PROJECT: COUGAR DAM ROCKFALL HAZARD MITIGATION, McKenzie, Oregon


Rockfall Attenuator Catch Fence

Landslide Technology performed rock slope hazard evaluation and mitigation designs for the Corps of Engineers Intake Tower reconstruction project at Cougar Dam. A basic strategy for preventing rockfall into the work areas was developed at an initial site visit. Steep slopes and highly weathered loose rock prevented removal of all the potential hazards. Highly irregular slopes necessitated a complex design to control rolling and bouncing rock. After extensive rockfall modeling, a multifaceted plan was devised which limited the potential of rockfall hazards through scaling, rock bolts, draped mesh, rockfall catchment barriers, and very tall modified rockfall attenuatory fences. Follow-up visits were made to determine the effectiveness of scaling and the need for further remediation.