Dam Bulkhead – Gate Installation / Del Valle Dam
Owner: California Department of Water Resources
Ballard Marine Construction was contracted to install a 38,000 lb. octagon shaped bulkhead into the bulkhead slot of the intake tunnel located approximately 200’ offshore in the Del Valle Reservoir in Livermore, CA. Using a 300 ton crane, the Ballard team assembled three sections of 10’x 40′ floating barges as a work platform for personnel and equipment. The bulkhead / gate slot is located in excess of 90’ of water. To allow additional work time underwater, divers utilized surface decompression to conduct cleaning, inspection and repairs of the bulkhead slot sealing surface prior to the installation of the bulkhead. The bulkhead was lowered into the slot using deck mounted wenches, as the diver guided it into position. The tunnel was dewatered to enable California Department of Water Resources to walk the tunnel for inspection and re-coating purposes.