Water for fish and cities

Abundant supplies of water for people and salmon are at the heart of agreements between the Eastside's Cascade Water Alliance and two Indian tribes.

This is a win for all parties. Striking a balance between the needs of growing communities and the region's iconic salmon runs is an achievement.

For most of the 20th century, water was diverted from the White River to power a hydroelectric dam on Lake Tapps, south of Auburn. Salmon runs important to the Puyallup and Muckleshoot tribes suffered the consequences.

Power generation ceased in 2004. Since then, a consortium of eight Eastside cities and three water districts have looked to use Lake Tapps for future drinking-water supplies for their growing communities. The Cascade Water Alliance serves 370,000 residents and 22,000 businesses, nearly half of the retail water service in King County outside Seattle.

An agreement announced this month will keep more water in the river, while still providing water for homes and businesses through the 2060s.

The tribes challenged the alliance's application for a water permit from the state Department of Ecology, which is charged with monitoring all aspects of diversions from the White River.

In the early 1900s, only a trickle of water remained in the river after diversions began. Increased flows were mandated over time, but not so much the fish would notice. The settlement provides for water levels that mimic historic natural flows in summer and winter.

Water is a precious commodity and the region's water system needs long-term, coherent management. Bellevue, Kirkland, Redmond, other cities and water districts now buy water from Seattle and Tacoma. The Eastside has sought independence and control of its own supplies.

The deal, with state approval, moves Cascade Water Alliance a step closer toward that independence. Existing contracts with Seattle and Tacoma phase out starting in 2024. As the Eastside secures a new source, Seattle and Tacoma extend the horizon of their own supplies.

This settlement is important progress toward a much bigger opportunity.