Lake Levels

Current Reservoir Levels

Important Update on Lake Tapps Reservoir Levels 

Cascade’s Lake Tapps Reservoir conveyance system project is underway. No water has been added to the reservoir since late August and residents may already be noticing lower water levels. Residents should take note of the unique conditions in their locations to decide when to remove boats from the reservoir, especially in shallow bays or coves. Some areas may become too shallow for some uses more quickly than others, and homeowners should watch the water levels and act accordingly.  

In August, Cascade filled the Lake Tapps Reservoir to its highest allowable level (approximately elevation 543 feet) and closed the project headgate for inspection and repair work on the facilities that make up the conveyance system to the reservoir. No water has been added to the reservoir since then (other than rainfall) and Cascade has minimized water released through the tailrace to keep the reservoir as full as possible through the end of the recreation season on September 30, while work is being carried out upstream. The project will improve the reliability and water quality of the water that flows through the conveyance system to the Lake Tapps Reservoir.

The reservoir will slowly drawdown between now and the end of October, with no added water coming into the system other than rainfall. Cascade will begin active fall drawdown on November 1 and will bring the reservoir level down to approximately 539 feet for the fall and winter.  This drawdown is necessary for the integrity and maintenance of the dikes and to ensure safety from wind, storm, and wave action during the winter months.

Residents can monitor overall reservoir water levels by clicking here.

Cascade maintains seasonal recreational water levels between elevation 541.5 feet and 543 feet from April 15 to September 30.  The 2022 spring refill is anticipated to begin in mid-February.

As a reminder, residents who wish to do any work on their property, such as bulkheads, docks, boatlifts, etc., must obtain all the appropriate, required permits and a Cascade license prior to beginning any work.  Further, residents should keep in mind as they do work on their property, especially bulkheads, that Cascade has the authority to raise reservoir levels to elevation 543′ under current water rights, so any new or modified bulkheads should be built to at least elevation 544′. Cascade raises the reservoir to 543′ once a year for a day or so as a reminder.

For information regarding licenses for project work click here.

USGS Links:

Lake Tapps Level Gage

White River Gage

General Reservoir Level Management

Cascade has owned and operated the Lake Tapps Reservoir since 2009. During that time, Cascade has managed lake levels in accordance with the provisions of the Lake Tapps Reservoir Water Rights, which incorporate relevant provisions from the 2009 Agreement regarding Lake Tapps between Cascade Water Alliance and the Lake Tapps Community and the 2008 White River Management Agreement between the Puyallup Tribe of Indians, the Muckleshoot Indian Tribe and Cascade Water Alliance.

The Water Rights and the agreements provide for Cascade to maintain recreational reservoir levels or normal full pool, between elevation 541.5′ and 543.0′ (gage height) from April 15 through Sept. 30.

Typical fall drawdown to a lake level of approximately elevation 538′ – 539′ is sufficient to protect the integrity of the Lake Tapps dikes and for any routine inspections. This minimizes the wear on the valves in the power house during fall drawdown and the risk of problems refilling the Lake Tapps Reservoir during periods of water shortage.

Specific dike or other maintenance projects will require Cascade to reduce the lake level in the fall and winter to approximately elevation 533′ to 535′ (some projects may require the level to be lower).