Posted on October 21, 2024
SEATTLE — U.S. Army Corps of Engineers officials awarded the Howard A. Hanson Dam Additional Water Storage Fish Passage Facility Project contract to Flatiron-Aecon Joint Venture on October 16th. The total contract price is $657 million.
The contract method is innovative and allows collaboration between designers and the contractor during project’s design phase.
“We are excited to support salmon and Orca recovery with our tribal partners, federal and state agencies, and our non-federal sponsor Tacoma Public Utilities to ensure completion of this downstream fish passage facility and support the regional water supply,” said USACE Seattle District Commander Col. Kathryn Sanborn.
Tacoma Public Utilities has already completed an upstream fish passage facility that is ready for operation. Once USACE’s downstream facility is operational, the two facilities will restore the biological connection of the upper watershed (45% of total area) to the lower watershed via salmon migration.
The project will provide over 100 miles of high-quality river and tributary habitat. The project will increase the ability of Endangered Species Act – listed Chinook salmon to access substantially more spawning and rearing area – 221 square miles of undeveloped watershed.
Howard A. Hanson Dam is an earthen dam on the Green River, 35 miles southeast of Seattle.
Howard Hanson Dam was built to protect the people and infrastructure of the Green River Valley from historical catastrophic flooding. The dam has prevented an estimated $23 billion in flood damage since its completion in 1962. The dam includes other benefits such as providing clean drinking water to the people of Tacoma, Covington, and other areas, fish conservation and ecosystem restoration.
This will be the second Seattle District fish passage facility to be constructed in recent years in the area. The new Mud Mountain Dam upstream fish passage facility, near Buckley, Washington, on the White River experienced a record-breaking year in 2023.
“In collaboration with our tribal partners, the Corps of Engineers successfully passed 1.4 million fish in 2023 at the Mud Mountain Dam facility,” said Sanborn.
A rendering of the Howard A. Hanson Fish Passage Facility.
Howard A. Hanson Dam, King County, Washington.
