Seattle Public Utilities

Current Water Supply Conditions

  • Masonry Pool ReservoirMasonry Pool Reservoir – This photo was taken on December 09, 2018 by Kevin Johnson.

December 11, 2018

Last week, 1.96 inches and 1.36 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 1552.0 feet, about 1.7 feet lower than last week, and about 2.6 feet above its long-term average (based on the years 1985 to 2014).  Masonry Pool Reservoir at Masonry Dam was at elevation 1551.6 feet, about 1.7 feet lower than last week, and about 6.4 feet above its long-term average.  The South Fork Tolt Reservoir at the South Fork Tolt Dam was at elevation 1746.7 feet, about 0.5 feet lower than last week, and about 3.7 feet below its long-term average.  Water releases from reservoir storage are actively being managed for water supply, fish habitat and flood management objectives for both the Cedar and South Fork Tolt Rivers.

Water consumption for the previous seven days averaged approximately 103 million gallons per day (mgd).  That is higher than the 102 mgd consumed during the same period last year, and less than the average of 112 mgd used during the same period over the years 1999-2014.

Related Links

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