1 Introduction

New Graph Environment Ltd. was retained by the Ministry of Transportation and Infrastructure in the summer of 2022 to conduct effectivness monitoring at three sites in northern BC. Study areas for 2022 field work included Bittner Creek, within the Prince George city limits in the Tabor River watershed group, Cross Creek on the west shore of Babine Lake in the Babine Lake Watershed Group near Burns Lake BC, and Five Mile Creek located approximately 11km east of the town of Williams Lake within the San Jose River watershed group.

The health and viability of freshwater fish populations can depend on access to tributary and off channel areas which provide refuge during high flows, opportunities for foraging, overwintering habitat, spawning habitat and summer rearing habitat (Bramblett et al. 2002; Swales and Levings 1989; Diebel et al. 2015). Culverts can present barriers to fish migration due to low water depth, increased water velocity, turbulence, a vertical drop at the culvert outlet and/or maintenance issues (Slaney, Zaldokas, and Watershed Restoration Program (B.C.) 1997; Cote et al. 2005). Replacing barrier structures with road stream crossings that better facilitate fish passage can help to restore natural fish migration patterns, improve the quality of the aquatic ecosystems, and enhance the overall health of fish populations. As the costs and effort required for works to remediate fish passage issues through the replacement of road/stream crossings can be significant, effectiveness monitoring is a prudent measure to help understanding conditions for target fish species and inform adjustments and modifications based on the results of the monitoring. Additionally, monitoring can facilitate adaptive management, where managers use feedback/lessons learned from monitoring to modify future projects to achieve greater success.