WorldWide Drilling Resource® 257 Caroline Street Punxsutawney, PA 15767 800-927-0560 • 814-427-2555 Fax: 814-427-5164 SERVINGTHECONSTRUCTION INDUSTRY Serving the Drilling Industry 36 JULY 2020 WorldWide Drilling Resource ® Blasting to Make Way for Salmon Migration Adapted from Information by the Government of Canada and Province of British Columbia Authorities were notified of a landslide in a remote, rugged canyon along the Fraser River north of Lillooet, in British Columbia, Canada. Huge pieces of rock from a 410-foot cliff sheared off and crashed into the river, narrowing it, and creating a 16-foot waterfall. The obstruction was so large, salmon migrating upstream had difficulty getting beyond. A Unified Command was formed of experts and spe- cialists from the Government of Canada, Province of British Columbia, and First Nations to respond to the emergency. To start, it was determined the immediately threatened salmon needed to be helped past the blockage. The movement was achieved by trapping and transporting the fish; rock scaling crews also manipulated some of the rubble; and the naturally lowering water levels encouraged migration. The next step was to actually clear the debris for future salmon migrations. The idea was to blast it away; so an access road was constructed to allow heavy equipment to reach that area of the river. The first blast resulted in a noticeable improvement to the water flow, but also exposed additional rock, which was subsequently drilled and blasted. Acoustic monitoring downstream of the slide did not detect any fish in the area before detonation, and no fish mortality was observed. Because the resulting flow could remain too strong for fish during high water, com- pletion of a “nature-like” fishway on the west side of the landslide marked a significant milestone for the project. The fishway mimics the natural river environment in which fish swim past obstacles or through fast-flowing water. It includes resting pools and passable rapids similar to what’s found in many river systems, to maintain the critical energy reserves fish need for migration. Using heavy machinery, material removed from the river was used by crews to strategically place clusters of boulders to disperse the current and slow the river along its edge. The top of the fishway also consists of a 13-foot bench with rocks placed to create the resting pools for fish during high water. The team will assess conditions and monitor passage throughout the next migration season to determine the fishway’s effectiveness. Editor’s Note: In between our print issues, the WWDR Team prepares an electronic newsletter called E-News Flash . This newsletter is filled with articles not included in our print issue. Based on readership, this was the most popular article of the month. Get in on the action and subscribe today at : EXB Image courtesy of the Province of British Columbia.