Why is Stormwater Important

Stormwater from a rain event or melting snow can pick Index and move sediment and a variety of pollutants. Because the stormwater transports whatever is left on our lawns and roads, individual actions make a difference in determining the kinds and amounts of pollution.

In more developed areas, there is a greater percentage of impervious surfaces, and therefore more stormwater, and with more water, more pollutants can be transported.  In addition, the kind of surface can affect the quality and quantity of stormwater.  Forested areas retain more water than lawns:  lawns retain more water than bare soil.   
Uncontrolled erosion and stormwater can result in increased water runoff volume, increased rate of water runoff, soil movement and sediment accumulation which can damage our stormwater conveyance system of streams, brooks, swales, wetlands and waterbodies. This damages results in the destruction of habitat, accelerated lake degradation, increased pollutant loading and greater increase in the occurrence and impacts of flooding.

Polluted runoff degrades our lakes, rivers, wetland and other waterways and can then get into our groundwater. 

  • Transported sediment clouds the waterways and interferes with the habitat of fish and plant life.  Sediment often comes from construction activities or areas of erosion.
  • Nutrients such as phosphorus and nitrogen can promote the overgrowth of algae, can deplete oxygen in the waterways, can be harmful to other aquatic life and can alter the habitat ecology.  
  • Toxic chemicals from automobiles and home supplies, and the careless application of pesticides, herbicides and fertilizers all threaten the health of the receiving waterways and can kill fish and other aquatic life.
  • Bacteria from animal wastes and illicit connections to sewerage systems can make nearby lakes and streams unsafe for wading, swimming and use as drinking water supplies.

A large portion of the Town of Lewisboro is located in the NYC watershed in which the main pollutant of concern is phosphorus.

In Lewisboro, all of our stormwater runoff eventually goes into someone’s drinking water supply.  

Lewisboro’s surface water, although a part of its natural beauty, is also largely a result of human action. The Cross River Reservoir and Muscoot Reservoir are components of the New York City drinking water system.   Scotts Reservoir and Browns Reservoir, in southeast Lewisboro, are part of the drinking water supply for Connecticut residents.  While Lakes Waccabuc, Oscaleta, and Rippowam are natural, Lakes Katonah, Kitchawan, Truesdale, and Timber are all manmade.  In addition, the Town is laced with streams, creeks, and many small ponds.  Clean surface water enhances property values and aesthetic values, provides recreation opportunities, and protects the drinking water supply.