This restoration project was the first stage of restoration following the Coweeman Headwaters design (16-1668). The Lower Columbia Fish Enhancement Group restored natural processes to 1.37 miles of the Coweeman River watershed that was previously degraded by historic splash damming. The project focused on Tier 1 habitat with a focus on natural origin, ESA-listed, Lower Columbia Chinook, coho, and steelhead. For this phase of the implementation, we focused on the lower four reaches of Baird Creek (BR1-BR4; 0.99 miles), the furthest downstream reach of the Coweeman (CW1; 0.23 miles) and the furthest upstream reach of the Coweeman (CW9; 0.15 miles). In completing this project, we installed 47 instream structures, activated 2.68 acres of floodplain habitat, and revegetated 7.01 acres of riparian area. Through this project we refined known restoration techniques and tuned them for utilization throughout the Coweeman watershed. Weyerhaeuser was a great partner on the project, donating trees from their RMZs and boulders from local quarries.

 

The Coweeman River offers a unique opportunity to enhance fish productivity in the Lower Columbia River in a watershed where three primary species (Chinook, coho, and steelhead) have access to the headwaters without impairment from dams or waterfalls. The headwaters are also entirely managed by a single landowner, Weyerhaeuser. Despite the enhancement potential, no recent efforts had been undertaken to improve the quality and quantity of fish habitat in the headwaters portion of the Coweeman River and its tributaries since Weyerhaeuser and WDFW completed a near-term treatment in the late 1990s; most of which is no longer present today. Historic forestry practices, splash damming in both Baird Creek and the mainstem, and dynamiting of in-stream boulders, removed natural roughness elements and flushed much of the large wood and mobile bed material from the upper reaches. Re-accumulation of wood and gravel had been inhibited by the lack of new recruitment of large, mature conifers that act as key logs capable of creating and maintaining log jams in this high energy environment. As a result, reaches that previously contained mixed bedrock-alluvial channels now flow over bedrock, limiting the quantity of available spawning and rearing habitat. Although the upper watershed contains abundant supplies of cold water and suitable-sized sediment, the limited wood supply and corresponding roughness elements prevented the accumulation of bed material, limiting the productivity of salmon and steelhead. In addition, summer stream temperatures downstream of the project area are uniquely high in Coweeman River as compared to other Lower Columbia watersheds. The primary goal of this project was to re-introduce complexity and hydraulic roughness, thereby increasing planform variability which supports pool formation, development of spawning beds, and other critical habitat elements.Anecdotal results show a positive response from coho salmon and steelhead who are spawning in many locations in Baird Creek where there was previously no spawning habitat available.