Instream Habitat Restoration in mid-Nicola River
Lack of stable complex habitats is a significant limiting factor in the recovery of Interior Fraser coho (Endangered, COSEWIC), early timed spring chinook, and steelhead. The section of the Nicola River rehabilitated during this project had been subject to a detailed survey for the purpose of prescribing appropriate instream habitat rehabilitation features (Gaboury and Matthews, 2007). The riparian area is characterized by relatively flat valley bottom silts/clay soils that are actively eroding in areas where large vegetation had been removed. Ongoing erosion of the streambank has resulted in significant channel migration. The erosion is a chronic source of sediment to the river which has long term and extensive impacts on fish rearing, holding, and spawning habitats downstream. Project goals included: 1. Provide over 3,000 m2 of stabilized complex instream holding, spawning and rearing habitat for Interior Fraser coho and early timed spring chinook. 2. Work with the landowner to develop a cooperative understanding around riparian corridor management, implementation of the work, contribution to the work by the landowner, and future management of the riparian area in the vicinity of the work. A total of 13 log and boulder structures were constructed at roughly 15m intervals along the eroding outside meander bend for a distance of 190m. Along with these structures riprap was placed along the bank, riparian areas were replanted, and livestock exclusion fencing was installed. Results include: 1. stabilizing banks reducing erosion potential and sediment input, 2. improving holding and rearing habitat for salmonids by increasing pool frequency and the amount of functional LWD cover in those pools, 3. re-establishing a more stable channel with appropriate bankful widths through an adjustment in the meander curvature, and 4. improving land management practices by riparian area owners