Where does runoff come from?

Stormwater runoff from our communities’ streets, driveways, parking lots, and rooftops can degrade the quality of our lakes, rivers, streams, wetlands and sometimes, shallow groundwater resources. Urban, suburban, and agricultural stormwater runoff carries pollutants such as nutrients, pathogens, and sediment. When the amount (volume) and speed (rate) of runoff increases, such as during and after storms, outcomes can include localized and downstream flooding.