Levee repair and improvement planned in 2021

WAITSBURG—A little more than a year after the City of Waitsburg experienced a major flood event, repair efforts are still underway. Additional flood improvement projects are still being planned.

In 2005, the U.S. Army Corps of Engineers (USACE) decided to remove control of the levees surrounding Waitsburg from the inactive Waitsburg-Coppei Flood District. The flood control district had failed to address levee deficiencies found in yearly inspections. As a result, the City of Waitsburg was given maintenance responsibility over the town’s levee system.

At the time the city took over levee maintenance, City Administrator Randy Hinchliffe said that the banks were overgrown, with some areas inaccessible due to tree growth. Over the years, the city has worked to clear banks and create access to levees, a time-consuming process, according to Hinchliffe.

A section of the levee that flooded and sustained damage last year during the flood, runs east from the Preston Avenue bridge and past the Waitsburg Grange. It is considered an out-of-system levee, and maintenance falls to the landowners along the river. Hinchliffe said that the city has no access, rights, or easements to these levees, and it is hard to enforce repairs on private property.

According to Hinchliffe, most of the landowners along the out-of-system levee have moved earth to build up a makeshift riverbank since flooding last year. One property that holds rights to a section of the river where the bank was completely washed out, has not done any remedial work since the flood. Hinchliffe said he has big concerns about that section should we have another high water event, as it will offer little to no protection from high water. The landowner does not live in the area.

Since clearing the in-system levees, the city has maintained the minimally-acceptable rating required to remain in the USACE Rehabilitation and Inspection program.

Since the February 2020 flood, the city has focused on two projects: repairing a section of the flood-damaged riverbank near Willard Street and the levee downriver from the Main Street Bridge to the waste treatment plant. A small portion of that levee was missed during the initial repairs late last year and will be addressed in the coming year. A damaged siphon was also repaired last year near the Preston Avenue bridge.

Hinchliffe said minor repairs were made, after highwater events, to the Willard Street riverbank in past years, but the most recent flood event exposed old train trestles and gabion baskets (woven wire mesh filled with heavy rocks) making repairs more difficult. Heavy riprap was washed downstream last February and was eventually caught at the Preston Avenue bridge.

There are areas of concern upstream from Waitsburg, many in Columbia County, that cannot be addressed until the Hazard Mitigation Study, performed by the USACE. At this time, there is no finish date for the study, however, Hinchliffe is optimistic that it will be completed by mid-summer.

As city officials look deeper into the new year, flood repair and prevention is high priority, with lots of focus being placed on the Preston Avenue Bridge area. Years’ worth of blackberry bushes, heavy riprap, trees, and other debris have almost completely blocked two of the arches under the bridge and the debris must be removed to allow higher water volume to pass should another flood occur. The riverbed under the bridge is scheduled to be dredged to remove underwater debris and silt build-up.

Working on waterways and levee systems is not always easy. Hinchliffe said there are many studies and permits that must be completed before any work can be scheduled.

The Coppei River also has sections that have Hinchliffe concerned and the city has limited access to its banks- access is mostly around the Waitsburg Fairgrounds up to the Coppei Avenue Bridge at the south end of town.

Hinchliffe shared that Walla Walla County has addressed some of the issues upstream, near Meinburg Road, by placing rock and other materials along the bank. He said he was unsure if the repairs would hold, as the river has a longstanding history of flowing outside of its banks in the area.

The now-inactive flood control district built a small dike system along the Coppei in 2003, but it has not been maintained. This year, the city will clear trees and vegetation around the dike and reinforce the banks with rock.

The city will address issues at the Coppei Bridge on West 7th Street, by improving scoured beds and eroded banks and removing woody debris both upstream and downstream. Last year, the Coppei River broke behind West 7th and flowed through a field before it flowed back into the riverbed just before the bridge.

Efforts to make necessary repairs have been significantly delayed by the coronavirus pandemic, according to Hinchliffe. He said that it has been unusually difficult to contract companies to perform the necessary work.

At this point, Hinchliffe said that the city has accomplished a lot as far as repair goes, and he is confident that this is the most protection the city has been able to offer residents against flood events for many years, but he knows there is still plenty of work to come.