It may have seemed a long shot, replacing a culvert located under 20 feet of road fill at a sharp, downhill corner, without closing the road or disturbing the stream that flowed through the pipe.
But after several years of planning and preparation, and eight weeks of construction, a new culvert has re-connected Mill Creek in eastern Skamania County for struggling wild fish populations, reports Underwood Conservation District (UCD). The culvert was located under Lakeview Road, about a mile south of Northwestern Lake Park.
“We pulled together a lot of partners for this project,” says District Manager Tova Tillinghast. “Our contractor, James Dean Construction, performed admirably and built a great structure. Now, Mill Creek is open again to provide salmon, steelhead and other wild fish more than four miles of upstream habitat.”
James Dean Construction, of White Salmon, was selected as the project’s construction contractor in a public bidding process this past spring.
Called an open-bottom box culvert, the new 19.9-foot-wide structure is built with large precast cement blocks like enormous Legos, and functions similar to a low, wide bridge. It was designed by Tenneson Engineering Corporation of The Dalles, in partnership with Interfluve, Inc., of Hood River. In addition to opening fish passage, the new larger structure is designed to pass stream-flow during a 100-year flood, as well as any sediment or debris that might wash down.
James Dean finished most of the construction in September. There were a few bumps along the way – traffic delays in the early part of the construction period, soil that was softer than anticipated in one spot and harder than anticipated in others – but the project rolled along relatively smoothly, says Tillinghast.
This corner of Lakeview Road did not previously have a guard rail, but UCD has secured funding to pay for the installation of one, likely in mid-November. The roadway at this corner follows nearly the same geometry it did previously, but the road is wider now at the stream crossing. UCD will be planting native trees and shrubs along the streambanks and on the disturbed ground in early November.
The new structure replaces a four-foot-diameter corrugated steel pipe. Many undersized culverts, over time, scour plunge pools and erode streambeds, creating essentially steep manmade waterfalls. This hinders fish from swimming upstream and downstream, hampering or even cutting off fish-passage for returning steelhead and salmon species, and disconnecting fish populations.
The old Mill Creek culvert under Lakeview Road was determined to be a fish passage barrier due to the outfall drop as well as the slope of the culvert and velocity of water running through it. This is according to Washington Department of Fish & Wildlife criteria.
And while there is evidence that at least one salmon recently managed to swim up through the culvert, replacing it reconnects the stream for all fish – not just a few particularly athletic individuals – says Tillinghast. Mill Creek flows into the White Salmon River about five hundred yards downstream of the culvert.
UCD staff conducted a basin-wide fish passage inventory in 2009-2010, and the Mill Creek barrier under Lakeview Road ranked out as the highest-priority barrier to address, because of the length and quality of fish habitat upstream of the barrier as well as the significance of fish species accessing the creek.
Potential fish species benefiting from increased access to Mill Creek habitat include spring Chinook, Coho, summer and winter steelhead, Pacific lamprey, rainbow trout and possibly coastal cutthroat trout. Already, adult steelhead have been seen spawning in Mill Creek below the old culvert, according to Yakama Nation Fisheries biologist Joe Zendt. Now adult and juvenile salmon and steelhead will have greatly improved passage into Mill Creek.
“It is particularly important for juvenile fish as they now will be able to use several miles of high-quality rearing habitat. Mill Creek maintains year-round flow and perennial pool habitat, which is increasingly important for fish survival during dry summer months,” says Zendt.
Tillinghast added, “Though we were not involved in the removal of Condit Dam, now that it is removed, salmon and steelhead are recolonizing tributary streams like Mill Creek, and UCD is harnessing grant dollars to remove high-priority barriers to those streams.”
Tillinghast said, “Like farms and forests, wild fisheries are important resources for landowners and the larger community.”
UCD is one of 45 conservation districts in Washington. Conservation districts are non-regulatory, locally-organized special districts, like a library or hospital district, with the purpose of assisting landowners and communities in the enhancement, protection and restoration of natural resources, including habitat for important native species.
UCD staff work with Skamania County and western Klickitat County residents on a number of different natural resource projects. Conservation district staff can be found visiting with homeowners to advise and support work that reduces wildfire hazards, improves livestock management facilities, enhances forest land and addresses other needs in this area.
UCD secured funding for this project from several sources, including the Washington State Salmon Recovery Funding Board, the US Fish and Wildlife Service, the Pacific Coastal Salmon Recovery Fund via Yakama Nation Fisheries, and the Clark-Skamania Flyfishers club. Salmon Recovery Funding in the White Salmon River watershed is administered by Klickitat County’s Department of Natural Resources and local technical and citizen-review volunteers.
“We couldn’t do the work we do at UCD without local support and funding support, so we are very grateful for that,” says Tillinghast. “We especially want to thank the residents of the Lakeview Road area for their patience and flexibility during this project. Despite ‘a few bumps in the road,’ we now have a very good project completed, at no cost to local residents.”
To view the construction in fast-forward, time-lapse mode, view a 2-minute video at www.ucdwa.org