The King County Flood Control District invests in regional programs and projects to reduce the risk to people and property from river flooding and channel migration in King County. King County is home to several river watersheds that carry water flows from the Cascade Mountains to Puget Sound. These rivers pass through forested, agricultural and highly urbanized areas. Flooding is a significant threat. Floods most commonly occur in King County from November through February during periods of heavy rainfall and rapid snowmelt. Historically, King County rivers have flooded in every month but August. River flooding has led to 12 presidentially declared disasters in King County since 1990.
The King County Flood Control District makes investments in the following areas: Cedar/Issaquah/Sammamish River Basin, Green River Basin, Snoqualmie/South Fork Skykomish River Basin (including Raging & Tolt Rivers), Seattle and White River Basin.