Alderwood Water & Wastewater District

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Where Your Drinking Water Comes From

We purchase your drinking water from the City of Everett. The water comes from Spada Reservoir, located at the headwaters of the Sultan River about 30 miles east of Everett. The Spada Reservoir, created in 1964 in partnership with the Snohomish County PUD, holds about 50 billion gallons of water.

From Spada Reservoir, the water travels through a pipeline to the City of Everett Treatment facility at the Chaplain Reservoir. Chaplain Reservoir is about 8 miles downstream from Spada Reservoir and holds about 4.5 billion gallons of water.

Spada Reservoir is in the Sultan Basin Watershed. A watershed is a geographic area where all precipitation drains into a single body of water. In the Sultan Basin Watershed, rain and snow melt from the Cascade Mountains flow into Spada Reservoir. The Sultan Basin Watershed covers an area of about 84 square miles and is one of the wettest watersheds on the west side of the Cascade Mountains. The average rainfall is about 165 inches, or 5 times our local rainfall. To protect the naturally pristine water in Spada Reservoir, water quality in the Sultan Basin is carefully monitored.