Mainstem river fish habitat restoration projects have been conducted in a number of impacted
watersheds across the Lower Mainland/South Coast of British Columbia by the BC Conservation
Foundation Fisheries Recovery Program. The primary habitat restoration methods used to improve
juvenile fish rearing habitat was the Large Woody Debris (LWD) engineered style log jam, and sidechannel
re-connections. This FSWP project was funded to assess the biological performance, and
structural integrity of the restoration projects. Rather than attempting to evaluate all restoration
projects, a sub-set of projects was deemed practical. In the Fraser Valley, the Alouette and Chehalis
River, and the Silverhope Creek have been selected (Appendix I – Map).
Using fish habitat restoration effectiveness monitoring industry guidelines, LWD structures, and select
control sites were evaluated to determine fish abundance using underwater snorkel survey
methodology. The key focus was enumerating juvenile steelhead trout (Oncorhynchus mykiss), and
coho salmon (Oncorhynchus kisutch) at treated (restored), control (un-restored), and where available,
natural wood controls (natural wood). This involved summer day-time, and winter night-time snorkel
survey assessments, conducted to capture data representing seasonal habitat use variability. Snorkel
surveys were conducted between August 18 and August 26, 2009 for summer evaluations, and
February 2 and March 15, 2010 for winter evaluations. Overall, underwater snorkel survey
observations indicate a high salmonid fish use at wood restored sites, as well as natural wood sites,
relative to the controls with no wood present (refer to section 3.2 “Effectiveness” for study results).
Additionally, a side-channel mark and re-capture juvenile salmonid population estimate was conducted
on one of two re-connected side-channels in the Silverhope Creek.
Large Woody Debris structural performance (habitat development) was rated using a standardized
methodology. Of all 75 LWD restored sites that were evaluated, 94% and 92% are at or above the
“meets expectations” criteria ranking for “pool development and gravel deposition” and “fish habitat