Located on National Forest Lands, two existing corrugated metal pipe structures were deteriorating and close to failing. Beaver activity in the area often restricted water flow causing the roadways to overtop suddenly in the spring due to runoff from the snow melt. Aquatic passage was also questionable so, as a replacement structure, an open bottom option was necessary to provide fish passage while also discouraging beavers.
Since the U.S. Forest Service (USFS) had successfully utilized products from Contech Engineered Solutions in the past in similar installations with excellent results, they decided that Aluminum Box Culverts (ALBC) were again the best solution.
In order to accommodate the contracting process and ensure installation was timed to minimize traffic and public access disruption, the USFS opted to purchase and furnish the structures up front.
A 12’-5” x 7’-4” ALBC, 40’ in length, was installed on Splains Gulch Road while a 11’-4” x 7’-2” ALBC, 32’-6” in length, was installed on Kebler Wagon Trailhead Road. ALBC’s were selected for ease of installation, unit cost, sizing and function. During the construction phase of the project, a hydraulic excavator was primarily utilized to excavate and place earthen materials and rock, and then lift and set the ALBC components into place.
“We like Contech’s structures,” stated Brent Scarbrough,Vice President of Frontier Environmental Services. “They are easy to assemble and install.” George Goehl, Civil Engineering Technician with USFS added, “From USFS’ s standpoint, they provide a solid value while meeting aquatic (and some terrestrial) organism passage needs and are much less costly to maintain compared to conventional culverts.”