Water storage at Howard Hanson Dam for Tacoma Water’s municipal and industrial water supply will reach an elevation of 1,167 feet by June 1, significantly increasing its water supply resources, according to the Seattle District, U.S. Army Corps of Engineers.
"Howard Hanson Dam’s new water storage capabilities will nearly double the water supply the dam was previously providing," said Col. Michael McCormick, commander of the district.
Traditionally, during the summer months before the implementation of this new additional water supply project, the highest reservoir pool elevation was 1,147 feet.
The reservoir will be expanded to accommodate a total of 50,000 acre-feet of water, increasing its capacity by 20,000 acre-feet of water.
The Corps began slowly allowing water levels to rise within the dam’s reservoir in March. Any impact from the higher reservoir level will be within the closed watershed property area around the dam. Populations down stream of the dam will see little if any change.
The Corps operates the Howard Hanson Dam project, which provides flood damage reduction to the area as well as additional water supply to Pierce and South King counties and eco-system restoration.
Additionally, three-fifths of the reservoir’s supply will be used to augment downstream supplies of water to help endangered species of fish, including Chinook and steelhead. Project managers believe that the regulated downstream flows will aid spawning and other life cycle events for the fish.
Throughout the reservoir fill, as with all project functions, the Corps will constantly monitor the operations of the facility.
"Any time you implement a new process at a dam, it’s normal to be very conservative, careful and to keep a watchful eye," McCormick said. "Howard Hanson Dam is a great example
of how environmental sustainability for both people and fish is possible. We’re working to ensure that continues."
More details and history about Howard Hanson Dam can be found at
This site is 508 Compliant
