Tennessee Valley Authority
Bear Creek Dam Rehabilitation
May 2009
Since its completion in 1969, the earthen Bear Creek Dam has experienced foundation leaks. Previous efforts to control leaks have been ineffective over the long term.
Following periods of heavy rainfall, the reservoir level can rise, and increase the risk of dam failure. To reduce this risk, TVA prepared an Environmental Impact statement to evaluate alternatives for a long-term solution. After thorough study, public involvement, and several opportunities to provide comment, TVA signed a Record of Decision on September 10, 2007 stating it would build a roller compacted concrete structure at the downstream toe of the existing dam along with a water cutoff "wall" under the new structure to block water passage under the dam. Site preparation began in September 2007.
Construction Report Update
Safety and Environmental Issues
Continued emphasis is being placed on safety and environmental performance at Bear Creek. To date, contractors have experienced six near misses, six first aids and three reportable events.
Dewatering System
The dewatering system is no longer required and has been removed. All but one well has been filled with concrete.
Roller Compacted Concrete Production
The placement of the roller compacted concrete (RCC) was complete May 1, 2009, with a total of 88 lifts. An additional one-foot, conventional concrete slab has been poured on the dam crest to protect the RCC structure.
Gallery Work:
Work continues on pouring concrete steps and floor in the gallery. Lighting and instrumentation is currently being installed in the gallery.
Backfill Operations
The backfill operations continue on the upstream and downstream side of the RCC dam.
Current Activities:
- All RCC work, 88 lifts, and conventional concrete crest work has been completed.
- Work continues on placing concrete steps and floor and instrumentation in the gallery.
- Backfilling operations on the upstream and downstream side of the dam continue.
- All remaining construction activities are scheduled to be complete in June, 2009.
View of conventional concrete placement on the crest of the RCC dam.
View of backfill operations along upstream face of RCC dam.
