Water Supply Conditions
The current supply conditions for Seattle's regional water system.
Chester Morse Lake, December 21, 2025. This photo was taken by Kevin Johnson.
December 22, 2025
Last week, the 7-day precipitation total for the period 12/15/2025 through 12/21/2025 was approximately 8.65 inches in the Cedar River watershed and 5.56 inches in the South Fork (S.F.) Tolt River watershed.
Chester Morse Lake at the Overflow Dike was at an elevation of 1554.0 feet, about 2.5 feet lower than last week and about 3.1 feet higher than its long-term average (based on the years 1990 to 2019). The S.F. Tolt Reservoir at the S.F. Tolt Dam was at an elevation of 1759.4 feet, about 4.5 feet higher than last week and about 6.7 feet higher than 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 S.F. Tolt Rivers.
Water consumption for the previous seven days averaged approximately 103 million gallons per day (mgd). That is less than the 104 mgd consumed during the same period last year, and less than the 104 mgd used during the same period over the years 2010-2019.
Based on current conditions and forecasts, Seattle anticipates the regional water system will have sufficient water supply for people and fish. As we monitor the important return of fall rains, we anticipate having sufficient water for people and fish this fall but continue to ask customers to always use water wisely. For information about ways to save water, visit the Saving Water Partnership website.