plow will be
used to create a trench, fluidizing the sediment as it moves along the route. A cable
is laid to a depth of 6 feet (the cables need to be located deep enough to be protected
from damage and to provide sufficient insulation for the cables), and the sediments
settle back into the trench as the operation moves across the Long Island Sound.
Four trenches and cables will be installed in this manner, and the installation of the
cables (in our LWRP area) is expected to take approximately one day to complete.
The crossing from Long Island to New Rochelle will be completed in one to three
days.
Modeling was conducted to predict how the sediments will behave during the
installation process. The project team calculated the size of the sediment plume,
including sediment resuspension and spread, and they know the duration of time the
plume will be present. Methods for minimizing sediment resuspension were
developed. What they determined is when plough goes through, the sediment is
fluidized, the plume is narrow, localized and stays at bottom of trench. This indicates
that they can meet the water quality standards stated in Article 7 Conditions and
federal permit. The modeling will be verified in the field with a series of trenching
trials.
During installation, they can use "adaptive management" techniques to minimize
resuspension and turbidity along the route. For example, they can slow the speed of
the plough or change other parameters to reduce turbidity as needed. In addition to
oversight by NYSDEC, a third-party environmental Monitor will be required to be
present during installation and post installation monitoring will be conducted to ensure
that any impacts are mitigated.
CZMC asked about the use of lead sheathing inside the cables and has concerns
about the safety of this. The PropelNY team explained that the lead inner lining is
completely internal and will never be exposed to the environment. These cables are
different from the Y-49 cables and does not contain petroleum to provide liquid
cooling, which leaked when an anchor snagged the line. A new notification system
has been installed since that incident to alert passing ships to the presence of cables
via their navigation systems.
To help guarantee the safety and security of the cables, there will be a system
installed that will monitor the cables within the seabed. Any disruption, erosion or
change in temperature will notify the operator. For example, if an anchor should snag
the line, the system will shut down until repairs are made.
Many stakeholders have been involved with the planning process and include the
Long Island Sound Study. They are proposing to complete the installation of the
cables in the spring. CZMC suggested that the work be completed before boating
season. CZMC recommended that the local yacht clubs be notified of the project and
added to the list of stakeholders:
Larchmont Yacht Club
https://www.larchmontyc.org/
Horseshoe Harbor Yacht Club
https://www.horseshoeharbor.org/
Larchmont Shore Club
https://larchmontshoreclub.org/
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Based on the information available at this time, CZMC finds the proposed action to
be consistent with the LWRP.
4. Old Business
4.1. LWRP Update
Elizabeth Aitchison reported that Comments were finally received from NYSDOS on
the Draft of the LWRP sent to them in 2018. The comments were substantial with
regards to the format of the draft document. CZMC will continue discussion of this in
the future.
5. New Business
No New Business to discuss.
6. Next Meeting
The next CZMC meeting will be held on September 29, 2025 at 7:30pm in Conference Room
D.
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