Seattle Public Utilities Mami Hara, General Manager/CEO

Current Water Supply Conditions

  • Masonry Pool ReservoirMasonry Pool – This photo was taken on August 13, 2017 by Tanner Mawhinney.

August 15, 2017

Last week, 0.26 inches and 0.48 inches of precipitation were recorded in our Cedar River and South Fork Tolt River watersheds, respectively.

Chester Morse Lake at the Overflow Dike was at elevation 1555.4 feet, about 1.3 feet lower last week, and about 3.0 feet above its long-term average (based on the years 1989 to 2005). Masonry Pool Reservoir at Masonry Dam was at elevation 1555.3 feet, about 1.3 feet lower than last week, and about 6.5 feet above its long-term average. The South Fork Tolt Reservoir at the South Fork Tolt Dam was at elevation 1748.4 feet, about 2.5 feet lower than last week, and about 2.6 feet below its long-term average. Water releases from reservoir storage are actively being managed for water supply, hydropower, fish habitat and construction management objectives for both the Cedar and South Fork Tolt Rivers.

Water consumption for the previous seven days averaged approximately 184 million gallons per day (mgd). That is higher than the 158 mgd consumed during the same period last year, and more than the average of 180 mgd used during the same period over the years 1999-2014.

Current water supply graphs (pdf)