Seattle Public Utilities Mami Hara, General Manager/CEO

Current Water Supply Conditions

  • Masonry Pool ReservoirChester Morse Lake Reservoir – This photo was taken on May 22, 2017 by Aaron Erman.

May 23, 2017

Last week, 3.11 inches and 2.87 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 1562.1 feet, about 0.8 feet higher than last week, and about 2.7 feet above its long-term average (based on the years 1989 to 2005). Masonry Pool Reservoir at Masonry Dam was at elevation 1562.0 feet, about 0.8 feet higher than last week, and about 3.0 feet above its long-term average. The South Fork Tolt Reservoir at the South Fork Tolt Dam was at elevation 1762.4 feet, about the same as last week, and about 0.6 feet above its long-term average. Water releases from reservoir storage are actively being managed for water supply, hydropower, fish habitat and flood management objectives for both the Cedar and South Fork Tolt Rivers.

Water consumption for the previous seven days averaged approximately 109 million gallons per day (mgd). That is lower than the 128 mgd consumed during the same period last year, and less than the average of 128 mgd used during the same period over the years 1999-2014.

Current water supply graphs (pdf)