What is Stormwater Runoff?

Stormwater runoff occurs when precipitation from rain or snow-melt flows over the ground. Impervious surfaces such as driveways, sidewalks and streets prevent stormwater from naturally soaking into the ground.

Why is Stormwater Runoff a Problem?

Stormwater can pick up debris, chemicals, dirt, and other pollutants and flow into a storm sewer system 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, fishing, and providing drinking water.

The Effects of Pollution:

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.


Hazardous wastes like insecticides, solvents, used motor oil and other auto fluids can poison aquatic life. (Photo: Town of Addison)

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

Stormwater Pollution Solutions

Residential

Recycle or properly dispose of household products that contain chemicals, such as insecticides, pesticides, paint, solvents, and used motor oil and other auto fluids. Don’t pour them onto the ground or into storm drains.

Excess fertilizers and pesticidesapplied to lawns and gardens wash off and pollute streams. In addition, yard clippings and leaves can wash into storm drains and contribute nutrients and organic matter to streams.

• Lawn care
  • Don’t overwater your lawn. Consider using a soaker hose instead of a sprinkler.
  • Use pesticides and fertilizers sparingly. When use is necessary, use these chemicals in the recommended amounts. Use organic mulch or safer pest control methods whenever possible.
  • Compost or mulch yard waste. Don’t leave it in the street or sweep it into storm drains or streams.
  • Cover piles of dirt or mulch being used in landscaping projects.
• Septic systems
  Leaking and poorly maintained septic systems release nutrients and pathogens (bacteria and viruses) that can be picked up by stormwater and discharged into nearby waterbodies. Pathogens can cause public health problems and environmental concerns.
  • Inspect your system every 3 years and pump your tank as necessary (every 3 to 5 years).
  • Don’t dispose of household hazardous waste in sinks or toilets.
• Auto care
  Washing your car and degreasing auto parts at home can send detergents and other contaminants through the storm sewer system. Dumping automotive fluids into storm drains has the same result as dumping the materials directly into a waterbody.
  • Use a commercial car wash that treats or recycles its wastewater, or wash your car on your yard so the water infiltrates into the ground.
  • Repair leaks and dispose of used auto fluids and batteries at designated drop-off or recycling locations.
• Pet Waste
  Pet waste can be a major source of bacteria and excess nutrients in local waters.
  • When walking your pet, remember to pick up the waste and dispose of it properly. Flushing pet waste is the best disposal method. Leaving pet waste on the ground increases public health risks by allowing harmful bacteria and nutrients to wash into the storm drain and eventually into local waterbodies.

Residential Landscaping

Permeable Pavement — Traditional concrete and asphalt don’t allow water to soak into the ground. Instead these surfaces rely on storm drains to divert unwanted water. Permeable pavement systems allow rain and snow-melt to soak through, decreasing stormwater runoff.

Rain Barrels —You can collect rainwater from rooftops in mosquito-proof containers. The water can be used later.

Rain Gardens and Grassy Swales — Specially designed areas planted with native plants can provide natural places for rainwater to collect and soak into the ground. Rain from rooftop areas or paved areas can be diverted into these areas rather than into storm drains.

Vegetated Filter Strips — Filter strips are areas of native grass or plants created along roadways or streams. They trap the pollutants stormwater picks up as it flows across driveways and streets.