The Gauley River in Summersville, West Virginia, is one of the best rivers in North America for whitewater rafting. The U.S. Army Corps of Engineers controls the river's flow rate by releasing water through three 11-foot diameter conduits from a 390-foot tall dam.

Gauley River Power Partners L.P. built an 80-megawatt hydroelectric power plant at the base of the dam to take advantage of this renewable energy resource. CB&I was retained to design and install a penstock and bifurcations to divert water from the river to the power plant. We provided engineering, procurement and construction services for the project, taking care to perform the work with minimal disruption to the dam's operation.

We designed and built the penstock to feed the water to the power plant. The diameter of the penstock ranges from 10.2-17 feet; material thickness ranges from 0.6-4 inches, and its length exceeds 350 feet. The penstock connects one of the existing 11-foot conduits to the spiral cases of two new 40-megawatt power generation turbines. The assembly also includes a conduit that allows water to bypass the power plant if necessary.

We designed and installed two bifurcations in the penstock in order to individually feed water to the powerhouse turbines as well as to the bypass conduit. One bifurcation has a 17-foot diameter inlet and 17-foot and 11-foot diameter outlets. The other bifurcation has a 17-foot diameter inlet and two 11-foot diameter outlets.

Since the project site was very remote and provided limited working space, we erected large assemblies in an open area two miles from the site. The assemblies were then transported by road to the installation site. Through careful planning and specialized rigging, we were able to safely lift the assemblies into their final position.

In order to maintain use of the river for whitewater rafting, the Corps of Engineers required that a portion of the penstock be installed in a very short time. The final 85-foot section was installed in only three weeks. Overall, we completed the project on time and in a manner that minimized the impact of construction on the dam's operation.