This chapter shall be known as the "Stormwater Management and
Erosion and Sediment Control Law" of the Town of Lewisboro.
It is hereby determined that:
A.
Land development activities and associated increases in site impervious
cover often alter the hydrologic response of local watersheds and
water bodies and increase stormwater runoff rates and volumes, flooding,
stream channel erosion, and sediment transport and deposition.
B.
This stormwater runoff contributes to increased quantities of waterborne
pollutants, including siltation of aquatic habitat for fish and other
desirable species.
C.
Clearing and grading during construction tend to increase soil erosion
and add to the loss of native vegetation necessary for terrestrial
and aquatic habitats.
D.
Improper design and construction of stormwater management practices
(SMPs) can increase the velocity of stormwater runoff, thereby increasing
stream bank erosion and sedimentation.
E.
Impervious surfaces allow less water to percolate into the soil,
thereby decreasing groundwater recharge and stream baseflow.
F.
Substantial economic losses can result from these adverse impacts
on the waters of the municipality.
G.
Stormwater runoff, soil erosion and nonpoint source pollution can
be controlled and minimized through the regulation of stormwater runoff
from land development activities.
H.
The regulation of stormwater runoff discharges from land development
activities in order to control and minimize increases in stormwater
runoff rates and volumes, soil erosion, stream channel erosion, and
nonpoint source pollution associated with stormwater runoff is in
the public interest and will minimize threats to public health and
safety.
I.
Regulation of land development activities by means of performance
standards governing stormwater management and site design will produce
development compatible with the natural functions of a particular
site or an entire watershed and thereby mitigate the adverse effects
of erosion and sedimentation from development.
The purpose of this chapter is to establish minimum stormwater management requirements and controls to protect and safeguard the general health, safety, and welfare of the public residing within this jurisdiction and to address the findings of fact in § 189-2 hereof. The provisions of this chapter seek to meet those purposes by achieving the following objectives:
A.
Meet the requirements of Minimum Measures 4 and 5 of the New York
State Department of Environmental Conservation (NYSDEC) State Pollutant
Discharge Elimination System (SPDES) General Permit for Stormwater
Discharges from Municipal Separate Stormwater Sewer Systems (MS4s),
as may be amended or revised from time to time.
B.
Require land development activities to conform to the substantive requirements of the NYSDEC SPDES General Permit for Construction Activities, as may be amended or revised from time to time. Projects resulting in land disturbance of equal to or greater than 5,000 square feet may require a Town stormwater permit and coverage under the SPDES General Permit for Construction Activities, as applicable per §§ 189-5 and 189-7 of this chapter.
C.
Minimize increases in stormwater runoff from land development activities
in order to reduce flooding, siltation, increases in stream temperature,
and stream bank erosion and maintain the integrity of stream channels.
D.
Minimize increases in pollution caused by stormwater runoff from
land development activities, which would otherwise degrade local water
quality.
E.
Minimize the total annual volume of stormwater runoff which flows
from any specific site during and following development to the maximum
extent practicable.
F.
Reduce stormwater runoff rates and volumes, soil erosion and nonpoint
source pollution, wherever possible, through stormwater management
practices and to ensure that these management practices are properly
maintained and eliminate threats to public safety.
