Seattle Public Utilities

Current Water Supply Conditions

  • Masonry Pool ReservoirChester Morse Lake Reservoir – This photo was taken on October 14, 2018 by Kevin Johnson.

October 16, 2018

Last week, 1.41 inches and 1.13 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 1546.5 feet, about 1.2 feet lower than last week, and about 0.1 feet above its long-term average (based on the years 1985 to 2014).  Masonry Pool Reservoir at Masonry Dam was at elevation 1515.6 feet, about 2.4 feet lower than last week, and about 13.9 feet below its long-term average.  The South Fork Tolt Reservoir at the South Fork Tolt Dam was at elevation 1727.7 feet, about 1.4 feet lower than last week, and about 12.8 feet below its long-term average.  Water releases from reservoir storage are actively being managed for water supply and fish habitat 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 110 mgd consumed during the same period last year, and less than the average of 121 mgd used during the same period over the years 1999-2014.

Based on current conditions and forecasts, Seattle Public Utilities has sufficient supply to meet demands this fall for both people and fish.  As always, SPU will continue to carefully monitor conditions daily and anticipate the return of the fall rains. 

Using water wisely is something SPU always asks its customers to do. For information about ways to save water, visit

Related Links

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