Mill Creek Flood Control Project repair approval signed into place

The Mill Creek Project was put into place after the worst flood in Walla Walla’s history, in 1931. It’s played its role in minimizing flooding damages, but it’s in need of repairs after decades servicing Walla Walla.

WALLA WALLA, Wash. — The Mill Creek Project was authorized by congress after the worst flood in Walla Walla history in 1931. With it, a coalition of City of Walla Walla leaders created a reservoir, a diversion dam and a series of canals to manipulate flood waters away from the city center.

At Monday afternoon’s Walla Walla County Commissioners meeting, the U.S. Army Corps of Engineers and Walla Walla County came together to finalize a partnership that will maintain and repair some of the project that was built decades ago.

The infrastructure has played its role in minimizing damages, but it’s in need of repairs after 80 years of servicing Walla Walla. The two organizations signed a $10 million project into place at this meeting.

It’s something both have been waiting a long time to get into place.

“It’s a big deal moving forward,” said Lt. Col. ShaiLin KingSlack, with the U.S. Army Corps of Engineers.

They said getting funding and approval for the repairs is a process that’s been in the making for 10 years, if not longer.

“We’re in the designing phase, and that’ll be for about a year or two,” said Lt. Col. KingSlack. They then go on to award a contract in May of 2024, and begin construction in June. She said the construction should be complete at the end of 2025.

In the 90+ years following the worst flood Walla Walla had ever seen, it’s held up strong.

“It consolidated the flow that’s coming from Mill Creek, from the mountains, into a channel,” explained Tony Garcia, the Public Works Director for Walla Walla County, as well as a county engineer. “As opposed to in the 30s, where basically just all flooded and just fanned out throughout downtown Walla Walla.”

One of the main things they will be improving is heightening half a dozen levies by less than two and a half feet each. This will increase the capacity to hold water. They will also repair a 300-foot section of concrete wall, remove a damaged ceiling in the tunnel section and repair the supporting pilings in the tunnel.

“This system protects over 27,000 people, and over $7 billion in property,” said Garcia.

This project looks out for all of downtown, to keep it safe from disastrous floods. Tony Garcia said Walla Walla sees major floods every 20 to 30 years.

“It acted well in the 2020 floods, so we want to have reliability for 50 plus years,” said Garcia.

This $10 million project is 65% federally paid, and 35% locally paid, to get Walla Walla canals and water systems the reliability it needs for the next 50 years and beyond.

RELATED: 1940s Mill Creek Project helped divert water from downtown Walla Walla during historic 2020 flooding