Meacham Creek RM 10-11 Floodplain and In-Stream Habitat Restoration

The CTUIR’s Meacham Creek RM 10-11 project will be the 5th year of floodplain restoration in the Meacham Creek Watershed. The Project lies just downstream of the confluence of Camp Creek in T01N, R33E, in portions of sections 5 and 8, Umatilla County, Oregon. The Project area is located on USFS land, but directly abuts privately held parcels. The Union Pacific Railroad (UPRR) railway runs down the east edge of the valley and parallel to the river corridor. Over the past 150 years, the Meacham Creek floodplain has been disconnected from its floodplain due to the development and construction of the UPRR line that runs parallel to the stream. The development of the rail line led to extensive diking for protection, logging for fuel, and vegetation alteration that has left Meacham Creek straightened and confined against the valley wall, disconnected from its floodplain, resulting in a decrease in channel complexity, a lack of woody materials, and an overall simplification of floodplain processes. Meacham Creek lacks floodplain connectivity and habitat complexity for Endangered Species Act-listed Middle Columbia summer steelhead and Columbia River bull trout, as well as Chinook salmon, Pacific lamprey, and other first foods that utilize the watershed. The CTUIR will use these OWEB-allocated funds to perform instream channel structure placement. To view the entire project effort, view this project alongside CRITFC 23-Umat-02 in the PCSRF database.

The proposed restoration project on RM 10-11 will benefit steelhead, salmon, and other First Foods in several ways. First, floodplain connectivity will be increased by the removal of existing levees, berms, and spur dikes. Dispersing the material of the levees, berms, and dikes will allow Meacham Creek to access its floodplain and engage in greater hyporheic exchange from these seasonally wetted habitats. There will be increased shallow groundwater capacity to contribute to greater base flows and increased cool water inputs to reduce high summer water temperatures and provide cool water refugia. In-stream habitat complexity will be increased through the addition of large wood structures, the construction of side channels, pools, and alcoves, and increasing sinuosity. These seasonally disconnected habitats will provide cover for juvenile fish and to rear with less of a risk of being predated on. High summer temperatures are identified as a limiting factor for salmonid production in (see watershed assessment). Lastly, restoring riparian vegetation will increase shade which will create pockets of varying temperatures that are proven to increase productivity, rather than the previous school of thought. This will overall increase streambank stability to the channel as well as reinforcement of large wood that will be naturally recruited to the stream channel overtime. Complex wood structures provide shade and filter varying sediment sizes, further improving water quality. The large wood structures will additionally create scour pools for more varying temperature pockets, habitat, and diversity of cover (90% Design).