North Bank Ln. Infrastructure Upgrades for Fish Passage & Community Resiliency

The North Bank Lane (NBL) Infrastructure Upgrades for Fish Passage & Community Resiliency project is an integral component to the Beaver Hill Wetland Reserve Restoration project. NBL is a Coos County managed road and is a major thoroughfare for local ranchers, timber hauling trucks, and homes between the communities of Bandon and Coquille, OR. The Beaver Hill Wetland is characterized by an invasive reed canary grass monoculture with a deeply incised channel, informally named Leslie Creek, running between a private access road (though an undersized 36” culvert) and NBL through two 12’x8’ corrugated steel arch culverts before reaching the Coquille River. Both the private access road and county road culverts are creating hydrologic constrictions to the tidal wetland, restricts fish access to rearing habitat, and simultaneously are of concern for community use should the undersized infrastructure fail during a volatile storm event. This project will produce designs to replace the undersized NBL culverts with at least a 45’ bridge, designs for the private access road, and provide for additional cultural resource investigations for our recently identified fill spoil sites and upland tree harvest locations (where the wood will be donated to the upcoming wetland restoration activities). This project will also allow CoqWA staff to oversee designs, develop a robust planting plan, and begin the complex permitting process. CoqWA will continue to partner with CIT, the Leslie Family, Coos County Rd. Department, ODFW, USFWS, and NRCS among other interested restoration practitioners to develop a suite of actions to reach our goals.

Historically coho and Chinook salmon juveniles as well as cutthroat trout and other species extensively used these tidal wetlands. With the high level of riparian canopy cover shading the channel network and strong tributary cold-water input, modeling has suggested that water temperatures and dissolved oxygen levels were satisfactory for year-round salmonid rearing. Prior to extensive European settlement, peak coho salmon abundance has been estimated at 412,000 returning adults (Lawson et al. 2007). This project will benefit salmon, steelhead and other native fish by creating designs to restore fish access to critical slow-water rearing habitat within the Leslie Creek sub-basin directly connected to the Coquille River. Studies have shown smolt growth rates are often 1.5-2.0 times greater for off-channel and tidal wetland habitats compared to stream locations (Nickelson. 2011). Additionally, it is estimated that these types of habitats were capable of rearing enough coho juveniles to produce 11-17 returning coho adults for every acre of high functioning floodplain wetland (Nickelson 2007). Accordingly, the tidal wetland habitat within the Leslie floodplain will have the capacity to annually produce 385 to 595 returning adult coho. Moreover, upper valleys of this subwatershed is anticipated to be able to provide adequate summer rearing temperatures for salmonids, critical refugia for juveniles to have access to the main-stem Coquille River when it becomes lethal in the summer due to rising water temperature. This project builds on several tideland projects undertaken in the Coquille Valley to restore floodplain and off channel habitat connectivity including the 1,700 acre Winter Lake Restoration Project (completed 2018), the 270 acre Seestrom Tidelands Restoration Project (completed 2022), the 490 acre Coaledo Drainage District Project (projected completion 2024), and the S.F. Coquille River Off-Channel Refugia Project (funding pending). Recent monitoring in the Lower Coquille conducted by CoqWA and ODFW (OWEB# 220-2057) indicates that juvenile coho extensively use these off-channel habitats and migrate between sites. Coho have been seen migrating between project sites as far as 7 river miles apart and residing in these sites off the mainstem Coquille for days or weeks at a time. This project is also protected in a NRCS easement, providing habitat for coho and other salmonids in perpetuity.