Town of Southeast Conservation Commission
Terravest 3 - Wetlands Impacts
December 28, 2004
Thank you for providing the public with this opportunity to comment.
The Croton Watershed Clean Water Coalition, Inc. (CWCWC) particularly
appreciates this opportunity since we are both a local and a regional
organization. We have members in Southeast and all over Putnam County.
We and they are concerned with the ongoing degradation of our wetlands.
But we are also concerned with the overall impacts to the Croton
watershed, an important component of NYC's water delivery system
that supplies over half of NYS, 9 million people, with high quality
drinking water. Over 70% of Putnam County lies within this watershed.
Healthy, uncompromised wetlands play a critical role in maintaining
our high quality drinking water and in preventing its degradation.
Just as one example, wetlands are irreplaceable recharge areas that
lead to the aquifers from which we draw our well water. Wetlands
also play a critical role in protecting our reservoirs from pollution.
25% of the phosphorus entering the Middle Branch Reservoir comes
from the Town of Southeast. The proposed T-3 development is in the
Middle Branch watershed.
The Town of Southeast has recognized the importance of its wetlands
by amending its wetlands code to be among the strictest in this
For example, section 78-1B(4) states: Wetlands and water courses
conservation is a matter of concern to the entire Town and the establishment
of preservation, protection and conservation practices is essential
to the public health, safety and welfare since actions on wetlands
and water courses in one location affects persons and properties
in other location.
Section 78-2C states further: 'Controlled Area' shall include
all wetlands and the area surrounding the same based on hydrological
and slope percentage as indicated in the chart
below. The chart shows that the minimum surrounding area (or
buffer) is 100 feet. In some cases, the chart shows that the buffer
area can be as much as 200 feet.
It is important to recognize that the Town of Southeast regulates
its buffer areas to the same degree as its wetlands and watercourses.
According to the Town Code, activities within the buffers areas
are subject to the same stringent regulations.
Unfortunately, the applicant seems to be oblivious to this fact.
The wetlands buffers on T-3 are pockmarked with stormwater devices
and a variety of other structures. If the Town wetlands regulations
are to be taken seriously, these devices should be disallowed in
the buffer just as they are in the wetland itself.
There are many good reasons why wetlands buffers should be left
intact, and the Town of Southeast has fully recognized that need
in its excellent wetlands code. Here are some of those reasons.
1. Stormwater generally moves through buffers as sheet flow. This
results in the rate of flow being slowed down and the residence
time increased, allowing time for the settling of water-borne sediments
and infiltration (Broderson, 1973)1 . Stormwater devices
constructed within the buffer will channel the water in and out
of the device, thereby defeating a valuable function of the buffer.
Also, pollutants that enter wetland buffers can be removed by a
rich variety of soils, plants and bacteria. Man-made devices are
unlikely to be as effective.
2. Wetland buffers are able to moderate water level fluctuations
so that the wetland itself is not subject to large, sudden fluctuations
that could harm its vegetation and wildlife. Siting stormwater devices
in the buffers, as is being proposed by the applicant, will mean
that water that normally accesses the wetland in a gradual manner
will be detained and then released as overflow during storm events.
Such a disruption of the wetland's natural hydroperiod has been
studied and shown to be harmful to a wetland's ability to maintain
its normal functions. (Clark, 19972 , Dunne, 19783
3. Furthermore, the placing of stormwater devices in the buffers
will disrupt fish and wildlife habitat. In this respect, we are
unaware of any thorough study of the T-3 flora and fauna having
been conducted by the applicant. This critically important omission
should be remedied as soon as possible.
4. Sediment removal is an important function of wetlands buffers.
These prevent excessive sediment from loading the wetlands, and
also prevent nutrients that adsorb to the sediment particles from
reaching the wetlands. Even though a sediment basin will trap particles,
the deposit will have to be cleaned out periodically. Otherwise,
any storm event that is larger than the one for which the basin
was designed will result in sediment being washed out of the basin
and into the wetlands.
5. An exhaustive review of several hundred documents relating to
buffers by Emmons & Olivier Resources in Minnesota4 has
concluded that a minimum buffer width for effective sediment,
phosphorus and nitrate reduction is 100 feet. In all cases, a mixed
vegetative buffer consisting of grass, shrub and forest is recommended
to maximize the level of treatment.
In addition to water quality basins and detention basins, the applicant
is proposing a variety of other disturbances to the buffers. A partial
list would include access roads, a portion of a pump station, a
portion of seven housing units, retaining walls, and portions of
a baseball field. Among the water quality devices, one is 60% in
the buffer; another is 85%; a third is 90%, and a fourth is 100%
in the buffer. The total disturbance to buffers is close to 9 acres.
The residents and the boards of the Town of Southeast have designed
and approved an admirable wetlands protection code, arguably the
best in the whole NYC watershed. This application is a crucial test
as to whether this board and the citizens of this Town are willing
to uphold those regulations. If they are not willing and if they
do not demand that the applicant drastically scale back its T-3
proposal, then these regulations will be meaningless. Not only the
residents of this Town, but also the millions of people who depend
on NYC water will be the losers.
Marian H. Rose, PhD
1Broderson, J. Morris, 1973. Sizing
Buffer Strips to Maintain Water Quality. M.S. Thesis, University
of Washington, Seattle.
2Clark, J.R., 1977. Coastal Ecosystem Management: A Technical
Manual for the Conservation of Coastal Zone Resources. John
Wiley & Sons, New York, New York.
3Dunne, T.L., 1978. Water Environment in Planning,
W.H. Freeman & Co. 779 pages
4Benefits of Wetland Buffers: A Study of Functions, Values
and Size, prepared for the Minnehaha Creek Watershed District,
December 6, 2001, by Emmons & Olivier Resources, Inc., 3825
Lake Elmo Avenue N., Lake Elmo, MN 55042