Description
Lake Sammamish, Lake Washington, Lake Washington Ship Canal, and the Sammamish River are key salmon migratory bottlenecks where warm water and low dissolved oxygen can block or delay migration and exacerbate other stresses to salmon, such as predation and disease, that limit recovery efforts. Lake Sammamish is the year-round home for kokanee to rear before returning to spawn in tributary streams, so addressing key survival issues is critical. King County will work with partners to plan, implement, and coordinate actions to improve water quality and habitat conditions in these areas. For large lakes, priority actions include reconnecting and enhancing creek mouths and shallow-water rearing habitat, addressing impacts on the aquatic environment from artificial light at night, reducing predation on juvenile salmon and kokanee by invasive predatory fish, and controlling invasive aquatic weeds in Lake Sammamish. Priority actions in key salmon migratory areas include advancing and funding feasible engineered cold water supplementation solution(s) in the Lake Washington Ship Canal, and implementing cold water refuge and instream flow supplementation project opportunities in the Sammamish River.