Stormwater runoff occurs when precipitation from rain or snowmelt flows over the ground. Impervious surfaces like driveways, sidewalks and streets prevent stormwater from naturally soaking into the ground. Stormwater can pick up debris, chemicals, dirt and other pollutants and flow into a storm sewer system or directly to a lake, stream, river, wetland, or coastal water. Anything that enters a storm sewer system is discharged untreated into the waterbodies used for swimming, fishing and providing drinking water. Please click on each of the brochures below to learn more about how we can all be better stewards of clean water.