Water Supply Conditions

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

March 20, 2023

Last week, the 7-day precipitation totals for the period 3/13/2023 through 3/19/2023 were approximately 1.3 inches and 0.7 inch in our Cedar River and South Fork Tolt (SF Tolt) River watersheds respectively.

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.  Reservoir water elevation status as of March 20, 2023:

  • Chester Morse Lake at the Overflow Dike was at about elevation 1550.5 feet. The elevation seven days ago was about 1550.5. The long-term average for this day (years 1990 to 2019) is 1553.0.
  • Masonry Pool Reservoir at Masonry Dam was at about elevation 1544.0 feet. The elevation seven days ago was about 1549.9. The long-term average for this day is 1550.28.
  • The SF Tolt Reservoir at the SF Tolt Dam was at about elevation 1743.7 feet. The elevation seven days ago was about 1744.2. The long-term average for this day is 1757.1.

Water consumption for the previous seven days averaged approximately 103 million gallons per day (mgd). Consumption during the same period last year averaged approximately 103 mgd and consumption during this period over the years 2010-2019 averaged approximately 103 mgd.

Based on current conditions and forecasts, Seattle anticipates the regional water system will have sufficient water supply for people and fish this winter. 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.