Stormwater runoff occurs when precipitation from rain or snowmelt flows over the ground.  Hard (impervious) surfaces like roofs, driveways, sidewalks and streets prevent the stormwater from soaking into the ground.

 

Stormwater can pick up debris, chemicals, dirt, and other pollutants and flow into a storm sewer  or directly to a lake, stream, river, wetland, or coastal water. Anything that enters a storm sewer system is discharged untreated into the waterbodies we use for swimming and fishing.

 

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, clog fish gills and smother shellfish bottom.

 

Excess nutrients from over-fertilization and animal waste 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. Excess nutrients also contribute to the growth of aquatic weeds.

 

Bacteria and other pathogens can wash into swimming areas and create health hazards, often making beach closures necessary.

 

Debris such as plastic bags, six-pack rings, bottles, and cigarette butts - washed into waterbodies can choke, suffocate, or disable aquatic life like ducks, fish, turtles, and birds.

 

Household hazardous wastes like insecticides, pesticides, paint, solvents, used motor oil, and other auto fluids can poison aquatic life. Land animals and people can become sick from eating diseased fish and shellfish or ingesting polluted water.

 

Watch a 9-minute EPA video on low impact development techniques like capturing stormwater for reuse in rain barrels and cisterns, slowing it down so it can infiltrate through installing rain gardens and vegetated swales, and cool ideas like green roofs.