Jackson Lake marina dries up, dam to hit low levels into fall

Jackson Lake sits at about 33% capacity in late August, far below the roughly 88% that’s typical for this time of year, according to Brian Stevens of the U.S. Bureau of Reclamation’s Upper Snake operations. With record-dry heat and a warm, sparse-fall forecast, the dam could approach near-zero territory, with an expected 1% to 10% full range by the end of fall. Releasing water at more than average rates—5,000 cubic feet per second through mid-September—helps meet downstream irrigation needs, but warmer, low flows strain the entire Upper Snake’s nine-reservoir system. Stevens said the chance of Palisades Reservoir losing power generation is under 50%. Warmer releases from Jackson Dam can reduce dissolved oxygen, stressing aquatic life. In July, Wyoming Game and Fish issued a voluntary Snake River fishing closure after temperatures held at or above 70°F for several days.