Stormwater runoff is rainfall that flows over land surface and into impervious areas such as paved streets, roads, driveways, parking lots, building rooftops, and other paved surfaces that do not allow water to soak into the ground. Because of this, water "runs off" into the City's stormwater drainage system and into neighboring wetlands, streams and rivers.
Stormwater runs off streets, lawns, farms, as well as construction and industrial sites, where it picks up fertilizers, dirt, sediment, pesticides, oil & grease and many other pollutants on the way to local waterways. Unlike pollution from industry or sewage treatment facilities, which is caused by a discrete number of sources, stormwater pollution is caused by the daily activities of people everywhere.
Stormwater discharges are a significant contributor to local water quality impairments, possibly preventing recreational use or damging habitat for fish, other aquatic organisms and wildlife.