HomeMy WebLinkAboutStorm Water Runoff Detrimental Effects to Surface Water Quality 1994Program to Mitigate the Detrimental
Effects of Direct Discharge of
Stormwater Runoff to Surface
Water Quality
July 25, 1994
Town of Southolld
TOWN OF SOUTHOLD
PROPOSAL DESCRIPTION
$OUTHOLD TOWN'S PROGRAM TO MITIGATE THE DETRIMENTAL EFFECTS OF DIRECT
DISCHARGE OF STORMWATER RUNOFF TO SURFACE WATER QUALITY.
Description of Project Location and Project Rationale:
The North Fork is a narrow peninsula about twenty-five miles long. Due to its
elongated shape, there are just two main east-west roads within the Town, State Route
25 and County Route 48. Of the two highways, SR 25 not only handles the bulk of the
automobile traffic within the Town; it is the sole east-west link between Greenport
Village and Odent Point.
There are numerous locations where stormwater runoff from SR 25 is deposited directly
into the Town's saltwater wetlands, creeks and bays, as well as its freshwater wetlands
and ponds. Largely unfiltered, this discharge is considered a significant source of total
and fecal coliform bacteria to the Town's surface waters. High coliform counts are the
primary cause for the periodic and sometimes chronic closing of shellfish beds within
the Town's creeks. Further, the direct discharge of storm or melt water from salted
highways into freshwater ponds and wetlands may contribute to significant and
detrimental salinity changes to these surface waters.
Our concern is not the quantity of the runoff, but rather its quality. The introduction of
freshwater via groundwater seepage and stormwater drainage is necessary to the
proper and natural functioning of an estuarine ecosystem. However, pollutants in the
water can have detrimental effects on estuarine flora and fauna.
The Town has been addressing this problem since 1986, when an informal survey was
made of the entire shorefront in order to locate all stormwater drainage pipes entering
surface waters. Since then, two stormwater filtration beds have been constructed at the
heads of creeks. The specially designed beds use phragmites and other wetlands
vegetation to filter particulate matter from the stormwater before it enters surface
waters. The locations of these projects are noted on the attached map.
Of particular note is the Hobart Road project. The Hobart Road reed bed filters all the
drainage entering the head of Town Creek in the hamlet of Southold. Funded jointly by
the US Environmental Protection Agency and the Town, it was designed by the Town
engineering and highway staffs with assistance from the Cornell University
Cooperative Extension's Marine Science Division. In 1992 this reed bed facility was
built by the Town's Highway department using private property over which the Town
had negotiated an easement. Almost all of the stormwater runoff entering this site is
from SR 25.
The Town undertook this experimental project in order to bring back one of its most
productive starter creeks for this shellfish. In 1990, Town Creek was closed to
shellfishing by the NYSDEC. An investigation revealed that the Hobart Road drainage
area at the head of Town creek was a significant source of contamination. As a direct
result of the installation of the reed bed, the creek is now open seasonally, during the
winter months.
Presently, the Town is taking part in the development of the Peconic Estuary
management program through its participation in the various committees responsible for
its design and implementation. One of the many objectives of this program is to
eliminate the introduction of contaminants by the direct discharge of stormwater into the
creeks and bays of the estuary.
Later this year, the Town will be completing its Local Waterfront Revitalization Program
(LWRP). The primary focus of the LWRP is the conservation and protection of the
Town's coastal waters on which two of the Town's three major industries, fisheries and
tourism/recreation, depend. By way of illustration, the Town's seed clam and oyster
program's average annual investment of $16,000 is estimated to yield a wholesale
value of 1.4 million dollars per year.
The Town intends for this proposal to supplement its own efforts. Our first priority is to
address the ten sites set forth in previous correspondence to Jack Catanzaro, a copy of
which follows.
Description of ProJect Implementation
In order to implement this project, the Town proposes specific design options for each
of the ten sites noted on its Priority List of June 9th. The subsequent pages outline
each project's location, a description of the proposed construction and a preliminary
cost estimate.
Description of Project Cost
A summary of the preliminary cost estimates is provided below. More detailed cost
estimate will be available after the engineering drawings are completed.
Description of Project Maintanance
It is expected that maintenance on State property would be the responsibility of the
NYSDOT. However, if Town property or easements over private property are obtained
by the Town for eventual connection with State drainage facilities, the Town would
assume responsiblity for that which lies within its jurisdiction.
Description of Project Goals and Benefits
Implementation of this project as proposed will achieve the following goals:
1. To improve the quality of our marine and fresh surface waters by filtering
stormwater runoff before it enters those bodies of water.
2. To utilize or mimic natural systems and landforms (as opposed to hard
structures) in the design of stormwater retention and filtration facilities.
Achieving these goals will result in the following benefits:
1. The water quality of the receiving waters adjacent to the discharge points on the
priority list will be improved by the reduction in the overall level of
particulate matter and pollutants.
2. The stormwater retention and mitigation facilities will present an unobtrusive,
natural-looking addition to the landscape.
3. The Townspeople (whether baymen or recreational clammers) will benefit from a
reduction of bed closings.
4. Improved water quality in the Town's creeks is anticipated to enhance the
estuary's functioning as a shellfish and fishery resource.
Implementation of this Proposal:
This first-stage proposal is anticipated to take two years to design and complete
construction. However, we recognize that changing or unexpected field conditions may
delay this projected timetable.
STORMWATER MITIGATION CONCERNS OF THE NORTH FORK
The Project Rationale provides a bdef discussion of the extent of the work the Town
is preparing to undertake to ensure and improve the quality of its surface waters. A
more detailed treatment of the extent to which the Town may be expanding its
activities in this area is set forth here.
First, the Supervisor has directed the Board of Trustees, the Community
Development Department, the Planning Department, the Highway Department, the
Conservation Advisory Council, and the Transportation Advisory Committee to
coordinate planning efforts on stormwater runoff mitigation.
Second, in addition, the Board of Trustees, which owns the Town's underwater and
wet lands, has a standing Shellfish Advisory Committee which works to ensure the
protection and enhancement of the Town's shellfishery. To illustrate the potential
economic value of that fishery alone, the Town's average annual investment of
$16,000 per year in its clam and oyster seed program is estimated to generate a
wholesale value of $1,400,000 per year. The Trustees and the Shellfish Committee
are are updating and refining the 1986 list of runoff problem sites throughout the
Town. This Committee also will be creating a prioritized listing of stormwater
drainage sites that should be addressed first. This is a substantial undertaking for
the Town's shoreline length (including its creekfront) is estimated to be more than
200 miles. There are more than one hundred drainage sites other than those on
State Route 25 that are likely to require some remediation.
Third, the Town Supervisor has met with the Commissioner of the Suffolk County
Department of Public Works about the discharge sites that originate from County
roads. The County Commissioner has committed his department to a review of those
problem sites.
Fourth, in the June 1994 Recommendations of the Town's Stewardship Task Force,
the importance of the Town's surface waters to its economy and quality of life are
explained. The relevant sections of that report are included here for convenient
reference.
TOWN OF SOUTHOLD
STORMWATER RUN-OFF MITIGATION PROGRAM
NEW YORK STATE ROUTE 25
PROJECT DESCRIPTIONS & PROPOSED CONSTRUCTION
JULY 8, 1994
SITE # IA.
HALLOCKS BAY: Route 25, 1938' East of Platt Road
Existing site conditions:
An existing recharge basin is located on north side of Rte.25.
There is an existing road adjacent to the east side of the
basin. This road contributes a large amount of run-off and
silt to the problem at this location. The basin also has an
overflow culvert that crosses under Rte.25 and spills into a
drainage ditch that winds its way back to Narrow River &
Hallocks bay.
Easements and/or property to be acquired:
Owners of the private property need to be contacted for
permission to construct a drainage system that would trap the
silt and divert the runoff before it enters the Main road.
This run-off should be diverted directly into the recharge
basin by installing a new manhole and headwall.
Proposed Construction:
The existing private road end will require a system of Catch
Basins and Manholes to allow the run-off direct access to the
Recharge Basin before it enters the main road. The existing
site condition allows the runoff to spill out into the main
road carrying with it large amounts of silt and topsoil. This
road end will also require concrete curbs and asphalt paving
to prevent the undermining of the proposed structures. The
recharge basin will require dredging to remove any silt build
up from previous farm runoff. The basin should be backfilled
with clean sand & gravel to an elevation of 6" min. above the
water table.
The drainage ditch or spillway on the south side of Rte.25
will first require clearing and grubbing to allow access fore
additional work. A system of dikes or weirs should be
constructed down the length of the ditch at 100' intervals to
allow for a uniform and controlled flow of surface water run-
off. The first stage of the trench should be backfilled with
a compacted granular material to act as a bio-filter.
Cornell Cooperative Extension should be contacted for there
expertise associated with the types and quantities of
vegetation that could be planted within the remaining ditch
sections to provide maximum filtration.
TOWN OF SOUTHOLD
STORMWATER RUN-OFF MITIGATION PROGRA24
NEW YORK STATE ROUTE 25
PROJECT DESCRIPTIONS & PROPOSED CONSTRUCTION
JULY 8, 1994
SITE # lB. HALLOCKS BAY: Route 25, 800' EAST OF NARROW RIVER
ROAD.
Existing site conditions:
There is an existing culvert below the road at this location.
This culvert is also located at the low point of the state
road. Under a current ~oject, this culvert is being
repaired. To clean up the Road run off it would be necessary
to establish a reed bed or bio-filter on the south side of the.
road.
Easements and/or property to be acquired:
The bio-filter will need to be constructed on N.Y.State D.E.C.
owned wetlands. An easement to or the purchase of property
will be necessary.
Proposed Construction:
The project consists of construction of a storm water run off
bio-filter on the south side of Rte.25 The storm wa[er runoff
from the road will enter the bio-filter immediately adjacent
to the south side of the existing culvert under the road. The
first portion of the filter should be a sediment collection or
recharge basin area that will overflow into a reed bed of
aquatic plantings that will absorb the harmful nutrients in
the run off. The entire filter area should encompass about
0.5 acres. A system of weirs and sluiceway should be used to
control erosion.
TOWN OF SOUTHOLD
STORMWATER RUN-OFF MITIGATION PROGRAM
NEW YORK STATE ROUTE 25
PROJECT DESCRIPTIONS & PROPOSED CONSTRUCTION
JULY 8, 1994
SITE # 2.
RICHMOND CREEK: Route 25, 800' East of Indian Neck
Road.
Existing site conditions:
A system of catch basins extend both to the east & west of
this location for a considerable distance. A drainage
easement exists across the open land or buffer area of an
approved subdivision. This easement extends in a southerly
direction for about 500' until it reaches the head of Richmond
Creek. This easement contains a direct outfall pipe that
dumps into the creek. The easement was paved with asphalt and
has since totally overgrown with vegetation.
Easements and/or property to be acquired:
None required.
Proposed Construction:
The existing Right-of-Way should be cleared and grubbed for
its entire length. A system of 10' diameter x 4' deep
leaching rings with cast iron manhole covers should be
installed at 20' intervals to provide for sediment containment
and recharge of the runoff. An outfall overflow pipe should
extend to a headwall that would spill into a reed bed or bio-
filter constructed within an excavated trench that can be
backfilled with clean granular material that would act as a
filter for the remaining run 0ff.
TOWN OF SOUTHOLD
STORMWATER RUN-OFF MITIGATION PROGRAM
NEW YORK STATE ROUTE 25
PROJECT DESCRIPTIONS & PROPOSED CONSTRUCTION
JULY 8, 1994
SITE # 3.
JOCKEY CREEK: Rte.25 100' East of intersection with
Main Bayview and Lower Road.
Existing site conditions:
A direct out fall pipe enters directly into the head waters of
Jockey Creek. Rte.25 slopes to this point from about 3,000
feet in either direction. The area around and leading up to
the site is very congested. This is proving to be difficult
when it comes to considering a conventional approach to.
treating the run off.
Easements and/or property to be acquired:
Some properties near the run off site are still vacant. It
might be possible to purchase or gain easements to these
particular pieces of land. These adjacent pieces of land will
need to be verified prior to formulating design parameters.
Proposed Construction:
Unknown at this time due to the extent & complexity of the
problem and the lack of information about existing drainage
facilities underneath State Route 25.
Technical assistance from N.Y.S.D.O.T. will be needed before
solutions can be finalized.
PRELIMINARY CONSTRUCTION COST ESTIMATE
Theoretical Budget $ 400,000.00 +/-
TOWN OF SOUTHOLD
STORMWATER RUN-OFF MITIGATION PROGRAM
NEW YORK STATE ROUTE 25
PROJECT DESCRIPTIONS & PROPOSED CONSTRUCTION
JULY 8, 1994
SITE # 4.
JAMES CREEK: Rte.25 & Bay Avenue.
Existing site conditions:
A direct out fall pipe enters directly into the head waters of
James Creek. Rte.25 slopes to this point from about 3,000
feet in either direction. The area around and leading up to
the site is very congested. This is proving to be difficult
when it comes to considering a conventional approach to
treating the run off. The area around the site is very low.
Test holes will be required to verlfy if standard drainage
rings along the shoulder of the road can be utilized.
Easements and/or property to be acquired:
It does not appear that any of the properties near the runoff
site are vacant. It might not be possible to purchase or gain
easements to a particular piece of land to solve the runoff
problem.
Proposed Construction:
Unknown at this time due to the extent & complexity of the
problem and the lack of information about existing drainage
facilities underneath State Route 25.
Technical assistance from N.Y.S.D.O.T. will be needed before
solutions can be finalized.
PRELIMINARY CONSTRUCTION COST ESTIMATE
Theoretical Budget $ 400,000.00 +/-