Stormwater runoff is the rainfall or snowmelt that runs off permeable surfaces or impervious surfaces like roads, buildings, sidewalks or compacted ground surfaces.
Stormwater can flow directly to streams and lakes or it may be transported by municipal storm drain systems. Unlike sanitary sewers, storm sewers do not lead to treatment plants, but drain directly into our streams and lakes.
And according to a six year study conducted by EPA, urban stormwater contains concentrations of pollutants that are equal to or larger than non-urban runoff.
As communities grow, they often experience more stormwater runoff problems due to their increasing impervious surface areas. Rainfall and snowmelt that would normally infiltrate into the soil becomes runoff. This increases both the volume and rate of runoff, which leads to flooding, streambank erosion, and potential damages to public and private property and water quality.
The Iowa Department of Natural Resources is working in a variety of ways to improve stormwater quality. Certain activities and specific municipalities and universities must obtain permits with requirements that are intended to reduce the impact of stormwater on our lakes and streams. In addition, DNR and its partners have developed a number of stormwater "tools" to assist developers, builders, cities and individual Iowans.
Manuals and Brochures
Stormwater Regulations and Permitting
Stormwater DVD Series
Learn how stormwater runoff can affect water quality and what you can do to help.
Other Stormwater Resources
General stormwater pollution issues:
Stormwater regulation issues: