Water Supply Conditions

Below are current supply conditions for Seattle's regional water system.

September 18, 2023

Last week, the 7-day precipitation totals for the period 9/11/2023 through 9/17/2023 were 0.0 inches and 0.04 inches in our Cedar River and South Fork Tolt (SF Tolt) River watersheds, respectively.

Chester Morse Lake at the Overflow Dike was at elevation 1548.5 feet, about 0.8 feet lower than last week, and about 1.9 feet below its long-term average (based on the years 1990 to 2019).  The South Fork Tolt Reservoir at the South Fork Tolt Dam was at elevation 1725.5 feet, about 2.5 feet lower than last week, and about 16.3 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 149 million gallons per day (mgd).  That is 8 mgd less than the 157 mgd consumed during the same period last year, and 11 mgd more than the average of 138 mgd used during the same period over the years 2010-2019.

Seattle’s regional water supply remains sufficient for people and fish, despite warmer temperatures and drier-than-normal conditions. As we approach the fall, water supply conditions could change if the rainy season is delayed. As we do every year, we continue to ask customers to use water wisely. For information about ways to save water, visit www.savingwater.org.

Related resources

Public Utilities

Andrew Lee, General Manager and CEO
Address: 700 5th Avenue, Suite 4900, Seattle, WA, 98104
Mailing Address: PO Box 34018, Seattle, WA, 98124-5177
Phone: (206) 684-3000

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Seattle Public Utilities (SPU) is comprised of three major direct-service providing utilities: the Water Utility, the Drainage and Wastewater Utility, and the Solid Waste Utility.