Delay in Re-opening Lake Tapps

Drought conditions delay re-opening of Lake Tapps

Photo of Lake Tapps

May 1, 2015  With this past winter’s lack of any significant snowpack buildup in the Cascade Mountains, flows in the White River (east Pierce County) are substantially lower than usual.  As a result, it won’t be possible for Lake Tapps to be ready for use by Memorial Day.  The mechanisms to fill it in time for the long weekend are all functioning as they should – but without nature’s cooperation, even these best laid plans are stalled out.

On April 23 Cascade Water Alliance (CWA) announced that there would not be enough water available from the White River to completely fill the reservoir by May 23, the start of Memorial Day weekend.  They will continue to add as much water as is available, but cannot predict right now when Lake Tapps will be opened for summer recreational activities.

CWA is limited as to how much water it can withdraw from the White River.  By state law, there must be certain amounts of water left in stream for fish, wildlife, recreation and the natural environment.  And the White River is experiencing all-time low flows, the lowest flows of record in the past 50 years.

Even with these constraints, CWA has already put 5.5 billion gallons of water into the lake, and continues to add about 50 million gallons per day.  But even with this effort, they cannot overcome this past winter’s lack of rain and minimal snowpack.

The Lake Tapps Reservoir is normally drained every winter and refilled for summer.  CWA reopened the Lake Tapps Reservoir System in March, after being down for more than seven months for significant repairs, maintenance and improvement to the 100-plus year-old system.  CWA began refilling Lake Tapps on March 13, as planned.

Background on Lake Tapps and its purchase by Cascade Water Alliance

Lake Tapps Reservoir was completed in 1911 by Puget Sound Energy (PSE) for hydroelectric power. It is now owned and operated by the Cascade Water Alliance for eventual municipal water supply.

PSE stopped hydropower operation in 2004 because of the costs of project operation associated with a Federal Energy Regulatory Commission hydropower license and sold the project to the Cascade Water Alliance in 2009.

In 2010, the Dept. of Ecology (Ecology) issued to CWA four interrelated water rights and one water right change.  The water rights package completed a multi-year project to propose and develop a regional water supply system to meet the Central Puget Sound’s long-term municipal needs.  Lake Tapps is expected to provide a drinking water supply for nearly 400,000 residents in Bellevue, Redmond, Kirkland, Issaquah, Tukwila, the Covington Water District, the Sammamish Plateau Water and Sewer District and the Skyway Water and Sewer District.

The water rights package approved by Ecology allows CWA to store water in the Lake Tapps Reservoir, divert water from the White River into Lake Tapps to supply water for the Water Supply Project, and withdraw water from Lake Tapps for municipal water supply purposes.  It is expected that the project will take 50 years to fully develop and gives CWA the authority to take an average of 48 million gallons of lake water a day (equivalent to a football field covered with water 147 feet deep) for public use.

Part of CWA’s agreement with Ecology was that Lake Tapps would remain filled for the benefit of homeowners and recreational users.  The agreement also included a sizeable trust water donation, discussed below.

The Cascade Project consists of a diversion dam on the White River at the town of Buckley, an 8-mile flow line, an off channel storage reservoir (Lake Tapps) and a powerhouse and tailrace canal that enters the White River below Auburn.  CWA, which has agreements with local tribes, cities and homeowners to ensure water for fish and people, has completed significant improvements to the entire system.

Largest trust donation in recent memory

On January 17, 2015, CWA made a permanent donation of 684, 571 feet of water (equivalent to a football field covered with water 130 miles deep) to the state’s Trust Water Rights Program.  The water will stay in-stream for the preservation of instream flows and to protect fish habitat in a stretch of the White River that flows through the Muckleshoot Tribal Reservation.

The largest in recent memory to the trust water program, the donation completes the agreement CWA made in 2010 to donate a portion of the water rights it acquired in the purchase of Lake Tapps from Puget Sound Energy.

In addition to its permanent trust water donation, CWA donated another 154,751 acre feet of water (equivalent to an additional football field covered with water 29 miles deep) to the Temporary Trust water rights program until 2034.  The donated water stays in the White River for the benefit of fish, wildlife, recreation and the natural environment. Ecology has agreed not to approve or issue new water right permits for 20.7 miles of the Reservation Reach of the river.

Report of Examination – Ecology’s decision documents

On September 15, 2010, Ecology approved and posted the final Lake Tapps Public Water Supply Project reports of exams.  The final water rights decisions and related appendices are posted below:

Related Information Sources


Lake Tapps Water Supply Project
Southwest Regional Office
Department of Ecology
PO Box 47775
Olympia WA  98504-7775
Phone 360-407-6859

Cascade Water Alliance
520 112th Ave. SE #400
Bellevue, WA  98004
Phone: 425-453-0930

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