CPC

Habitat Structure Update

Slocan River Rainbow Trout Habitat Enhancement Project Habitat Structure Update

Phase 1

The in-stream habitat structure component of the Project is now complete. The overall project occurred in two phases. Phase 1, the demonstration phase, saw the placement of five in-stream structures into the river during February and March 2005.

Monitoring results of rainbow trout utilization surveys conducted annually in late summer since habitat structure installation in 2005 have demonstrated increased use by the target size (over 20 cm) classes of fish over a two year period. Fish counts completed by underwater observation have shown that rainbow trout in excess of 20 cm fork length have colonized additional trout habitat provided by the structures. The highest counts have been associated with structures located in deep water areas of the channel. Observations conducted in late fall have shown that trout utilization declines as adult fish move to defined over-wintering environments elsewhere in the Slocan River or Brilliant headpond.

In addition to the fish use survey, a recreational use survey was conducted at various locations between Passmore and Winlaw from June until the end of August in 2005 and 2007. As well, river users were interviewed as they floated past the structures and at various take-out points along the river.

Survey findings indicated that the section of river where the habitat structures are located (Winlaw) is used considerably less than the sections downstream of the Passmore Bridge. The river users' knowledge of the project was high, with very few respondents not knowing what the structures were for. Further feedback will be obtained from organized river user groups in 2009.

Phase 2

As a result of the positive feedback generated from Phase 1, CPC began moving forward with plans for Phase 2 structure installation. An Open House was held on Saturday, February 23, 2008 at the Passmore Hall to introduce the Phase 2 plans to Valley residents.

Lessons learned from Phase 1, plus an engineering assessment of the original structures, resulted in six new designs for the additional 10 structures, as well as upgrades to the remaining Phase 1 structures. All structures were built using predominantly natural materials (e.g. douglas fir logs and root wads, local boulders, etc.) and blend well with the natural surroundings.

Throughout the entire process, care was taken to strike a balance between the needs of the fish and the goals of the river users. The new structures were only located along the channel margins of the river where conditions will promote long-term structure durability, maximize fish utilization and minimize risk to river users. A registered Professional Biologist oversaw all aspects of the construction process and a Professional Engineer ensured structural integrity.

All regulatory approvals were received and in September 2008, CPC proceeded with the installation of the additional structures.

Continued monitoring of fish use and changes to the biophysical characteristics of the structures will increase our knowledge of this restoration tool, and through adaptive management practices, the restoration program will improve over time.