Story

The Little Traverse Band of Odawa Indians (LTBOI) received grant funding from the United States Natural Resources Conservation Service for the stream crossing replacement at Wycamp Creek under N Lake Shore Drive, near Cross Village in the Tunnel of Trees, Michigan. The LTBOI passed the funding to the Emmet County Road Commission (ECRC) as the Owner of the crossing to complete the work. GFA was selected by the ECRC to perform the engineering design and construction management of the project. The existing stream crossing consisted of a perched 72" diameter corrugated metal pipe that was significantly undersized for the 22.5 square mile drainage area that it was conveying. The undersized culvert restricted stream flows upstream of the crossing and created turbulent conditions downstream of the crossing. These conditions prohibited the passage of aquatic organisms and migratory fish species, such as salmon, from Lake Michigan from moving upstream to native spawning grounds.

GFA performed a topographic and hydraulic survey of the project site and completed a hydraulic analysis using HEC-RAS and a Type, Span & Length (TS&L) analysis to determine the most suitable stream crossing replacement option for the site. If was determined that due to the road geometry and underlying soils, along with a desire to restore the stream to its original streambed, that a timber bridge structure was the best option for the site. The timber bridge allowed for the restoration of the native stream bottom to eliminate any fish passage barriers while providing the require bankfull width to pass the streams significant seasonal flows, as well as allowed for N Lake Shore Drive to be raised 5 feet to correct vertical road geometry. In August of 2024 John Henry Excavating completed the construction of the 62 foot long 3 span timber bridge. GFA provided full construction testing, inspection and project management in accordance with NRCS requirements during construction. Key project components include:

• Raising the existing road grade 5' to correct vertical road geometry and provide a safer travel way in the Tunnel of Trees
• 62' - 3 span timber bridge
• 300' of guardrail
• Riprap
• Instream material to restore the native stream bottom

The final timber bridge restores connectivity in Wycamp Creek to allow for unhindered passage of salmonoids and aquatic organisms to move upstream of the N Lake Shore Drive road crossing from Lake Michigan. These fish and organisms have been unable to reach their native spawning waters for decades.