Phase II Storm Water Program

Fact Sheet #1

Sensitive Waterbodies in Your Area




Storm water runoff is generally classified as excess rainwater or snowmelt that is transported to surface waters by overland flow.  Surface waters include any open body of water, such as lakes, rivers, streams or impoundments.  Storm water runoff directly impacts sensitive waterbodies in your area by discharging pollutants carried by overland storm water flow.


Since the passage of the Clean Water Act (CWA), the quality of the Nation’s waters has improved dramatically.  Despite this progress, degraded surface waters still exist.  According to the 1996 National Water Quality Inventory, 79 percent of the waterbodies are polluted by urban/suburban storm water runoff and the balance by runoff from construction sites.  Accordingly, in 1990 the U.S. Environmental Protection Agency (EPA) issued new regulations under the DWA affecting storm water runoff.  Phase I of these regulations addressed storm water runoff from: (1) “medium” and “large” Municipal Separate Storm Sewer Systems (MS4s) generally serving populations of 100,000 or greater, (2) construction activity disturbing 5 acres of land or greater, and (3) ten categories of industrial activity.  Phase II regulations, issued on December 8, 1999, addressed storm water runoff from: (1) “small” MS4s generally serving populations of less than 100,000, and (2) small construction activity disturbing 1 to 5 acres of land.



When it rains, pollutants from overland areas and impervious surfaces such as city streets, driveways, parking lots, and sidewalks are transported directly into nearby surface waters and the sensitive waterbodies in your area.  Pollutants transported from overland flow may include oils and greases (from improperly maintained automobiles), litter and debris and polycyclic aromatic hydrocarbons (from roofs and parking lots) pesticides and herbicides (from lawns and gardens) and other dissolved solids such as salts and chlorides (from de-icing agents).  In addition to pollutants from developed areas, uncontrolled runoff from ongoing construction sites yield pollutants such as sediments, petroleum products, and construction chemicals, resulting in streambed scouring, erosion and destruction of near-stream vegetative cover.  Sediment-laiden runoff, petroleum products, and construction chemicals also contribute to loss of in-stream habitats for fish and other aquatic species.  In addition, excessive sediments may cause blinding of water filtration plants, a reduction in reservoir storage capacity, and frequently contribute to increased flooding and a reduction in the navigational capacity of waterways.


Pollutants from overland flow eventually end up in the sensitive waterbodies, located in your watershed, defined as that area of land that catches the storm water runoff from rain and snowmelt.



Numerous streams, lakes, wetlands and other surface impoundments are located within the Town of Philipstown.  All the streams in Philipstown are tributaries to the Hudson River, which runs approximately 9.5 miles of the Town’s shoreline.  These sensitive waterbodies include Clove Creek and Foundary Creek to the north, Indian Brook and Philipse Creek in the center of the Town, and Annsville and Canopus Creek to the south.  Other sensitive waterbodies in Philipstown include Cold Spring Reservoir, an important source of surface drinking water supply for the Town, ponds and lakes, scattered throughout the Town.


In addition to streams, ponds and lakes, numerous freshwater wetlands, regulated by the State of New York, Department of Environmental Conservation (NYSDEC), are located in Philipstown.  Wetlands are transition areas between uplands and aquatic habitats and may include marshes, swamps, bogs and wet meadows.  To be regulated and protected under the Freshwater Wetlands Act, a wetland must be at least 12.4 acres (5 hectares) or larger.  Wetlands, smaller than 12.4 acres, are also protected if they are unusual or of a sensitive nature to the environment.  Around every regulated wetland is an adjacent area of 100 feet, provided to as a buffer to protect the wetland.



Following EPA’s framework for Unified Watershed Assessment (UWA), New York State developed a Watershed Protection and Restoration Priorities Program that identified and categorized those watersheds, within the entire state, that needed further preserving, protection and restoration.  One of the watersheds identified as a Category I Watershed (watersheds that are facing imminent threat of not meeting clean water and other natural resources goals) included the Hudson River Watershed.


According to USGS Circular 1165, on “Water Quality in the Hudson River Basin, New York and Adjacent States, 1992-95,” stream-bottom sediments in the Hudson River, contained elevated concentrations of metals, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs), which frequently exceeded federal and state water quality standards.


Residents along the shoreline rely on the Hudson River for a wide variety of uses such as boating, kayaking, fishing, swimming, picnicking and relaxing.  The Hudson River and its tributary streams serve as important habitats for a wide variety of flora and fauna.  As cited in the “Draft Philipstown Comprehensive Plan,” these natural resources contribute to the public health, habitat, recreation and the Town’s community character.  Hence, controlling the discharge of storm water pollutants into the Hudson River and its tributaries will further enhance the water quality and aquatic habitat restoration efforts of this important natural resource of the Town of Philipstown.