Bonner County, ID

JAS provided hydraulic and civil engineering design, alternative analysis, contract document preparation, and construction oversight for Soldier Creek crossing at Cavanaugh Bay Road in Bonner County. Before construction, the crossing consisted of wooden culvert structures which had become out of alignment and showed signs of failure. The project was a high priority due to the fact that Cavanaugh Bay Road is the only paved access for residents located on the east side of Priest Lake, north of Soldier Creek.

JAS studied surrounding drainage basins and applied hydrologic and hydraulic analysis to create a stream model of Soldier Creek at the county road crossing. The resulting design storm flow rates for the creek were calculated to be approximately 2,400 cubic feet per second. The chosen structure to handle flow capacity was a 26-foot by 13-foot structural plate arch culvert with cast-in-place concrete headwalls and wing walls.

Regulatory agencies that JAS frequently contacted and assisted our client with permitting for this project included the Idaho Department of Water Resources, Idaho Department of Lands, US Army Corps of Engineers, and US Fish and Wildlife Service.