Dead Cow Gulch Fish Passage and Habitat Improvement

The project is complete. The majority of the construction for the Dead Cow Gulch channel realignment project was completed during October 2007. The work conducted was the creation of the new channel within the historic channel location, installation of five rock cross vane structures, installation of twelve rootwads/pool structures, installation of vehicle ford, and culvert removal. The work was conducted during the driest part of the year to avoid soil compaction from equipment and to reduce impacts to vegetation.

The channel excavation added ¼ mile in length to the tributary by allowing it to confluence with river at the historic location. The channel was designed to allow for floodplain interaction, provide holding pools, add LWD structure cover and fish passage. The cross vane structures were installed to provide for erosion control and to limit head cutting.

The stream will be diverted to the new channel location in July of 2008. This portion of construction will only require the removal of a dirt plug located near the confluence with the Middle Fork John Day River and the installation of a dirt plug at the diversion point. The delay will allow for vegetation to recover and provide channel stabilization once the stream is diverted. The channel reconnection project is within spawning and rearing habitat used by Mid-Columbia spring Chinook salmon, summer steelhead and in close proximity to known bull trout populations. The project is expected to benefits Salmonids by expanding available habitat through channel reconfiguration and restoring fish passage. Dead Cow Gulch is a high quality cool stream that will provide thermal refuse and add an addition mile of good rearing habitat.

Also, summer steelhead and possibly bulltrout would likely use portions of the stream for spawning. The access gained by salmonids to Dead Cow Gulch may decrease mortality rates of holding adult spring Chinook salmon and increase survival rates of juvenile salmonids.

The channel reconnection project will benefit all age classes of Mid Columbia spring Chinook salmon, summer steelhead, and bulltrout. The high water quality of the stream will provide much needed thermal refuge for juveniles and holding spring Chinook salmon during the summer months when river temperatures reach as high as 78° F. There is generally 35 to 70 adult spring Chinook that hold within a mile of the Dead Cow MFJDR confluence and 225 to 360 that spawn within two miles of the confluence. There are also areas of the stream suitable for summer steelhead spawning providing an expansion of available habitat.

Potential benefits of the project may decrease mortality rates of holding adult spring Chinook and increase survival rates from juvenile to smolt of both spring Chinook and summer steelhead. The upper reaches of Dead Cow may also provide suitable habitat for bulltrout and expand the severely limited population in the Middle Fork system.