Stormwater management - Southwest Washington

Rain on roof


About stormwater

We get a lot of rain in the Pacific Northwest. Rain becomes stormwater runoff when it flows off roofs, yards, streets and parking lots and into our streams, lakes, rivers, wetlands and groundwater. As runoff washes over these surfaces, it picks up dirt, pet waste, litter, motor oil and a host of other pollutants and dumps them into nearby waterways.

Stormwater runoff is managed by channeling it through specially built landscaped and structural features called stormwater facilities. They remove pollutants and slow stormwater flowing into our waterways. Both functions are critical to reduce the risk of flooding and protect the health of our streams, lakes, wetlands and drinking water. Ponds, inlets, ditches and drains are part of our community's stormwater management system. 

Although some stormwater treatment facilities might be maintained by your city or county, stormwater facilities often have private owners, including homeowner associations (HOAs), who must inspect and maintain them. These private facilities may serve housing developments, schools, churches, commercial buildings and parking lots.

This website gives an overview of types of facilities you or your association must maintain, checklists that show how to maintain them and fix problems, how to recognize facilities in your development, whom to contact with questions and other resources.