Johnson Creek Tributary

Technical Description:

• BridgeCor^® Structural Plate
• Span: 28-ft.
• Rise: 17-ft. 3-in.
• Length: 83 ft.

Located just 10 miles from Sekiu in Clallam County, Washington, Johnson Creek is a popular destination for fly fishing. When the existing structure on Hoko-Ozette Road over the creek was deemed a barrier to fish passage, it needed to be replaced. It was imperative that the new structure be fish friendly and bottomless in order to allow salmon to swim upstream and spawn. The project was sponsored by the North Olympic Salmon Coalition (NOSC) which "works to promote robust wild salmon stocks for families, fishers, and local economies by furthering habitat restoration and education on the North Olympic Peninsula."

After discussing options with Sargent Engineers, the project team decided that a 28' span x 17'-3" rise BridgeCor® Structural Plate, 83' in length, was the best solution for its cost savings and ability to be installed quickly within a short construction window before the next spawning season began. During the design phase, engineers from Contech Engineered Solutions assisted by providing Finite Element Analysis to properly gage the structure and size the cast-in-place foundations.

In order to meet the tight deadline, the county purchased the structure prior to bidding. The order was placed the last week of May and arrived on site the first week of August. Prior to the structure's arrival, Interwest had completed the deep excavation, established a stream bypass and cast the reinforced concrete footings for the structure's foundation. Since the site is remote, creating a detour route was impossible, so instead, they also had to construct a temporary bypass road.

Once the BridgeCor structure arrived on site, it was assembled and installed in less than two weeks. The structure was then backfilled with the prescribed material and compacted to the required level. Mechanically stabilized earth (MSE) headwalls were constructed at each end as the backfilling proceeded. Above the wire wall headwalls, Interwest constructed steep embankment slopes and planted vegetation. In the end, the project was completed within the contract time frame and provided a great solution for the site. Project partners Clallam County, Sargent Engineers and NOSC were pleased with the outcome.

“I was amazed at the relatively simple and speedy install for a crossing of this span,” concluded Kevin Johnson, Project Manager of NOSC. "It was an excellent fit for this application. Our excavation and backfill effort was considerable on this project and ate most of the schedule so having the BridgeCor product go in quickly was one of the keys to our success."

Funding for this project was provided by the county and the Brian Abbott Fish Barrier Removal Board, a grant program established in 2014 "to identify and remove impediments to salmon and steelhead migration."

Technical Description:

• BridgeCor^® Structural Plate
• Span: 28-ft.
• Rise: 17-ft. 3-in.
• Length: 83 ft.