Seattle Public Utilities

2019 Water System Plan

Seattle Public Utilities provides reliable, high-quality drinking water to 1.4 million people who live in Seattle, King County and portions of southern Snohomish County. Thoughtful planning and strategic investment in our drinking water supplies and infrastructure will help ensure our region has enough water to meet the needs of our customers for decades.

To plan for long-term needs and meet regulatory requirements, Seattle Public Utilities regularly updates its Water System Plan. The 2019 Water System Plan is the latest update. It describes near- and long-term plans for the regional water system. It also focuses on updates to the water system and programs since the 2013 Water System Plan was completed.

The Plan describes how Seattle Public Utilities:

  • meets current and future water demands,
  • ensures high-quality drinking water,
  • enhances system reliability and resiliency, and
  • cost-effectively invests in and maintains the water system.

Public Review Draft and SEPA DNS Released for Public Comment

The Public Review Draft of the 2019 Water System Plan was released on March 12, 2018 and is available for public review and comment through June 1, 2018. Comments about the plan can be sent to Joan Kersnar (see contact information below). The final plan will address comments received on the Public Review Draft. It will then be reviewed by the Mayor of Seattle and the Seattle City Council in the fall of 2018.

SEPA Process

On March 12, 2018, Seattle Public Utilities issued a threshold determination for the 2019 Water System Plan. This was issued in compliance with the State Environmental Policy Act (SEPA) under RCW 43.21C and the Seattle SEPA Ordinance, Chapter 25.05 of the Seattle Municipal Code. The comment deadline for the SEPA Determination of Non-significance (DNS) is March 26, 2018, and the appeal deadline is April 2, 2018.

Contact Information

Send comments about the 2019 Water System Plan by June 1, 2018 to:

Joan Kersnar, Drinking Water Planning Manager
Seattle Public Utilities
P.O. Box 34018; Seattle, WA 98124-4018
(206) 684-0839 or

Archived Plans



This page was last updated on 3/12/2018.