Coquille Subbasin Plan Phase III

The Coquille Subbasin Plan Phase III or the Cochran Ranch Project, was successful in many ways. Overwintering habitat access for Oregon Coast Coho was improved, water quality was improved through riparian planting and fencing, collaboration between many partners- landowner, Oregon Department of Fish and Wildlife, and Coquille Watershed Association- was successful. This project lasted longer than intended, 15 months longer, for a couple reasons. Permitting through NOAA (and the writing of the biological assessment/opinion) and Army Corps of Engineers took well over two years to obtain. The Coquille Watershed Association (who was the sub-contractor for the project) went through staffing shortages (staff passed away) and staffing changes. The Coquille Indian Tribes Natural Resources Department also went through staffing changes. All of these things combined to delaying the project and portions of Site 2 not being completed.

Site 1 improved fish passage by replacing a 36” top-hinged steel door tidegate and culvert, with a 72” side hinged tidegate with Muted Tidal Regulator (MTR) and culvert to improve water and fish passage. Following tidegate installation, contractor Tom Wheeler re-meandered historically straightened drainages and streams that had been silting in over the past decades. The re-meandered channels will restore and improve fish habitat by developing winter refuge/off-channel habitat. Large woody debris was also placed in the re-meandered channels. Mostly by penciling or burring the top of the log to allow the rootwad to be within the channel. The scope of work was finalized with the planting of native species along both sides of new stream channel (1.1 miles), four acres of wetland planted with native stock, as well as a livestock exclusion fencing and two improved livestock crossing areas.

Site 2 was modified from the original plans to accommodate wetland needs, permitting delays and unforeseen costs. This site has been limited to briar and debris clearing to allow the native plantings to take hold, which coincided with the Elk habitat restoration project, and planting of native species along both sides of new stream channel (1.4 miles), six acres of wetland planted with native stock. Additional work would have included further channel meandering, large woody debris placement, an additional wetland complex, with fencing and more planting. Costs associated with this site remained close to the same due to the delay in getting permitting; sub-contractor prices increased with the delay in time.

The project will create coho over-wintering habitat and improved migration and wintering habitat for numerous species of waterfowl and shorebirds. Historically there was an estimated 25,000 acres of vegetated wetlands in the bottom-lands of the lower Coquille River (Historical Reconstruction of the Coquille River and Surrounding Landscapes, 1997, p. 3.2-18). As of 2007, only 3-4% of tidal and freshwater marshes remain within the Coquille Watershed (Coquille River Subbasin Plan, 2007, p. 99). Historically the lower Coquille River was surrounded by wooded bottom-land hardwoods which trapped and deposited sediment, retained large wood debris, enhanced stream complexity, increased leaf litter and insect inputs, increased stability of the alluvial channel and decreased stream velocity to provide slow water refugia. Early settlers converted the vast majority of the timbered Coquille bottom-lands to emergent grasses or upland prairies to make the valley habitable and allow agricultural development (Coquille River Subbasin Plan, 2007, p. 23). Past land practices cleared all vegetation, drained wetlands, dredged the river and created artificial dikes by depositing the soils in the floodplain.
Historically timbered swamps or marshes provided critical over-wintering habitat for juvenile coho. Lack of slow water refugia is a severely limiting factor for recovery of the ESA listed Coquille coho population. The lower Coquille River maintains floodplain connectivity, although, off-channel habitat essential in providing juvenile salmon refugia, crucial nutrients, and rearing habitat are greatly reduced.
The Pacific Coast Joint Venture (PCJV) identifies the Coquille River Valley as the most important waterfowl area between San Francisco Bay and the Columbia River. The area is critically important to numerous species of waterfowl and shorebirds during migration and wintering periods. According to the PCJV, the area is rated as high priority in the U.S. Fish and Wildlife Services ranking of waterfowl habitat protection and restoration needs, and is the agencys number 1 priority for protection and restoration in Oregon.