Cabinet Gorge Dam, AVISTA Utilities – Fish Passage Project

AUS was contracted to provide the underwater support to construct a dewatering structure so that the fish passage facility could be built in the dry.

Divers performed the following tasks during the project:

  • Drill and install anchor bolts to secure the stanchions
  • Place grout under the stanchion base plates
  • Scribe and burn sheet pile to follow the contour of the bedrock
  • Install cross bracing
  • Underwater burning and welding
  • Seal the structure
  • Remove sheet pile