Responding to Low Flows on the Dungeness River - an Experience from the Washington Drought 2015 Playbook

With its origins deep in the Olympic Mountains, the Dungeness River suffers from low summer stream flows and increasing demands for irrigation and residential water use.  The long term water supply issues are being addressed through the setting of instream flow rules in Washington State Administrative Code and through continued local cooperation and coordination.  However, shallow summertime stream flows still occur in the lower Dungeness River between the mountains and the Strait of Juan de Fuca because a vast gravel build-up forces surface flows to spread across the sediment.  These extremely shallow riffles can inhibit salmon migrations beginning in mid-summer.  In 2015, the pink salmon return was forecasted at 1.3 million fish, and stream flows were forecasted at less than 40 percent of normal.  Washington Department of Fish and Wildlife and the Jamestown s'Klallam Tribe began planning early for in-river modifications that could increase riffle depth and maintain pools through the lower Dungeness River.  Using portable flow constriction devices and moving rocks by hand, sufficient stream depths were created so that hundreds of thousands of pink salmon were able to migrate upstream to their spawning grounds.