Chilliwack River Clay Slides Gap Analysis


Year 2007
Proponent Chilliwack River Action Committee
Project type Habitat
FSWP funding source Living Rivers
Grant amount $19,050
Total project value $20,300

Location: Fraser Valley, Chilliwack, BC

Project Summary

The Chilliwack River Action Committee (CRAC) assessed the geomorphology of nine clay slide areas on the Chilliwack River to identify knowledge gaps of each slide, analyze the effects of clay slide siltation on downstream fish and fish habitat, and identify additional studies or works required to stabilize landslide and erosion sites in Chilliwack River. The project was initiated with a site meeting in February of 2007 to evaluate and characterize each landslide through observation, discussion, the formation history and existing conditions, stability and activity.

The second stage of the project involved a literature review focusing on the effects of clay slide siltation on downstream fish and fish habitat in the Chilliwack/Vedder River, and any stabilization works. In the final project stage, a final report was written, consisting of a synopsis of the literature review, gap analysis and work plan recommendations. This project found that sediment inputs from landslides have a negative effect on salmonid survival in the Chillwack/Vedder River, and recommended implementing a suspended sediment monitoring program in the Chilliwack River starting with continuous monitoring at Vedder Crossing. Further recommendations include stabilization works in the high priority areas of Anderson Run, Slesse Park, and Tolmie.