Historic agreement between Tacoma Water and Cascade Water Alliance provides benefits to water customers across the region

Cascade, who provides water to Bellevue, Issaquah, Kirkland, Redmond, Sammamish Plateau Water, Skyway Water and Sewer District, and Tukwila, would start with a small amount of water being delivered by Tacoma Water in 2041, and steadily increase that amount to 24 million gallons a day by 2060. After 2062, Tacoma Water would be delivering about half of that, around 12 million gallons a day. Cascade’s Board previously approved the contract on January 22nd, 2025.

Currently, there is no infrastructure connecting the Tacoma and Cascade water systems. Under this agreement, Cascade will finance, construct, operate and maintain a water transmission main from Tacoma’s pipeline 5 to Cascade’s customers.

This newly approved agreement will have wide-ranging benefits for water supply and reliability across the region. It positions both water utilities to maximize future regional water projects and make shared investments in infrastructure. It helps support regional conservation efforts and coordinates more effective water management practices. Cascade and Tacoma Water will also enjoy enhanced supply resiliency through broader access to regional water supply, mitigating regional risks associated with climate change and potential drought, wildfire, water quality, and seismic events.

Upon approval of this agreement by the Tacoma City Council, Tacoma Public Utilities Board Chair John O’Loughlin praised the benefits to Tacoma Water customers.  “Tacoma Water has a long history of looking decades down the road to ensure good stewardship of this vital, public resource- water. Our agreement with Cascade provides benefit for today’s customers and for generations yet to come. The benefits include affordable rates, a resilient and reliable water supply and an invaluable connection among the largest water systems in the state. Whatever condition the latter half of this century presents for the regional water supply, Tacoma Water will be in a much safer, stronger position with this agreement in place.”

“This agreement with Tacoma Water is a historic milestone for Cascade and the region,” said Penny Sweet, Cascade Board Chair and City of Kirkland Councilmember. “Connecting our systems is a first step toward transforming the region’s approach to drinking water. Regional collaboration and partnerships are part of Cascade’s mission and how we build a flexible, resilient water supply system. We plan decades in the future and use available regional supply before building new supply. This agreement gives Cascade more time to plan and save for the next source of supply, meaning our residents have a reduced cost of water over time and lower long-term rate forecasts. We look forward to working closely with Tacoma Water and continuing to provide clean, safe and reliable drinking water for our residents.”