Cascade Water Alliance previously announced the Lake Tapps Reservoir fall water levels and drawdown plan on August 18. Cascade held reservoir levels higher than normal this summer due to a construction project at the White River diversion point, and no additional water is capable of being added to the reservoir as of September 3. The project will improve the reliability and water quality of the water that flows through the conveyance system to the reservoir.
Due to the continued dry and warm weather conditions, reservoir levels are dropping. Residents should watch levels for the rest of September and October and make appropriate decisions regarding watercraft and other property. Cascade recommends that residents remove their boats from the water at the latest by mid-October, but keep in mind that specific situations may vary and require action before that date.
Cascade will begin the active fall drawdown on November 1 and will bring the reservoir level down from its current approximately 542.3 feet elevation to approximately 539 feet elevation 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.
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.
For more information about Cascade and Lake Tapps visit cascadewater.org, and for information regarding licenses for project work visit cascadewater.org/lake_tapps_licenses_and_permits.php