A plan to reconfigure the Port of Camas-Washougal’s levee system is expected to remove a section of the levee where some deficiencies have been noted by the U.S. Army Corps of Engineers.
Other deficiencies, such as rutting — impressions made by walkers, cyclists and horses — and severe mole burrows, will be repaired in 2018, according to Port of C-W Facilities Manager Jeramy Wilcox.
The levee reconfiguration — a $22 million habitat restoration and flood control project — will involve constructing two setback levees perpendicular to the Columbia River, north-south, at the same elevation as the current levee height — seven feet above the 500-year flood elevation.
A Corps of Engineers inspection in March 2010 said the levee, drainage structures and pump station, which comprise the Washougal Flood Damage Reduction Project, was intact and functional and has, overall, been well maintained.
“Some improvements to the condition of the levee should be made,” the report stated. “No levee safety issues were identified that pose an immediate threat to the levee functioning as authorized.”
Items that received an unsatisfactory rating included the presence of trees greater than two inches in diameter within the 15-foot-wide vegetation free zone, which extends outward from the levee toe.
The report mentioned the lack of video inspection of the Lawton Creek freshwater intake pipe, and the lack of clear responsibility for operation and maintenance of the State Highway 14 portion of the levee that constitutes the downstream tie into high ground.
Other deficiencies, described as less serious in the Corps report, received a minimally acceptable rating. The report mentioned the current operation and maintenance manuals and emergency action plans for the Washougal Flood Damage Reduction Project were out of date.
The report mentioned several non-permitted encroachments, such as utilities, buildings and guard rails, reduce the effectiveness of inspection and construction activities during flood stages, and bank erosion, near the levee toe, warrants active monitoring.
With the minimally acceptable rating, the Washougal Flood Damage Reduction system remains eligible for federal repair assistance if it is damaged by flooding, according to Wilcox.
He said the levee could have issues, if there is an earthquake — depending on the size of the earthquake.
High water can be a concern, according to Wilcox. In April 2017, there was flooding at Capt. William Clark Park and Steamboat Landing Park, in Washougal.
The reconfiguration of the Port of C-W’s levee system is expected to reduce flood risk, reconnect 912 acres of Columbia River floodplain and increase recreation opportunities at the Steigerwald Lake National Wildlife Refuge, according to information provided by the Lower Columbia Estuary Partnership.
The removal of 2.2 miles of the existing levee, constructed in 1965, would improve salmon habitat. Officials expect the reconfigured levee will help protect the Washougal wastewater treatment plant, located at 3900 SR-14, from flooding and reduce the amount of money the port pays to Clark Public Utilities for pumping excess water from Gibbons Creek.
Construction of the reconfiguration project is expected to begin in 2019 and continue for two years, according to Port of C-W Executive Director David Ripp.
Karim Delgado, a spokesman for the Portland District of the U.S. Army Corps of Engineers, said the risk associated with each levee system is based on the potential of that system to fail, plus the potential consequences of failure.
“By definition, risk can never be eliminated,” he said. “So long as there’s life or property that could be affected, there’s risk.”
Delgado said it would be reckless to suggest a levee system is immune to failure, no matter how well it’s maintained.
“We can never predict what dangers will come,” he said. “We can only be diligent in our work to prepare for them.”