What is stormwater runoff and what are its effects?
Conceptual watershed (rainwater washing into streams, rivers, bays, and oceans from various earth surfaces) showing the relation between nutrient sources, streams, and groundwater.
An Introduction to Stormwater - video on YouTube (The Jordan Cove Urban Watershed Section 319 National Monitoring Program Project)
Reducing Runoff: Slow It Down, Spread It Out; Soak It In - EPA video on YouTube
Water is essential for life. It is our most precious natural resource. Surface waters such as rivers, lakes, and the Chesapeake Bay can easily become polluted. Stormwater runoff comes from many sources. The U.S. Environmental Protection Agency estimates that at least 50 percent of our nation's water pollution is caused by stormwater runoff.
When it rains or snows, runoff picks up and carries a wide variety of pollutants into our storm water system. These pollutants then flow into our local waterways and into the Chesapeake Bay.
Stormwater runoff pollutants:
- pet waste
- yard waste such as leaves, grass clippings, and pine needles
- automotive products such as motor oil and antifreeze
- hazardous waste such as cleaners and paints
- sediment - soil, sand, silt, clay.
The nutrients in fertilizer such as nitrogen and phosphorus not only cause grass to grow, but an excessive amount also causes algae to grow in our waterways. Algae blooms cause fish kills and block sunlight for the underwater vegetation needed by fish and shellfish for food and cover. Pet waste, like human waste, is also disease-carrying raw sewage. Raw sewage in our waterways can make water unusable for fishing, swimming, and drinking.
Automotive products are toxic and are harmful to humans and animals as well as the environment. Antifreeze is particularly hazardous to pets, which may drink from contaminated puddles. These toxins in our waterways can make water unusable for fishing, swimming, and drinking.
Sediment from stormwater runoff clogs fish gills, blocks sunlight for underwater vegetation, and smothers shellfish and fish-spawning areas. It is the largest contributor of storm water pollution by volume.