Cascade Water Alliance secures drinking water supply
October 5, 2010
The state Department of Ecology has OK’d a water-rights package for a future drinking water source for Issaquah residents.
The approval grants Cascade Water Alliance the authority to use a portion of the water in Lake Tapps for drinking water and, at the same time, guarantees water levels to maintain summer recreation at the popular Pierce County lake.
Department of Ecology Director Ted Sturdevant announced the agreement Sept. 16.
Formed in 1999 and headquartered in Bellevue, the alliance supplies water to more than 370,000 county residents and 22,000 businesses — or nearly 50 percent of retail water sales in King County outside of Seattle. The regional group includes the Sammamish Plateau Water and Sewer District, Issaquah, Bellevue and other Eastside and South King County cities and water districts.
The decision completes a decadelong effort to keep Lake Tapps from drying up. Alliance leaders do not plan to develop the lake as a regional water supply for decades. Before the supply starts to flow north to customers, the alliance must build water treatment and delivery systems.
The lake is a reservoir created in 1911 as part of a hydroelectric project on the White River. In 1999, Puget Sound Energy said the system had become too difficult to maintain.
Concerns arose among Lake Tapps homeowners and users about maintaining lake levels for boating, swimming and other activities.
PSE ended hydroelectric operations at Lake Tapps in 2004. The alliance purchased the lake from the utility in December 2009.
The agreement allows the alliance to divert up to 48 million gallons of water daily from Lake Tapps. Officials agreed to prioritize White River flows and summer lake levels in Lake Tapps before taking water for customers.
The process to secure the water rights required environmental scrutiny and negotiations among the alliance, the Muckleshoot and Puyallup tribes, a Lake Tapps community group and neighboring cities.
“The work to decide who gets to use the public’s water is some of the most difficult we face at Ecology,” Sturdevant said in a statement. “I believe we’ve struck the right balance with this decision. The key interests of each party have been preserved, reflecting the art of compromise necessary for good water decisions. It’s an approach we could use more of to ensure we have a water-smart future for Washington.”