About Your Water – An Overview

Cedar River Seattle Public Utilities


From 1964 until 2012, all of our water was sourced from the 12,500 acre South Fork Tolt River Watershed, located on the western foothills of the North Cascade mountains in east King County.

This area receives between 90 to 160 inches of precipitation each year, which produces approximately 100 million gallons of drinking water per day.

In January 2012, North City Water District completed a new connection with the Seattle Public Utilities NW regional supply which draws water from both the Tolt and Cedar River Watersheds.  Our new Cedar River source (pictured above) offers an excellent back-up as well as increased reliability for our ratepayers’ water supply.


Before entering the main supply lines, water from the South Fork Tolt River Watershed passes through a screen house to filter out debris, and then through an innovative filtration plant that uses ozone to disinfect the water and carbon filters to remove particulate matter. Lastly, water is treated to provide ongoing disinfection, fluoridation, and corrosion control.

Infrastructure and Capacity

North City Water District maintains the following infrastructure to supply water service to roughly 25,000 customers within an area of approximately 5 square miles, including parts of both City of Shoreline and the City of Lake Forest Park:

• Two reservoirs (3.7 million gallons and 2.0 million gallons)
• Two Supply Stations
• Three Booster Stations
• Eleven Pressure Reducing Stations
• Ninety-five miles of water main (piping)


Single family residences: 389,681,172 gallons
Multi-family residences: 91,491,872 gallons
Commercial businesses: 46,620,596 gallons
Wholesale uses (Fircrest): 18,694,016 gallons
Government (schools, parks, etc.): 11,948,552 gallons

Water System Plan

Learn more about North City Water District’s Comprehensive Water System Plan by clicking here >