The terms used in this article or in documents prepared or reviewed under this article shall have the meanings as set forth in this section. Certain definitions set forth herein are taken from the Design Manual and/or Erosion Control Manual and are technical in nature and intended for use by engineers and other professionals who are engaged in the design of stormwater facilities.
ADDITIONAny work on an existing structure that changes the external dimensions of such structure.
ADJOINING PROPERTYAny property facing a work site across any right-of-way, street or highway shall be deemed adjoining property, as well as any property contiguous on any side.
ALTER HYDROLOGY FROM PRE- TO POST- DEVELOPMENT CONDITIONSThe post-development peak flow rate(s) have increased by more than 5% of the pre-developed condition for the NOAA Atlas 14 PFDS-derived precipitation frequency estimates for the site location of interest (e.g., 25 years and 100 years). Hydrologic soil group designations used for design shall be established via site-specific subsurface investigation performed in conformance with Appendix D of the NYS Stormwater Management Design Manual. NRCS Web Soil Survey data may be cited for background information but shall not be used to size structural practices.
ALTERNATIVE SIZING CRITERIAThe sizing criteria that can be achieved in redevelopment projects through a variety of approaches as outlined in Chapter
9 of the New York State Stormwater Management Design Manual.
Stormwater management practices that are outlined in this article for potential application in redevelopment scenarios and are designed and implemented in accordance with the recommendations in this article.
APPEALA request for a review of the local administrator's interpretation of any provision of this article or a request for a variance.
APPLICANTA property owner or agent of a property owner who has filed an application for a land development activity.
BEST MANAGEMENT PRACTICES (BMPs)Schedule of activities, prohibitions, general housekeeping practices, pollution prevention and educational practices, maintenance procedures and other practices to prevent or reduce the discharge of other pollutants directly or indirectly to stormwater, receiving waters or stormwater conveyance systems; procedures and methods pertaining to construction activities which are intended to minimize water pollution, retain valuable topsoil and prevent erosion and sedimentation and include, but are not limited to, those practices contained in the most recent versions of the New York State Stormwater Management Design Manual and the New York Standards and Specifications for Erosion and Sediment Control. BMPs are to be complied with on all plans submitted with an application for a stormwater management and erosion and sediment control permit regardless of the size of the land disturbance.
BEST MANAGEMENT PRACTICES MANUALSThe most recent editions of a series of manuals published by the State of New York, consisting of various volumes on best management practices for certain described activities and, specifically, the publications titled "New York State Stormwater Management Design Manual" dated July 31, 2024, as may be amended or revised (the "Design Manual"), and the "New York Standards and Specifications for Erosion and Sediment Control" dated November 2016, or as may be amended or revised (the "Erosion Control Manual").
BUILDINGAny structure, either temporary or permanent, having walls and a roof, designed for the shelter of any person, animal, or property, and occupying more than 100 square feet of area.
CHANNELA natural or artificial watercourse with a definite bed and banks that conducts continuously or periodically flowing water.
CLEAN WATER ACTThe Clean Water Act of 1977 (33 U.S.C. §
1251 et seq.), and any subsequent amendments thereto.
Any activity that removes the vegetative surface cover.
CONNECTION PERMITAn authorization for the connection as well as the discharge permitted under this article, as well as a discharge permitted under an SPDES permit, waiver, or waste discharge order issued by the NYSDEC. This permit is subject to special terms and conditions set by the Village or its designated consultant. This permit expires on or before the expiration of the NYSDEC SPDES permit, waiver or order or upon changes of ownership or use of the property.
CONSTRUCTION ACTIVITYIncludes activities subject to NYSDEC permits and SPDES permits or activities covered by erosion and sediment control and pollution prevention laws. These activities include construction projects resulting in land disturbance of one acre or more. Such activities include but are not limited to clearing and grubbing, grading, excavating, and demolition.
DEPARTMENTThe New York State Department of Environmental Conservation (NYSDEC).
DESIGN MANUALThe New York State Department of Environmental Conservation (NYSDEC) Stormwater Management Design Manual, most recent version, including applicable updates, that serves as the official guide for stormwater management principles, methods and practices.
DETENTIONA practice to store stormwater runoff by collection as a temporary pool of water and provide for its gradual (attenuated) release; a practice which is used to control peak discharge rates and which provides gravity settling of pollutants.
DEVELOPERA person who undertakes land development activities.
DEVELOPMENTTo make a site or area available for use by physical alteration. Development includes but is not limited to providing access to a site, the clearing of vegetation, grading, earth moving, providing utilities and other services such as parking facilities, stormwater management and erosion control systems, altering landforms or construction of a structure on the land.
DISCHARGERAny person or entity, permitted by law or not, that is releasing, emptying, conveying or unloading fluids and materials, including but not limited to hazardous materials and illicit discharges, as defined by this article, into the municipal storm sewer system.
EMERGENCY RESPONSE AGENCYAny governmental agencies, including but not limited to the New York State Department of Environmental Conservation, the Westchester County Department of Health and the Village of Mamaroneck Police and Fire and other appropriate Village departments.
EROSIONThe removal of soil particles by the action of water, wind, ice or other meteorological or geological agents.
EROSION CONTROL MANUALThe most recent version of the New York Standards and Specifications for Erosion and Sediment Control Manual, commonly known as the "Blue Book."
EXISTING GRADEThe vertical location of the existing ground surface prior to excavation or filling.
FINAL GRADEThe vertical location of the ground or pavement surface after the grading work is completed in accordance with the site development plan.
FLOODPLAINFor a given flood event, that area of land temporarily covered by water which adjoins a watercourse. Land within the floodplain is property within the 100-year flood boundary as shown on Flood Insurance Rate Map (FIRM) dated September 28, 2007, for the Village of Mamaroneck, as issued by the Federal Emergency Management Agency (FEMA), as amended from time to time.
FOREBAYAn extra storage area or treatment area, such as a sediment pond or created wetland, near an inlet of a stormwater management facility to trap incoming sediments or take up nutrients before they reach a retention or extended detention pond.
GRADINGExcavation or fill or any combination thereof and shall include the conditions resulting from any excavation or fill.
GRAVELPoorly/open graded angular crushed stone used for stormwater storage and/or infiltration practices, including: A) aggregate consisting of mixed sizes of one-fourth-inch to three-inch particles which normally occur in or near old streambeds and have been worn smooth by the action of water; and B) a soil having particle sizes, according to the Unified Soil Classification System, ranging from the No. 4 sieve size angular in shape as produced by mechanical crushing. NYSDOT road subbase material shall be considered impervious. The Village Engineer shall provide technical guidance related to hydrologic modeling (e.g., curve numbers) for gravel surfaces, trenches, beds, reservoirs, etc. This includes subsurface gravel installed beneath pervious pavers, porous pavement and other similar green infrastructure and standard stormwater management practices.
GREEN INFRASTRUCTUREIn the context of stormwater management, the term "green infrastructure" includes a wide array of practices at multiple scales to manage and treat stormwater, maintain and restore natural hydrology and ecological function by infiltration, evapotranspiration, capture and reuse of stormwater, and establishment of natural vegetative features. On a regional scale, green infrastructure is the preservation and restoration of natural landscape features, such as forests, floodplains and wetlands, coupled with policies such as infill and redevelopment that reduce overall imperviousness in a watershed or ecoregion. On the local scale green infrastructure consists of site- and neighborhood-specific practices and runoff reduction techniques. Such practices essentially result in runoff reduction and/or establishment of habitat areas with significant utilization of soils, vegetation, and engineered media rather than traditional hardscape collection, conveyance and storage structures. Some examples include green roofs, trees and tree boxes, pervious pavement, rain gardens, vegetated swales, planters, reforestation, and protection and enhancement of riparian buffers and floodplains. (See current Design Manual for reference.)
HAZARDOUS MATERIALSAny material, including any substance, waste, or combination thereof, which, because of its quantity, concentration, or physical, chemical, or infectious characteristics, may cause, or significantly contribute to, a substantial present or potential hazard to human health, safety, property, or the environment when improperly treated, stored, transported, disposed of or otherwise managed.
ILLEGAL CONNECTIONAn illegal connection is defined as any of the following:
(1) Any drain or conveyance, whether on the surface or subsurface, which allows an illicit discharge to enter the storm sewer system, including, but not limited to, any conveyances which allow any nonstormwater discharge, including treated or untreated sewage, process wastewater and wash water, to enter the storm sewer system;
Any connections to the storm sewer system from indoor drains and sinks, regardless of whether said drain or connection had been previously allowed, permitted, or approved by an authorized enforcement agency;
Any drain or conveyance connected from a commercial or industrial land use to the storm sewer system which has not been documented in plans, maps, or equivalent records and approved by an authorized enforcement agency.
ILLICIT DISCHARGEAny discharge through an unauthorized connection, including a direct or indirect nonstormwater discharge to the storm sewer system, except as exempted in this article.
IMPAIRED WATER BODIESWater bodies impaired by pollutants related to construction activity, including turbidity, silt/sediment, and nutrients (e.g., nitrogen, phosphorus). The list is provided in Appendix D of the SPDES General Permit for Construction Activities (GP 0-25-001) and is a subset of "The Final New York State 2018 Section 303(d) List of Impaired Waters Requiring a TMDL" dated June 2020.
IMPERMEABLE SURFACEThose surfaces in the urban landscape that cannot effectively infiltrate rainfall consisting of building rooftops, pavement, sidewalks, driveways. Steep slopes and compact soils are not typically included as impervious cover. This definition includes well/close graded material meeting the specifications for New York State Department of Transportation (NYSDOT) road subbase material (formerly known as "Item 4"). NYSDOT road subbase material shall be considered impervious. Decks constructed above the ground surface that allow 100% pass-through of stormwater to the ground surface below said decks shall be considered to be permeable.
IMPERVIOUSSurfaces such as, but not limited to, pavement, walks, patios, terraces, decks, rooftops, gravel surfaces, NYSDOT road subbase material (formerly known as "Item 4") and other well/close graded material, tennis courts and swimming pools, which prevent or inhibit the percolation of water into the soil. Porous/pervious hardscape installed to the Design Manual standards shall be considered pervious for WQv sizing; however, in Hydrologic Soil Group D soils or where seasonal high groundwater is within two feet of the subbase, such systems shall be considered hydraulically limited and modeled as partially or fully impervious for peak flow calculations unless infiltration feasibility and storage are demonstrated by testing.
INDUSTRIAL STORMWATER PERMITA state pollutant discharge elimination system permit issued to a commercial industry or group of industries, which regulates the pollutant levels associated with industrial stormwater discharges or specifies on-site pollution control strategies.
INFILTRATIONA practice designed to promote the recharge of groundwater by containment and concentration of stormwater into porous soils.
JURISDICTIONAL WETLANDAn area that is inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support a prevalence of vegetation typically adapted for life in saturated soil conditions, commonly known as hydrophytic vegetation.
LAND DEVELOPMENT ACTIVITYAny construction activity, including clearing, grading, excavating, soil disturbance or placement of fill, that could potentially result in soil erosion and/or any change in movement of stormwater on the site.
LAND-DISTURBING ACTIVITYAny change to land which may result in soil erosion from water or wind and the movement of soil into water or onto lands, alteration of a drainage system, or increased runoff of waters, including, but not limited to, clearing, grading, excavating, transporting and filling of land.
LANDOWNERThe legal or beneficial owner of land, including those holding the right to purchase or lease the land, or any other person holding proprietary rights in the land.
MAINTENANCE AGREEMENTA legally recorded document that acts as a property deed restriction, and which provides for long-term maintenance of stormwater management practices.
MUNICIPAL PERMITAny permit or license issued by the Village of Mamaroneck, including, but not limited to, building, grading, demolition, clearing, topsoil removal, excavation, tree removal, and special use permits, and subdivision and site plan approval.
MUNICIPAL SEPARATE STORM SEWER SYSTEM (MS4)A conveyance or system of conveyances and retention and infiltration facilities (including roads with drainage systems, curbs and gutters on municipal streets, manholes, catch basins, ditches, man-made channels, storm drains, stormwater basins, drainage reserve areas, dry wells and/or any other component of a stormwater system) that is owned and/or operated by the Village or another municipal entity, designed and/or used for collecting, conveying, storing, infiltrating, or managing stormwater, which is not a combined sewer and which is not part of a publicly owned treatment works as defined at 40 CFR
122.2.
Any construction or disturbance of a parcel of land that is currently undisturbed or unaltered by human activities and in a natural state.
NONPOINT-SOURCE POLLUTIONPollution from any source other than from any discernible, confined, and discrete conveyances, and shall include, but not be limited to, pollutants from agricultural, silvicultural, mining, construction, subsurface disposal and urban runoff sources.
OUTFALLThe terminus of a storm drain where the contents are released.
OUTFLOW CONTROL STRUCTUREA permanent structure placed at the discharge point of a stormwater conveyance system designed to control discharge of stormwater from the system.
PEAK DISCHARGE RATEThe maximum instantaneous rate of flow during a storm, usually in reference to the specific NOAA Atlas 14 PFDS-derived precipitation frequency estimates for the site location event. Hydrologic soil group designations used for design shall be based on site-specific testing per Appendix D of the NYS Stormwater Management Design Manual; NRCS Web Soil Survey may be cited for background only and shall not be used to size structural practices. For preliminary screening, unrated areas may assume Group D parameters until testing is completed.
PEAK FLOWThe maximum rate of flow of water at a given point and time resulting from a storm event.
PEAK FLOW ATTENUATIONThe reduction of the peak discharge of stormwater runoff by detention and gradual release of that storage.
PERSONAny corporation, partnership, association, trust, estate, or any other entity recognized by law and acting as either the owner or the owner's agent, including state and local governments and agencies, authorities, or other political subdivisions thereof, and one or more individuals.
PERVIOUS/POROUS HARDSCAPEPervious systems (porous asphalt, pervious concrete, permeable interlocking concrete pavers) shall be treated as pervious for water quality (WQv) when designed, constructed, and maintained in accordance with the NYS Stormwater Management Design Manual; for water quantity (peak flow/volume) they may be credited only to the extent supported by site-specific infiltration testing and storage design pursuant to Appendix D of the Design Manual.
PHASINGClearing a parcel of land in distinct pieces or parts, with the stabilization of each piece completed before the clearing of the next.
POLLUTANTAnything that causes or contributes to pollution. Pollutants that may cause or might reasonably be expected to cause pollution of the waters within New York State may include, but are not limited to, dredged soil, filter backwash, solid waste, incinerator residue, treated or untreated sewage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, hazardous materials, heat, wrecked or discarded equipment, rock, sand, industrial and agricultural waste, ballast discharged into water, paints, varnishes and solvents, oil and other automotive fluids, nonhazardous liquid, yard waste, refuse, rubbish, garbage, litter, or other discarded or abandoned objects and accumulations so that same may cause or contribute to pollution, floatables, pesticides, herbicides, particulate metals, animal waste, waste and residue resulting from constructing a building or structure and noxious or offensive matter of any kind.
PREMISESAny building, lot, parcel of land or portion of land, whether improved or unimproved, including adjacent sidewalks and parking areas wholly within the property boundaries of a particular site.
PRIMARY STRUCTURE(S)All structures on a premises used for the primary use of said premises, including all garages, workshops, basements, pools, cabanas, but excluding sheds used exclusively for incidental storage.
PROJECTAny land development activity and/or other construction associated with such land development
RECHARGEThe replenishment of underground water reserves through infiltration.
REDEVELOPMENTReconstruction or modification to any existing, previously developed land such as residential, commercial, industrial, institutional or road/highway, which involves soil disturbance. Redevelopment is distinguished from development or new development in that new development refers to construction on land where there had not been previous construction. Redevelopment specifically applies to constructed areas with impervious surface.
REDEVELOPMENT PROJECTA project that undergoes redevelopment. The project area can be entirely under redevelopment or the project area can be a combination of redevelopment and new development.
RETENTIONA practice designed to store stormwater runoff by collection as a permanent pool or tank of water without release except by means of evaporation, infiltration, or attenuated release when runoff volume exceeds the permanent storage capacity of the permanent pool or tank.
SENSITIVE AREASCold-water fisheries, shellfish beds, swimming beaches, groundwater recharge areas, water supply reservoirs, and habitats for threatened, endangered or special-concern species.
STABILIZATIONThe use of practices that prevent exposed soil from eroding.
STANDARD PRACTICEA standard stormwater management practice that appears in Chapter
3 or
6 of the New York State Department of Environmental Conservation Stormwater Management Design Manual, sized in accordance with Chapter 4 or 10, and designed in accordance with Chapter
6 or 10 of the Design Manual.
The first land-disturbing activity associated with a development, including land preparation such as clearing, grading and filling; installation of utilities, streets and walkways; excavation for basements, footings, piers, or foundations; erection of temporary forms; and the installation of temporary or accessory buildings such as construction sheds or trailers and garages.
STOP-WORK ORDERAn order issued which requires that all construction activity on a site be stopped.
STORMWATERAny surface flow, runoff, and/or subsurface drainage consisting entirely of water from any form of natural precipitation and resulting from such precipitation.
STORMWATER APPURTENANCESStructures such as dry wells, catch basins, piping, storm drains and detention/retention basins designed to control and manage the flow of stormwater.
STORMWATER CONVEYANCE SYSTEM (DRAINAGE SYSTEM)Publicly owned facilities on public land or privately owned facilities on private land by which stormwater is collected and/or conveyed, including, but not limited to, any roads with drainage systems, municipal streets, gutters, curbs, inlets, piped storm drains, pumping facilities, retention and detention basins, natural and human-made or altered drainage channels, reservoirs, and other stormwater appurtenances to control and manage the flow of stormwater.
STORMWATER HOTSPOTA land use or activity that generates higher concentrations of hydrocarbons, trace metals or toxicants than are found in typical stormwater runoff, based on monitoring studies.
STORMWATER MANAGEMENTThe use of structural or nonstructural practices that are designed to reduce stormwater runoff and mitigate its adverse impacts on property, natural resources and the environment.
STORMWATER MANAGEMENT FACILITYOne or a series of stormwater management practices installed, stabilized and operating for the purpose of controlling stormwater runoff.
STORMWATER MANAGEMENT OFFICER (SMO)The Village Engineer of the Village of Mamaroneck, and/or his designated agent(s) or other individual designated by the Village Manager, who will review stormwater pollution prevention plans, forward the plans to the applicable municipal board when necessary and inspect stormwater management practices.
STORMWATER MANAGEMENT PRACTICES (SMPs)Measures, either structural or nonstructural, that are determined to be the most effective, practical means of preventing flood damage and preventing or reducing point-source or nonpoint-source pollution inputs to stormwater runoff and water bodies.
STORMWATER MANAGEMENT, EROSION, SEDIMENT AND POLLUTION CONTROL PLANA plan prepared or certified by a New York State licensed engineer. These plans shall indicate the specific measures and sequencing to be used in controlling erosion, sediment and pollution on a development site during and after construction, showing the proposed use of the site and showing the methods, techniques and improvements that will be employed to control erosion, sedimentation and pollution, which shall employ best management practices.
SUBSTANTIAL IMPROVEMENTAny project or series of projects taken cumulatively for the preceding ten-year period whose cost equals or exceeds 50% of the value of the primary structure(s) on said property at the beginning of the first such project as represented in the Village of Mamaroneck Assessment rolls and/or any such project(s) within the same ten-year period which results in 50% or more of the gross floor area of the primary structure(s) on said property being changed and/or renovated.
SURFACE WATERS OF THE STATE OF NEW YORKLakes, bays, sounds, ponds, impounding reservoirs, springs, wells, rivers, streams, creeks, estuaries, marshes, inlets, canals, the Atlantic Ocean within the territorial seas of the State of New York and all other bodies of surface water, natural or artificial, inland or coastal, fresh or salt, public or private (except those private waters that do not combine or effect a junction with natural surface or underground waters), which are wholly or partially within or bordering the state or within its jurisdiction. Storm sewers and waste treatment systems, including treatment ponds or lagoons, which also meet the criteria of this definition, are not waters of the state. This exclusion applies only to man-made bodies of water, which neither were originally created in waters of the state (such as a disposal area in wetlands) nor resulted from impoundment of waters of the state.
TOTAL RECONSTRUCTIONAny project or series of projects taken cumulatively for the preceding ten-year period whose cost equals or exceeds 50% of the value of the primary structure(s) on said property at the beginning of the first such project as represented in the Village of Mamaroneck Assessment rolls and/or any such project(s) within the same ten-year period which results in 50% or more of the gross floor area of the primary structure(s) on said property being changed and/or renovated.
VILLAGE ENGINEERThe Village Engineer or consulting engineer appointed by the Board of Trustees to function as the Village Engineer.
WATERCOURSEAny natural or artificial, intermittent, seasonal or permanent and public or private water body or watercourse. A water body is intermittently, seasonally or permanently inundated with water and contains a discernible shoreline and includes ponds and lakes. A watercourse includes rivulets, brooks, creeks, streams, rivers and other waterways flowing in a definite channel with a bed and banks and usually in a particular direction.
WATERWAYA channel that directs surface runoff to a watercourse or to the public storm drain.