Stormwater

What is Stormwater? 

Stormwater is runoff from rain and snowmelt which flows over the ground, driveways, streets, parking lots, and buildings that drains to streams, rivers, lakes, and the ocean. There are two main issues relating to stormwater runoff; one is the volume and intensity of the runoff water and the other relates to the potential contaminants that the water is carrying to a storm drain, lake, stream, wetland, or river. 

How is the city managing stormwater? 

Stormwater management addresses delaying, retaining, treating, or infiltrating stormwater runoff. The loss of wetland and floodplain areas from development and increased impervious surfaces necessitates the active management of stormwater runoff.  With the use of structural controls like publically owned and privately owned water quality facilities and detention ponds, to more programmatic or operational controls like street sweeping and public education and outreach, effective stormwater management requires a multipronged and collaborative approach. 

The Natural Resources Program works cooperatively with other city departments to plan and manage the Municipal Separate Storm Sewer System (MS4) within Wilsonville. The city’s MS4 is the main treatment and conveyance system for stormwater which discharges to the Willamette River. The Federal Clean Water Act, Safe Drinking Water Act, and Endangered Species Act direct the City to improve stormwater quality and protect watersheds, rivers, streams and drinking water resources. 

Key elements of the city’s stormwater management include: