The US Army Corps of Engineers, Pittsburgh District announced that Layne Christensen Company of Ruther Glen, Virginia, has been awarded the $132.5-million contract for the East Branch Dam Cutoff Wall Rehabilitation Project. The work consists of construction of a seepage cutoff wall within the existing earthen embankment dam, located in Elk County, Pennsylvania.
The seepage cutoff wall consists of a minimum 18-inch-wide continuous vertical concrete cutoff wall approximately 2,300 feet long with an approximate maximum depth of 250 feet through the existing embankment into bedrock. It is estimated that the contract will take approximately four years and nine months to complete.
East Branch Dam is located on the East Branch Clarion River, 7.3 miles upstream of its confluence with the West Branch Clarion River at Johnsonburg, Pennsylvania, where they form the Clarion River. The Clarion River is a major tributary of the Allegheny River. East Branch Dam is part of the comprehensive flood damage reduction plan for the Ohio River Basin. The project purposes are flood control on the Clarion River, water quality, low-flow augmentation, recreation, and conservation of fish and wildlife.
Public safety is the Army Corps Dam Safety Program’s number one priority. East Branch Dam has a history of seepage-related problems, including a serious seepage episode in 1957 that required lowering the lake until repairs could be made. In 2008, the Pittsburgh District initiated a dam safety investigation of seepage-related concerns at East Branch. To reduce the risk to the public, Pittsburgh District implemented several interim risk reduction measures, including increased monitoring; 24/7 staffing; updated emergency action plans; and reduced water levels in the reservoir to relieve pressure on the dam. These and other short-term actions allow the Pittsburgh District to operate the dam and to meet Army Corps public safety objectives until the seepage cutoff wall is complete.
For more information, visit: www.lrp.usace.army.mil
Release no. 14-240