Seattle Public Utilities

Current Water Supply Conditions

  • Masonry Pool ReservoirChester Morse Lake Reservoir – This photo was taken on June 17, 2018 by Kevin Johnson

June 19, 2018

Last week, 1.46 inches and 0.87 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 1561.6 feet, about 0.6 feet lower than last week, and about 0.8 feet above its long-term average (based on the years 1985 to 2014).  Masonry Pool Reservoir at Masonry Dam was at elevation 1561.6 feet, about 0.5 feet lower than last week, and about 0.8 feet above its long-term average.  The South Fork Tolt Reservoir at the South Fork Tolt Dam was at elevation 1760.3 feet, about 1.0 feet lower than last week, and about 2.1 feet below 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 145 million gallons per day (mgd).  That is higher than the 132 mgd consumed during the same period last year, and more than the average of 144 mgd used during the same period over the years 1999-2014.

Related Links

Current water supply graphs (pdf)
Landsburg Mitigation
Water Sources and Treatment