Upper Elk River and Flathead River Fish Passage Restoration Planning
New Graph Environment and Nupqu Limited Partnership were retained by the Canadian Wildlife Federation in the fall of 2020 to plan and conduct fish passage and habitat confirmation assessments at road-stream crossings as part of connectivity restoration planning targeting westslope cutthrout trout. Although some planning was conducted for both the Elk River watershed upstream of the Elko Dam near Elko, BC and the Flathead River, on the ground surveys in 2020 focused on the Elk River and tributaries located upstream of the Elko Dam.
A total of 72 Phase 1 assessments were conducted with 17 crossings considered “passable,” 8 crossings considered “potential” barriers and 43 crossings considered “barriers” according to threshold values based on culvert embedment, outlet drop, slope, diameter (relative to channel size) and length. Cost benefit analysis were conducted for each crossing determined to be a barrier based on estimates of the costs associated with fish passage remediation and the amount of habitat (linear and area) that would potentially be made available by remedial works.
Habitat confirmation assessments were conducted at 15 sites with a total of approximately 15 km of stream assessed. Six crossings were rated as high priorities for proceeding to design for replacement, 8 crossings were rated as moderate priorities for proceeding to design for replacement, 0 crossings were rated as a low priority and 1 crossing was rated as “no fix.” Cost benefit analysis were again conducted for each crossing assessed.