Understanding Stormwater

Stormwater is the water that runs off of the land surface when it rains or snow melts. It enters the Town's storm drain system and flows directly to local lakes, streams and wetlands. Stormwater runoff from undeveloped land is typically low since most rain or snow melt infiltrates into the ground or is lost to evaporation. Additional runoff from developed areas is created from impervious surfaces like streets, parking lots, and rooftops that prevent stormwater from naturally soaking into the ground.

Stormwater from developed areas typically contains a number of pollutants, such as oil and grease from roadways and parking lots, pesticides and fertilizers from lawns, sediment from construction sites, sand and dirt from roadway maintenance practices, and carelessly discarded trash such as cigarette butts, wrappers, plastic bags, and plastic bottles. When these pollutants enter water bodies, they can contaminate drinking water supplies, hinder recreation activities, and harm aquatic and other wildlife habitats.

In addition to washing pollutants into our surface waters, improperly managed stormwater runoff can result in soil erosion and flooding.

Polluted stormwater runoff can have many adverse effects on plants, fish, animals, and people.

• Sediment can cloud the water and make it difficult or impossible for aquatic plants to grow. Sediment also can destroy aquatic habitats.
• Excess nutrients can cause algae blooms. When algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic organisms can't exist in water with low dissolved oxygen levels.
• Bacteria and other pathogens can wash into swimming hazards, often making beach closures necessary.
• Debris—plastic bags, six pack rings, bottles and cigarette butts—washed into waterbodies can choke, suffocate or disabled aquatic life like ducks, fish, turtles, and birds.
• Household hazardous waste like insecticides, pesticides, paint, solvents, used motor oil, and other auto fluids can poison aquatic life. Land animals and people can become sick or die from eating diseased fish and shellfish or ingesting polluted water.
• Polluted stormwater often affects drinking water sources. This, in turn, can affect human health and increase drinking water treatment costs.