Advanced American Construction (AAC) was awarded a firm fixed price contract by the Bureau of Reclamation to mobilize crew and equipment into Trinity Lake and remove the existing spherical bulkhead for refurbishment and upgrades. This required AAC to mobilize floating equipment into the remote lake to safely remove the bulked from its home for over 60 years.

Refurbishment was completed onsite in a temporary work shelter constructed by AAC and team.  Refurbishment included new machined components, testing and inspection of the bulkhead, new seals, fabrication of a new backup seal mount and painting.

The in-water bulkhead guides were inspected, and the sealing surface was also cleaned by AAC’s dive team.  Once refurbishment was complete, the bulkhead was seated at the intake entrance and the conduit from the lake to the powerhouse was drained.  A full tunnel inspection was performed in the dewatered conduit.  Following inspection, the bulkhead was raised to its storage position.