The 2,000-foot tunnel is a key feature of the Chimney Hollow Reservoir Project. It will convey pipe from the valve house to the upstream side of the dam, allowing water to flow in and out of the reservoir. On the upstream side of the tunnel, pipe is being placed starting from the valve chamber at the tunnel’s midpoint, and then it is backfilled with concrete until it reaches the upstream entrance. This process is about 50 percent complete.  

On the downstream side, the tunnel entrance is 26 feet in diameter and all the concrete slabs that make up the flooring have been placed. Crews are now starting to line the tunnel with concrete using horseshoe-shaped liners. Personnel will be able to access the downstream side of the tunnel up until the valve chamber.  

Construction of the upstream side of the tunnel will be complete by October 2024. The entire tunnel is expected to be complete by the end of 2024.