Culvert replacement set along SR 4
March 12, 2014
Completion of a wetland habitat improvement project will impact traffic on S4 this summer.
A contractor will replace two culverts under the highway in the vicinity of Milepost 34.
Construction will start in July and finish in August, according to Washington State Department of Transportation (WSDOT) engineer Paul Harrison. The contractor will close the highway to one lane traffic which will be controlled by flaggers during working hours and by traffic signals in off hours.
The highway department will team with Columbia Land Trust and the state Department of Fish and Wildlife on the habitat improvement project.
The land trust has purchased over 290 acres lying east of SR 4 and plans to turn the land into wetland habitat that can be used by juvenile salmonids. The land was logged in the 1960's and hasn't been used since then.
In the first phase of the restoration, a contractor decommissioned the logging road leading into the middle of the parcel, which is partially bordered on the northern and eastern sides by the Elochoman River, and removed culverts and fill to open old tidal channels.
Workers also planted native trees and shrubs in the area and removed a lid on a tidegate at Milepost 34.09.
In 2014, workers will remove the two tidegates under SR 4, which are barriers to fish passage, replace them with four-sided box culverts, one 20'x12' and the second 12'x8'. The existing culverts are round with 48 and 42-inch diameters, respectively.
The new culverts will be lower in the ground and improve drainage and tidal flow in the area, said WDFW Restoration Division Manager David Price.
Price and Harrison reviewed the project with the Wahkiakum County board of commissioners on Tuesday; commissioners had questions, comments and a desire to work with the agencies on similar projects.
Commissioner Mike Backman asked how much benefit the project could have for salmon runs.
"That's difficult to quantify," Price responded. "This is a very good project, but we can't predict returns."
Commission Chair Dan Cothren commented that there is much good habitat that fish can't reach because of bad culverts. The forest industry has done a good job cleaning up habitat, "but the fish can't get up there," he said.
County Public Works Director Pete Ringen said the county had inherited a lot of bad culverts when the state had ceded the former state highways that are now the Elochoman and Altoona/Pillar Rock roads, and contemporary design standards make them very expensive to replace.
"We don't have the revenue stream to do that kind of replacement," Ringen said.
Commissioner Blair Brady suggested that if projects incorporated smaller culverts than the new standards incorporate, funding for replacing culverts could go much further.
Cothren said that the requirements on counties to replace culverts presents an unmanageable financial burden that counties can't handle on their own.
"We can't get it done," he said. "We need partners."
"I completely agree," Price responded. "I'd be happy to work with you."
Price said his department lacks funds to do all the projects it needs to do, he said. Thus, the department partners with organizations like the land trust, as in the current project. Together, they've gone after habitat restoration funding offered by the Bonneville Power Administration.
Price added that the large box culverts chosen for the Elochoman project should have low maintenance costs over the long term. They're larger than the old culverts so that they mimic stream flow and are conducive to fish passage.
"These are based on stream simulations; that's why they're so big," he said.