Conservation Commission Meeting Agenda/Materials 109R and 131 Clark Lane Exhibit List (linked)

Maureen Fitzgerald
a=
From: Sigrun Nicodemus <sigrun.n.gadwa@gmail.com>
Sent: Wednesday, February 8, 2023 10:31 AM
To: Maureen Fitzgerald; Mark K. Branse; arlene sherman
Subject: Att. A -Carya Review App.Review, Part 2, Impacts Assmt: App. # C22-15; 141 Clark Lane.
Attachments: AttA. Rept 2. Excerpt, 2015 CTDEEP Fenger Brook Watershed Recommendations.pdf
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To the Waterford Conservation Commission:
The file below is Attachment A to the Carya Report2, dated 2-7-23, which I submitted to the town
electronically last night, an excerpt from the 2015 CTDEEP document, also referenced in the 1-26-23 Carya
Report. The map shows the distribution of impervious surface in the Fenger Brook watershed more clearly than
the photocopy attached to our first Report. The text excerpt uges disconnection of stormwater runoff with high
pollutant loads from the watercourse, consistent with Carya recommendations and begins with a link to the
EPA grant source for monitoring and implementing LID.
Respectfully,
Sigrun. N. Gadwa, MS
Carya Ecological Services, tc
183 Guinevere Ridge,
Cheshire, CT 06410
www.caryaecological.com
sigrun.n.gadwa@gmail.com
203 271 1949 (m) 203 537 1869
= Aen fie C-22-14
RECEMED 109R & 131 CLARK LANE
PUBLIC HEARING
r 308 2023 EXHIBIT # 33
Planning & Development
__Town of Waterford, CT C- aa
a ia oe 1
Ex 33

a" Southeast Shoreline (CT2000) Summary
Fenger Brook (CT2000-30_01)
WATERSHED DESCRIPTION
The Southeast Shoreline sub-regional basin is located
in the southeastern portion of Connecticut (Figure 1).
There are two towns located in the Fenger Brook
watershed, including the municipalities of New
London and Waterford, CT (Figure 2).
The Southeast
Shoreline sub-regional
basin includes one
segment, consisting of
the entire length of
Fenger Brook,
impaired for aquatic
life use assessed by
aquatic invertebrates.
Figure 1: Watershed This segment was
location in Connecticut assessed by
Connecticut
Department of Energy and Environmental Protection
(CT DEEP) and included in the CT 2012 303(d) list of
impaired waterbodies. Some segments in the
watershed were currently unassessed as of the writing
of this document. This does not signify that no
concerns exist with those segments, rather it is an
indication that there are not current data to evaluate
the segments as part of an assessment process. An
excerpt of the 2012 Integrated Water Quality Report is
included in Table 1.
Impaired Segment Facts
Impaired Segment:
Fenger Brook (CT2000-30_01)
Municipalities: New London and
Waterford
Impaired Segment Length (miles):
3.47
Watershed Area (square miles): 3.1
Watershed Impervious Cover: 20%
Water Quality Classification: Class A
Designated Use Impairments: Habitat
for Fish, Other Aquatic Life, and
Wildlife
Sub-regional Basin Name and Code:
Southeast Shoreline, 2000
Regional Basin: Southeast Shoreline
Major Basin: Southeast Coast
Fenger Brook is 3.47 miles in length and the entire length of the brook (CT2000-30_01) is considered
impaired. The Fenger Brook begins southeast of the Clark Lane and Chester Street intersection in
Waterford, CT. The brook continues southerly through a large forested area along the Waterford-New
London town line and passes under Route 1, adjacent to an auto body shop and several paved retail
parking lots in Waterford before entering into another forested tract. A tributary enters the brook from the
west as it passes under railroad tracks. It ends at Alewife Cove (tidal) just downstream of Niles Hill Road
on the Waterford-New London town line (Figure 2).

March 2015
Figure 4: Impervious cover (“) for the Fenger Brook Watershed
| Legend
ja) % Impervious Cover (IC)
—— Impaired Waterbody(s)
i = Impaired Drainage Area(s)
f Surface Water
Major Road
Percent Impervious Cover (IC) within Fenger Brook Watershed with
Impairment to Habitat for Fish, Other Aquatic Life and Wildlife Created: CT DEEP, July 2012
Southeast Shoreline (CT2000) Summary
Page 6 of 16

March 2015
RECOMMENDED NEXT STEPS
CT DEEP can assist with reducing the effect of IC by providing technical and financial assistance to the
watershed towns and local citizen watershed advocacy groups, effectively administering stormwater
permitting programs, and monitoring aquatic life in the surface waters. Under Section 319 of the Clean
Water Act (§319 C.W.A.), the U.S. Environmental Protection Agency awards a grant annually to the CT
DEEP to fund eligible projects that control and/or abate nonpoint source pollution through a competitive
bid process. More information on grant programs can be found on the Department’s website
(http://www.ct.gov/deep/cwp/view.asp?a=2719&q=325594&deepNav_GID=1654).
1) Reduce the effect of impervious cover in the Fenger Brook watershed through the
implementation of Best Management Practices (BMPs) to control stormwater runoff.
As noted previously, 38% of the Southeast Shoreline sub-regional basin is considered developed and the
municipalities within the watershed are MS4 communities regulated by the MS4 program. The amount of
impervious cover in the Fenger Brook watershed is 20%.
Reducing the effect of IC in the watershed is an important step to decrease the impacts of stormwater
runoff on water quality. For new development, LID principles (http://www.ct.gov/deep/watershed)
should be utilized to retain and infiltrate stormwater runoff and/or reduce the amount of runoff from IC. In
developed areas, IC should be disconnected from surface waterbodies, where practicable. Disconnection
of impervious surface runoff should be pursued to the degree feasible when reconstruction of a site and/
or its infrastructure occurs. For example, stormwater outfalls could be redirected to vegetated areas to
encourage natural filtration before reaching nearby waterbodies.
An excellent guide on how to implement a reduction in IC is found in Appendix 3 of the core document
and on the web (http://clear.uconn.edu/projects/tmdl/). A retrofit assessment of the watershed would
identify areas where BMPs such as gravel wetlands, porous pavement, and vegetated buffers could be
implemented to most effectively treat stormwater runoff throughout the watershed. This type of
assessment could be linked to existing Municipal Comprehensive or Master Plans, MS4-required SMPs or
watershed management plans.
2) Prevent future degradation of Fenger Brook and its tributaries through the development and/or
strengthening of local stormwater control ordinances.
As the amount of IC in the Fenger Brook watershed is greater than 12%, the adoption of a municipal
stormwater ordinance can be an effective method to protect the water quality in the watershed.
Stormwater ordinances can focus on different aspects of stormwater management to reduce the quantity
and quality of the stormwater that reaches nearby waterbodies. Effective stormwater ordinances prohibit
non-stormwater discharges (to the storm sewer or surface waterbodies) such as sanitary sewage and
wastewater discharges, require the use of adequate controls to prevent erosion and sedimentation, and
specify enforcement mechanisms to address non-compliance. In addition to local ordinances, the
establishment of a stormwater utility (i.e. a user fee) can be an effective way to address the impact of
stormwater runoff from impervious surfaces while also providing the fiscal means of addressing
municipal stormwater infrastructure needs. Utility fees are usually based on the size of effective
impervious area and so, strongly encourage the reduction of impervious area.
3) Protect existing buffers along the riparian corridor and other conservation lands throughout the
watershed.
Southeast Shoreline (CT2000) Summary
Page 12 of 16

March 2015
Riparian buffers and other natural landscapes can protect the water quality of waterbodies within a
watershed. The riparian buffer zone is the area of land located immediately adjacent to streams, lakes, or
other surface waters. The incorporation of buffer requirements in the municipal land use approval process
will help protect these areas near Fenger Brook from the effect of IC, and these streams can be protected
from further degradation due to stormwater runoff.
Riparian zones differ from the uplands because of high levels of soil moisture, frequent flooding, and the
unique assemblage of plant and animal communities found there. These areas can reduce the impacts of
IC by filtering pollutants and slowing runoff. Through the interaction of their unique soils, hydrology, and
vegetation, natural riparian areas influence water quality as contaminants are taken up into plant tissues,
adsorbed onto soil particles, or modified by soil organisms. They also can protect the shoreline from
erosion, aid in flood control, provide habitat for wildlife, shade waters for fish, and offer scenic value.
Any change to the natural riparian buffer zone can reduce the effectiveness of the natural buffer and has
the potential to contribute to water quality impairment (USEPA, 201 1a).
The riparian zones for the impaired segments in the Fenger Brook Watershed are characterized by a mix
of land uses including developed, forested, and consisting of wetlands (Figure 6). Development is
focused along the Route 1 corridor near the middle reaches of the brook as well as near the mouth of the
brook as it empties into the tidal Alewife Cove. A tributary entering Fenger Brook from the west has a
concentrated developed area near its headwaters and passes underneath Rope Ferry Road and between a
residential development and Waterford High School. The IC within all developed areas is typically
transporting stormwater via structured drainage systems that often discharge within the riparian areas or
directly to surface waters.
Southeast Shoreline (CT2000) Summary
Page 13 of 16