Mill Creek levees repaired after damage from 2020 Flood

By Hannah MitchellApril 1, 2021

WALLA WALLA, Wash. – The U.S. Army Corps of Engineers’ Walla Walla District completed repairs to sections of the Mill Creek Levee System that were damaged during the February 2020 flooding.

This was a partnership project with the levee sponsor, the Mill Creek Flood Control Zone District, operated by Walla Walla County.

Mill Creek had a record flood event in early February 2020, causing extensive erosion damage throughout both banks of the levee system. These levees were built using gabions (wire-bound cells filled with cobbles) as armor protecting the riverside slopes of the levees. During the flood, some of the gabions, along with portions of the riprap revetments, were damaged and had to be reconstructed.

On Dec. 1, 2020, the Corps awarded a contract to TDX Power Services to rehabilitate more than eighty damage sites along the federal portion of the Mill Creek Levees. The total value of the contract was just over $2 million dollars. The repairs will provide increased protection for over $3 billion of property in the area around the Mill Creek Levee System.

The Corps’ Mill Creek General Investigation Feasibility Study is ongoing and will be completed this year. The recommended plan includes additional levee improvements in six locations between the Mill Creek Diversion Dam and Gose Street. Other elements of the recommended plan include three repairs in the concrete channel and a change to project operations.

The Mill Creek Flood Control Project was completed in 1942 and includes levees along the improved Mill Creek channel to provide flood protection for the City of Walla Walla.

For more information about the Mill Creek Levee System, please contact Walla Walla County Public Works at (509) 524-2710.