Corps of Engineers repairs damaged Nooksack River levee

Repairs have begun on a ruined levee south of Ferndale that brought on flooding and evacuations of the Marietta area on Xmas early morning.

The 200-foot breach on Dec. 24, 2022, was likely induced by a combination of variables such as a king tide, cresting rivers and ice circulation prompted by freezing temperatures, in accordance to Kieth Rudie, acting chief of Unexpected emergency Administration in the Seattle District with the U.S. Army Corps of Engineers.

The breach was at a area of the levee alongside the Nooksack River just south of the Slater Street bridge.

The breach was 1st confirmed by associates of the Lummi Country, who observed it on a drone flyover, in accordance to Rudie. On Dec. 29, the Lummi Nation declared a state of crisis pursuing the levee breach, though a information launch from the Lummi Country reported it is possible the worst of the flooding has passed.

The river breached the exact same levee in a a little different place final 12 months, in accordance to Rudie. He estimates the expense to mend the levee will be a number of hundred thousand dollars. Repairs are scheduled to be accomplished later this 7 days.

The levee is designed of piled earth and rock, and is in essence an upgraded river bed. When the river overflowed and arrived in excess of the levee it harmed the levee, decreasing it by four to 6 feet. Maintenance crews are functioning to convey far more earth and rock to the levee, filling in the holes and rebuilding the levee to the original top.

“What took place here is that someday among 10 p.m. and midnight, Xmas eve, the ice in the river jammed up and released below (the levee). This is the (likely) end result of an ice flood burst, and the trees ended up barked from the ice flowing over the levee and what was remaining of the levee,” stated Gary Goodall, a former river and flood engineer for Whatcom County. “I have not noticed this in 40 a long time of performing on the river and currently being all-around the Nooksack. We have had ice two or a few situations, but not an ice jam debris flow. This is a when-in-a-vocation event.”

Goodall is retired, but however will come in to help when he is needed.

What manufactured this flood exclusive was the ice included. Not only did the river overtop and burst the levee, but the water was entire of ice, stripping the trees of bark and generating the flood even extra hazardous.

The precise time and cause of the river topping the levee is unidentified, in accordance to Rudie.

The river overtopping the levee made a scour hole, which triggered a breach in the levee. A scour hole takes place when falling water carves out a segment of earth, comparable to digging a hole in a flower bed with a yard hose. In this circumstance, the floodwaters from the river topped over the levee, and arrived crashing down on the other facet, digging a hole and breaching the levee.

The levee moves hundreds of toes parallel to the Nooksack River, to limit flooding. The Nooksack, like all rivers, twists and turns by the county. The damaged section of the levee arrived at a convert subsequent a very long straight duration of river, so the drinking water crashes into the levee at significant speeds.

There ended up also a number of unconfirmed experiences that the river was blocked by something, in accordance to Rudie. This seemed probable because the river gauge in Ferndale, a product applied to measure the height of the river, was demonstrating an maximize, but the river did not feel to be flowing. Goodall mentioned he was in the space, seeing the gauge as this happened.

“The notion of an ice dam would seem fair simply because the river rose extremely promptly in less than an hour’s time, and then the gauge dropped,” Rudie claimed. “Ultimately, what appears to have occurred is that the river did back up to a stage the place it overflowed.”