Program Overview
The Cascade Supply Program (CSP) will provide a resilient water supply to our member agencies well into the future and will involve miles of transmission and distribution pipelines, storage tanks, a re-chlorination station, and more in the future. Planning for the CSP began in late 2025. The CSP will be delivered in phases, shown on the map below.
Phase I of the CSP focuses on planning and constructing a transmission system to connect the Tacoma water supply from Tacoma’s Pipeline 5 to the Cascade member service area. Early conceptual plans include a large diameter transmission pipeline that could span around 20 miles, one or more storage tanks, a re-chlorination station, and regional supply connections which will deliver up to 32.5 million gallons per day (MGD) of water.
Map of anticipated CSP Phase Areas (Illustrative Only – Subject to Change)
Program Schedule
Phase I is underway and aims to provide Tacoma Public Utilities (TPU) water supply to the member service area by 2041. Construction of Phase I is expected to begin in the 2030s. Cascade members will begin receiving TPU water supply in 2041. Design and construction of other program components will be included in future phases.