11/25/2011
Reed Hollinshead
ITD Communication
208-334-8881
reed.hollinshead@itd.idaho.gov
ITD nears completion of fish-friendly project near Lowman
BOISE COUNTY - "Chokepoint" is a term often heard in regard to transportation, but usually it's not referring to fish.
Because the opening was too narrow and too steep, a culvert 11 miles east of Lowman on Idaho 21 in Boise County was identified by the U.S. Forest Service as a physical barrier that inhibited access by fish and other aquatic species to Five Mile Creek on the upstream side of the culvert.
The Idaho Transportation Department's solution was to remove the 300-foot, 72-inch wide culvert and replace it with a 125-foot wide pre-stressed concrete girder bridge, opening up the entire Five Mile Creek watershed for use.
Click here for "before," "during" and "after" pictures of the work.
In mid-June a $1.2 million Forest Service-funded project began with ITD oversight and construction. The impeding culvert was removed and replaced with a short-span bridge that also provides wildlife in the area safe passage under the bridge. Since that time, the stream has been rehabilitated and re-routed.
The fish-passage project is scheduled to wrap up by early December. Crews will return in the spring to complete seeding, paving and roadway approaches, and other minor work.
“The culvert had long been a barrier, and now that it's gone, there is a wider range of habitat for the aquatic species, which contributes to the overall heath of the environment and the species that use it,” said ITD Southwest Idaho Environmental Planner Greg Vitley.
“It particularly benefits bull trout, a threatened and protected species that has lost habitat and the elements that contribute to its health due to past land use, management and natural disasters.”
Vitley explained that “Fish barriers are one of the contributing elements that have degraded bull trout habitat connectivity, which in turn has eliminated access to critical spawning and rearing habitat, limiting the reproduction of the species. Removing the culvert is a step in the right direction not only for bull trout but for other aquatic species that could inhabit the upstream area as well."
Scott Rudel, ITD southwest Idaho environmental planner/biologist, said the project “re-established the physical and biological connectivity of Five Mile Creek and the South Fork of the Payette River (upstream and downstream) where the road crosses over Five Mile Creek.”
“The bridge completely spans the Five Mile Creek channel and allows unrestricted water flow, thereby permitting the passage of fish, aquatic resources, and the transfer of river-bed material, sediment, and debris through an open-bottomed, free-flowing stream that did not exist before,” he added.