As the Friday morning sun burned off clouds and mallards flew over the Newaukum River, it would be easy to forget the Chehalis tributary threatened to wash out the nearby Newaukum Valley Road less than a year ago.
“Losing this road would put a 10- to 20-minute increase on emergency responses in the valley,” said Lewis County Public Works Director Josh Metcalf.
Public Works identified that threat in March of 2021 and requested the Board of County Commissioners declare a state of emergency for the site. Because of this, the team was able to complete the project in under seven months.
For its “Newaukum Valley Road Bank Stabilization Project” the department was awarded project of the year by the American Public Works Association’s Washington chapter in the category of emergency projects for $5 million and under earlier this month.
Stabilizing a river bank is no simple task. Northwest Hydraulic Consultants had to come up with a creative design using jacks — named for the toy they resemble — constructed from 6 ton boulders and giant logs. The total weight of each jack came in between 6 and 10 tons. This project required 43 of them.
Another innovative technique used was a “bubble curtain,” which deters fish from swimming through the area while work is underway. Essentially, air is hosed upward through the river to create a wall of bubbles.
“The Newaukum is a heavy fish stream. They had to segregate the work zone from the fish, so they came up with the bubble curtain idea. It’s not standard use, we don’t typically use them here in Lewis County and they got it installed and it worked great,” Metcalf said.
Tunista Construction bid on the project at a rate 50% lower than the estimated cost. Metcalf said that initially seemed like a “red flag” but their team ended up being “outstanding. They came in here and they actually got it done quicker than they had even planned.”
He added that nearby property owners also played a role by being extremely cooperative, calling the entire project a team effort.
“Our own commissioners, our engineering team, our consultant contractor, everybody played part of that. The fact that we got it permitted and built in less than seven months, to me, is awesome. But the bigger deal is it just shows you that it's doable,” Metcalf said.
In November of 2021, the project had its first test from flooding. Then, as Lewis County Public Information Officer Austin Majors put it, the January flooding proved the methodology. The Newaukum in early January reached its all-time record high, and the log jacks remained in place, propping up the banks and adjacent road.
The criss-crossed design of the jacks also captures debris drifting down the river. This adds sustainability to the project as the river bank essentially builds itself back up.
“Just on a normal day, not flooding, the full force (of the river) was still going to continue to go into this weakening out of the river bank,” Majors said. “It got to a point where there was 30 feet of vertical wall there on the bank, which is not good.”
If the emergency steps had not been taken, the bank was about a foot away from making the road no longer safe to drive.
“We really should have the design team out here getting their picture. I mean, they really did all the work and made it happen,” Metcalf said. “Something like this is always on top of the regular work and then you’ve got to think outside the box, and then it's communication or it doesn't happen successfully. I’m extremely proud of our team. The work that they did in the timeline they did it in, it’s pretty amazing.”
