Canyon Dam Outlet Tower

November , 2009

Pacific Gas and Electric contracted us for this stem replacement project. We replaced approximately 80 lineal feet of stem,including stem guides and roller assemblies. The existing stem was attached to the vertical slide gate with rivets that were drilled out, enabling re-utilization of the holes to exacting tolerances.

Canyon Dam Outlet Tower in Lake Almanor,CA stands in approximately 85 feet of fresh water at 4,500 feet of elevation. To perform the project, we mobilized a portable barge system, a surface-supplied dive spread with decompression chambers, and a 20-ton hydraulic crane to the lake. The crane was driven onto the barge to assist with removal and replacement of large stem sections.

To remove the existing stem,divers utilized a hydraulic-driven magnetic drill press. The project was performed safely, efficiently, and within budget. Upon completion of the stem replacement, the stem was tested and performed within tolerances.