Water Supply Conditions

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

May 29, 2023

Last week, the 7-day precipitation totals for the period 5/21/2023 through 5/27/2023 were approximately 0.03 inch and 0.61 inch in our Cedar River and South Fork Tolt (SF Tolt) River watersheds respectively.

Chester Morse Lake at the Overflow Dike was at elevation 1564.2 feet, about 0.6 foot lower than last week, and about 3.1 feet above its long-term average (based on the years 1990 to 2019).  Masonry Pool Reservoir at Masonry Dam was at elevation 1564.1 feet, about 0.6 foot lower than last week, and about 3.1 feet above its long-term average.  The South Fork Tolt Reservoir at the South Fork Tolt Dam was at elevation 1754.6 feet, about 0.4 foot lower than last week, and about 7.4 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 141 million gallons per day (mgd).  That is about 30 mgd more than the 111 mgd consumed during the same period last year, and more than the average of 123 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 this spring. As always, 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.