Final Season of Winter Construction Underway

Feb. 10, 2025

Final Season of Winter Construction Underway

Despite the snow and drops in temperature, crews persist through winter weather conditions to remain on schedule to complete Chimney Hollow Reservoir this summer. Here is a look at projects that have been completed this winter, others nearing completion and those that will remain this spring.

Finished Projects

The 40-foot-tall saddle dam was completed in November. Construction of this dam began in May 2024.
The Bald Mountain interconnect and Carter Lake interconnect elements were completed in December 2024.
Concrete placements of the spillway concluded in November 2024.

Projects Near Completion

Crews are in the process of replanting and rebuilding the soil of disturbed land previously excavated near the Chimney Hollow conduit.
The installation of only three valves and 800 feet of pipeline remains in the inlet/outlet tunnel. All other conduit and valves are installed.
Electrical and fiber-optic cable installation is currently taking place inside the valve house. Crews have already installed most of the pipes, valves, windows, plumbing, heating, ventilation and air conditioning. The construction of the structure is on track to wrap up late spring when it will be ready for testing.
Zone 4 rockfill material is the largest amount of material to be placed on the main dam. In late November approximately 98 percent of the rockfill had been placed. In addition, because the dam has become narrower and is more congested with trucks, placement of zone 4 rockfill moved to the night shift, because as the dam becomes narrower, it is more congested and difficult for all of the trucks to move around. To prepare for this night work, zones 1 (asphalt) and 2 are still placed during the day. By volume, crews have placed approximately 94 percent of all the rock material (zones 2-6) on the main dam.

Remaining Projects

The inlet/outlet tower, located outside the tunnel on the right abutment of the main dam, is projected to be complete by late spring.
The pipe that will bring water in and out of the reservoir will be installed in the downstream tunnel this spring.
Crews will work to backfill the spillway, the majority of which is buried underground.
The removal of the cofferdam will occur this spring.
After all major construction projects wrap up, all that will remain is revegetation, site cleanup and move out.

Although there are a handful of elements left to complete, the bulk of the main work on the project is nearly complete. As a result, the number of workers on site has been reduced by about half the peak amount, from 500 to roughly 250 each day.

Weather permitting, remaining crews aim to wrap up construction this summer when project managers plan to begin bringing water into the new reservoir, which is expected to take about three years.