Regional Water Supply

Within the central Puget Sound’s three-county region – King, Pierce and Snohomish counties – the supply of and demand for water is impressively balanced. This is due in large part to significant system improvements and enhancements by regional water suppliers. The Forum’s wise planning and collaborative approach have helped ensure the region’s reliable supply of water.


The Regional Water Supply Outlook is a comprehensive report periodically released by the Water Supply Forum. It presents an overview of existing water demands and supplies across King, Pierce and Snohomish counties, with an assessment of future supply/demand issues, water use trends, and the challenges water providers face. Full reports were issued in 2001 and 2009. In 2012 the Water Supply Forum released an abbreviated Regional Water Supply Update..


Individual utilities are required to develop comprehensive water system plans that address a 20-year planning period with emphasis on the initial six-year period. Plan requirements are maintained by the Washington State Department of Health. Seattle Public Utilities, Tacoma Water, the City of Everett and Cascade Water Alliance all have plans accessible online.