Seattle
Seattle, WA water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
seattle public utilities
surface water (rivers/reservoirs) · local government · PWSID WA5377050
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
Seattle is a major U.S. city and the largest in Washington, home to roughly 684,451 residents. Seattle's drinking water comes largely from the same regional sources that serve Washington: Cascade snowpack, Columbia River, Yakima River, and groundwater.
As elsewhere in Washington, the central challenge is drought. Snowpack-dependent supplies and the Yakima Basin's irrigation needs drive long-term planning despite a wet reputation.
Washington reuses an estimated 10% of its treated wastewater and maintains developing reuse programs; Seattle tracks abnormally dry to moderate drought conditions on the U.S. Drought Monitor scale.
Explore the Washington profile for statewide context, or dig into the water issues shaping Seattle below.
King County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~684,451 (largest in Washington)
- Primary sources: Cascade snowpack, Columbia River, Yakima River, and groundwater
- Drought: abnormally dry to moderate conditions
- State reuse rate: ~10% of wastewater
Statewide drought history
% of Washington in severe+ drought (Moderate (D1) now).
Source: U.S. Drought Monitor
Common questions
Is tap water safe in Seattle?
Seattle's largest water system, SEATTLE PUBLIC UTILITIES, serves about 1,161,961 people. EPA records show 0 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 1.6 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does Seattle get its water?
SEATTLE PUBLIC UTILITIES draws primarily from surface water (rivers/reservoirs), part of Washington's supply from Cascade snowpack, Columbia River, Yakima River.
Related water issues
Drought
Much of the American West is in a multi-decade dry period that researchers describe as the most severe in over a millennium, reshaping how communities plan for water.
ExploreAgricultural Demand
Agriculture accounts for the majority of consumptive water use in the West, making farm efficiency and water markets central to any supply solution.
ExplorePotable Reuse
Advanced purification turns treated wastewater into water that meets or exceeds drinking-water standards — increasingly essential in water-stressed regions.
ExploreSnowpack Decline
Mountain snow is the West's largest reservoir. As warming shifts snow to rain and melts it earlier, the timing and reliability of water supply are unraveling.
Explore