Advanced deterioration and escalating rehabilitation costs will force breaching of the dam that once formed Gunter Valley Reservoir in Franklin County, the Department of Conservation and Natural Resources announced Tuesday.
Built in the early 1960s, the dam across Trout Run in Tuscarora State Forest was beset with concrete cracking and seepage. The 26-acre lake once formed by the high-hazard dam was drained by DCNR in October 2009.
"After long examination and discussion of structural concerns by our engineers and foresters, dam rehabilitation has been ruled out and breaching is the logical alternative," said DCNR Acting Secretary Ellen Ferretti. "DCNR estimates it would cost $20 million to $25 million to fully rehabilitate Gunter Valley Dam to today's dam safety standards."
Ferretti said projected rehabilitation costs increased substantially as DCNR learned more about the dam's embankment, foundation and control tower problems, as well as an inadequate spillway.
Amid increasing leakage from the dam, the lake was drawn down to enable DCNR officials to address structural concerns raised as a result of a joint inspection with the Department of Environmental Protection, which oversees dam safety.
The reservoir and surrounding 3,000 acres were purchased by DCNR from the Shippensburg Borough Authority and added to the Tuscarora State Forest in 2003. The borough stopped drawing water from the reservoir in 2007, and it no longer is necessary to meet the borough's needs.
"That watershed acreage has proved a valuable and popular addition to Tuscarora State Forest, and first-time visitors will find the tract enhanced with a number of new trails and parking areas," Ferretti said.
A dam breach and required stream-channel restoration in the impoundment area will be subjected to further site studies before bids are sought.
For more information, visit the Tuscarora State Forest webpage.