What is Stormwater?
Stormwater is water from rain or melting snow that does not soak into the ground. When land is developed, the hard impervious surfaces of roofs, parking lots, roads, and buildings prevent water from absorbing into the ground. Water flows off of these surfaces and becomes stormwater. As it flows, this runoff collects and transports pollutants such as soil, pet waste, salt, pesticides, fertilizer, oil and grease, yard waste, litter and other contaminants. In developed areas, stormwater drains are installed to capture and redirect water that would otherwise flood roads, buildings and parking lots. In areas with Municipal Separate Storm Sewer Systems, this runoff is piped and/or directed into rivers, lakes and streams.
The impacts of stormwater on water quality:
- When it rains, soil will erode and travel into local waterways. This clouds water and degrades habitat for fish and water plants.
- Nutrients such as phosphorus and nitrogen from fertilizers and animal wastes promote the growth of algae, which crowd out other aquatic life.
- Toxic chemicals such as antifreeze and oil from leaking cars, carelessly applied pesticides, and zinc from galvanized metal gutters and downspouts threaten the health of fish and other aquatic life.
- Bacteria and parasites from pet, waterfowl and other animal waste can affect nearby inland lakes and streams.
- As many people have discovered, stormwater can be a problem closer to home, flowing into basements, where it can be difficult and hazardous to clean up.
- Stormwater can also flow down an abandoned well or poorly sealed well casing (pipe) and contaminate drinking water.There are many ways to reduce the risks posed by stormwater including stewardship practices that keep the pollutants out of stormwater as well as best management practices to reduce the amount of stormwater runoff. Go to the take action page to see how you can help reduce harmful contaminants from getting in the water supply.