Lake Tapps Reservoir Drawdown Schedule

Cascade Water Alliance and the Lake Tapps Community Council today announced the winter 2017/2018 drawdown schedule for Lake Tapps, and noted the long-term look at future lake levels.

Initially, the lake drawdown will begin in mid to late October, lowering the lake level to approximately 539 feet, through December 2017.

Cascade will then draw down Lake Tapps to 530 feet beginning Jan. 2, 2018, to accommodate several dike stability issues as well as projects for Pierce County and Bonnie Lake.  The reservoir will be down until the fill begins around mid- to late February.

Projects expected to be addressed include:

  • Support for the integrity of Dikes 3, 4, 11 and 13,
  • Inspection of the Island 21 Bridge supports,
  • Replacing the Lake Tapps gauge shack piling and decking,
  • New pilings at the Pierce County boat dock, and
  • Fixing supports for Bonney Lake’s Vandermark Bridge.

In addition, the US Army Corps of Engineers is scheduled to award and contract for construction of the Mud Mountain Dam Fish Passage Project in spring 2018. Construction is scheduled to begin in 2018 and could last up to four years, during which time Cascade will ONLY bring the reservoir down to approximately 538 to 539 feet.  Residents are urged to take this opportunity to do work on their property during this time, as there will be no further drawdowns for four years.

However, residents who wish to do any work during this draw down period must act now to obtain all the necessary permits from the City of Bonney Lake, Pierce County, and the Department of Fish and Wildlife (if appropriate) and get a license from Cascade.  These documents must be obtained prior to beginning of construction.  For more information on Cascade’s licenses visit or email

Lake Tapps is a recreational gem of the region, especially for the homeowners who live near its shore.  But it’s also a working reservoir owned and operated to eventually provide municipal drinking water to members of the Cascade Water Alliance.  Keeping Lake Tapps clean and healthy is up to everyone who enjoys the lake today and into the future.  Residents are advised that nutrients from failing septic tanks and nutrients from fertilizers and from runoff feed vegetation in the reservoir and can result in excessive algae, toxic algae blooms, reduced water clarity, and stress on fish and wildlife.

Cascade purchased the 100-plus year old White River system and Lake Tapps Reservoir from Puget Sound Energy in 2009. Since then, Cascade has invested tens of millions of dollars to keep the reservoir infrastructure reliable and the waters healthy with milfoil control.

Cascade needs the help of residents to keep Lake Tapps clean and healthy!