Seattle Public Utilities

Current Water Supply Conditions

  • Masonry Pool ReservoirChester Morse Lake Reservoir – This photo was taken on April 16, 2018 by Kevin Johnson.

April 17, 2018

Last week, 6.73 inches and 6.42 inches of precipitation were recorded in our Cedar River and South Fork Tolt River watersheds, respectively.  Snowpack is continuing to build and is above the long-term median for this time of the year. 

Chester Morse Lake at the Overflow Dike was at elevation 1562.3 feet, about 5.0 feet higher than last week, and about 7.6 feet above its long-term average (based on the years 1985 to 2014).  Masonry Pool Reservoir at Masonry Dam was at elevation 1562.3 feet, about 5.1 feet higher than last week, and about 8.9 feet above its long-term average.  The South Fork Tolt Reservoir at the South Fork Tolt Dam was at elevation 1763.2 feet, about 2.3 feet higher than last week, and about 3.9 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 99 million gallons per day (mgd).  That is less than the 101 mgd consumed during the same period last year, and less than the average of 111 mgd used during the same period over the years 1999-2014

Current water supply graphs (pdf)