Lake Tapps, WA – Cascade Water Alliance has announced the 2025 Lake Tapps Reservoir water levels and fall drawdown plan. Due to a construction project at the White River diversion point, starting no earlier than September 2, no additional water will be capable of being added to the reservoir. Cascade will minimize water released from the tailrace to allow the reservoir to stay as full as possible during the construction period. Cascade has held water levels slightly higher than usual this summer in anticipation of this event. The project will improve the reliability and water quality of the water that flows through the conveyance system to the Lake Tapps Reservoir.
The planned water levels will allow the reservoir to stay as full as possible through the end of the recreation season on September 30, while construction work is being carried out upstream of the reservoir and no additional water is capable of being added.
Starting November 1, Cascade will actively drawdown reservoir levels to approximately 539 feet for the fall and winter. This allows Cascade to perform necessary maintenance on the dikes and ensures safety from wind, storm, and wave action during the winter months.
Residents should watch reservoir levels and make appropriate decisions regarding removing boats and other property from the water.
Cascade maintains seasonal recreational water levels between elevation 541.5 feet and 543 feet from April 15 to September 30. The 2026 spring refill is anticipated to begin in mid-February.
If residents are planning work on their property, this is a good time to obtain 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 feet under current water rights, so any new or modified bulkheads should be built with the consideration that the reservoir level will be up to 543 feet.
For more information about Cascade and the Lake Tapps Reservoir, visit cascadewater.org, and for information regarding licenses for project work, visit cascadewater.org/lake_tapps_licenses_and_permits.php