A. 
Background.
(1) 
In 1972, amendments to the federal Water Pollution Control Act prohibited the discharge of pollutants into navigable waters from a point source unless authorized by a National Pollutant Discharge Elimination System (NPDES) permit. Improving water quality under this program focused on industrial wastewater and municipal sewage discharges. Once the United States Environmental Protection Agency (EPA) found an improvement in pollution control of these point source discharges, it shifted its regulatory focus to nonpoint source pollution, namely, urban stormwater runoff. A series of studies in the 1980s identified many pollutants in stormwater discharges from a variety of sources, including streets, parking lots, lawns, construction sites, maintenance facilities and other urban commercial and industrial uses. As a result, in 1990, the EPA established Phase I stormwater regulations for large communities with populations greater than 100,000 which required National/State Pollution Discharge Elimination System permits for certain municipal and industrial stormwater discharges. In 1991, Phase II of these regulations was finalized, requiring smaller communities within urbanized areas to develop plans for the control of stormwater within their jurisdictions by March 2003 with full implementation by 2008.
(2) 
The Village of Scarsdale, as an operator of a municipal separate storm sewer system (MS4), is subject to these permitting requirements as its population is greater than 10,000 and its population density is greater than 1,000 per square mile. The initial step toward providing a stormwater pollution prevention plan under Phase II is to develop and implement six minimum measures, including public education, public involvement, detection and elimination of illicit connections, construction site runoff, post-construction stormwater controls, pollution prevention and good housekeeping. This legislation is intended to address a number of these measures.
(3) 
The various provisions of this chapter are intended to regulate the impacts of construction activity in the Village on soil erosion and stormwater runoff. Stormwater runoff for single-family residences is typically managed with the installation of dry wells, detention basins, catch basins, driveway and/or curtain drains, or piping to the nearby existing municipal storm sewer system. Erosion control measures include the installation of silt fences and hay bales around properties during construction.
(4) 
This chapter differentiates large construction projects involving land disturbing activities of greater than 5,000 square feet and land disturbing activities greater than 1,500 square feet on lands located in a federally mapped floodplain, mapped New York State or local wetland or a local critical subdrainage basin by requiring comprehensive analyses and support data for such projects. Projects involving land disturbing activity of up to and less than 5,000 square feet and up to and less than 1,500 square feet on lands located in a federally mapped floodplain, mapped New York State or local wetland or a local critical subdrainage basin are required to submit more basic information. On lots 7,500 square feet or less, projects involving land disturbing activity less than 200 square feet are not subject to the requirements of this chapter. On lots greater than 7,500 square feet, projects involving land disturbing activity less than 500 square feet are not subject to the provisions of this chapter. This chapter also establishes methods for controlling the introduction of pollutants into the municipal separate storm sewer system (MS4) in order to comply with requirements of the New York State Pollution Discharge Elimination System (SPDES) permit process.
(5) 
All activities that occur as a result of Planning Board approval, including, but not limited to, subdivisions, site plans, wetlands, and special use permits, shall comply with the requirements of this chapter in addition to § A319-37 of this Code. In such cases, the Planning Board shall give consideration to the requirements of this chapter.
B. 
Findings. The New York State Department of Environmental Conservation (NYSDEC) has found that uncontrolled drainage and runoff associated with land development have a significant impact upon the health, safety and welfare of the community. Specifically:
[Amended 1-10-2023 by L.L. No. 2-2023]
(1) 
Stormwater runoff can carry pollutants into receiving water bodies, degrading water quality.
(2) 
The increase in nutrients in stormwater runoff such as phosphorus and nitrogen accelerates eutrophication of receiving waters.
(3) 
Improper design and construction of drainage facilities can increase the velocity of runoff, thereby increasing streambank erosion and sedimentation.
(4) 
Construction involving land clearing and the alteration of natural topography increases erosion and can affect drainage patterns across adjoining property boundaries.
(5) 
Siltation of water bodies resulting from increased erosion decreases their capacity to hold and transport water, interferes with navigation in downstream harbors, and harms flora and fauna.
(6) 
Sediment from soil erosion clogs catch basins, storm sewers and ditches and pollutes and silts streams, rivers, lakes, reservoirs and harbors.
(7) 
Impervious surfaces increase the volume and rate of stormwater runoff and allow less water to percolate into the soil, thereby decreasing groundwater recharge and stream base flow.
(8) 
Improperly managed stormwater runoff can increase the incidence of flooding and the level of floods which occur, endangering property and human life.
(9) 
Substantial economic losses can result from these adverse impacts on community waters.
(10) 
Many future problems can be avoided if land is developed or retrofitted with sound stormwater runoff management practices.
In order not to overburden the performance of the Village's stormwater drainage system and maintain and enhance both the immediate and long-term health, safety and general welfare of the citizens of the Village of Scarsdale, this chapter has the following objectives in accordance with certain measures identified in the SPDES Phase II regulations and the Village's Comprehensive Stormwater Management Plan.
A. 
To meet the requirements of the SPDES general permit for stormwater discharges from MS4s, Permit No. GP-02-02, as amended.
B. 
To prevent increases in the magnitude and frequency of stormwater runoff so as to prevent an increase in flood flows and the correlated hazards and costs associated with flooding to reduce siltation, prevent increases in stream temperature and stream erosion and maintain the integrity of stream channels, watercourses and waterways.
C. 
To require a certified calculation for stormwater detention and retention on existing improved properties before a proper discharge to the public storm drain system; to upgrade stormwater management practices on previously improved properties located in sensitive drainage areas (SDA) by requiring property owners to retrofit stormwater management systems for the maximum detention and retention possible for the entire site based upon calculations provided by the applicant, as required by this chapter and subject to the approval of the Village Engineer, in connection with the construction of an addition to an existing structure or other land disturbing activity so that stormwater management practices for the entire site (including retention, run-off and discharge into the public storm drain) are in full compliance with the provisions of this chapter.
D. 
To prevent decreases in groundwater recharge and stream base flow so as to maintain aquatic life, assimilative capacity, and potential water supplies.
E. 
To maintain the integrity of stream geometry so as to sustain the hydrologic functions of streams.
F. 
To regulate the discharge of pollutants to the MS4.
G. 
To prohibit illicit connections, activities and discharges to the MS4.
H. 
To control erosion and sedimentation so as to prevent its deposition in streams and other receiving water bodies.
I. 
To regulate and control the design, construction, use and maintenance of any development or other activity which disturbs or breaks the topsoil or results in the movement of earth on land situated in the Village.
J. 
To facilitate the removal of pollutants in stormwater runoff so as to perpetuate the natural biological and recreation functions of streams, water bodies and wetlands.
K. 
To secure, to the extent possible, multiple community benefits such as groundwater replenishment, open space protection and increased recreational opportunity through integrated land use-stormwater management planning.
L. 
To establish legal authority to carry out all inspections, surveillance and monitoring procedures necessary to ensure compliance with this chapter.
M. 
To promote public awareness of the hazards of the improper discharge of pollutants into the MS4.
In accordance with Articles 4 and 20 of the Village Law of the State of New York, the Village of Scarsdale has the authority to enact local laws for the purpose of the protection and enhancement of its physical environment and to promote the health, safety or general welfare of the Village. The Village may include in any such local law provisions for the appointment of any municipal officer or employee to effectuate and administer such local law.