Mill/Beaty Creeks (Alsea) Restoration

The Mill-Beaty Creek subbasin includes over 5.2 miles of stream network and drains into the Alsea River one mile downstream from the town of Alsea (Benton County). Proposed restoration actions take place throughout the subbasin, the majority of which upstream from the Mill/Beaty confluence is in Bureau of Land Management (BLM) ownership and managed for late seral reserve conditions. A long history of poor timber practices, agricultural activities, and a private lumber mill in the basin have severely degraded fish and wildlife habitat, and resulted in a channelized, incised stream network with little floodplain connectivity or stream complexity in a majority of the basin. This Phase II effort builds on previous work in the basin over the last two years, and will include replacement of two fish passage barriers, channel reconfiguration and channelization, spawning gravel placement, placement of logs or whole trees instream, and riparian plant establishment along the stream network. Project partners include all major landowners in the subbasin: the BLM, Weyerhaeuser, US Forest Service, and three private landowners. Project assistance is provided by the Oregon Department of Fish and Wildlife and the Lincoln Soil and Water Conservation District.
FFY2022 IIJA funds will be expended on project costs incurred during the FFY2022 PCSRF contract award period. Other fund sources will be used to complete the project. No funds are reported as match to PCSRF.

Fall chinook and OC coho adults currently spawn in Mill and Beaty Creeks within the project site and upstream (while steelhead migrate through and spawn higher in the sub-basin). This project intends to trap transient gravel resources with wood placements, which will boost the quantity of well-sorted spawning gravel and enhance spawning success for both of these species. In addition, the morphological changes in the streambed associated with aggradation (accumulated bedload) will provide summer water storage in a hyporheic lens that is protected from solar exposure.

This input of cool water will benefit the rearing for all species of salmonids by reducing summer temperatures. The project also will create increased floodplain connectivity along the mainstem Mill Creek to provide exceptional off-channel habitat capacity for winter rearing. The restored connection to floodplain areas provides additional salmonid rearing areas, and will alter the average stream gradient to reduce scour and bedload migration and recharge floodplain terraces. This will also moderate summer temperatures for rearing salmonids.

Removal of undersized, perched culverts and replacement with appropriately sized structures will ensure salmonid and aquatic organism passage to upper watershed areas. Riparian planting will increase shade, food resources for juvenile fish from terrestrial insects, provide cover, and establish conifer in the riparian area for long term recruitment of LWD to the system.