PITTSBURGH -- WHO: U.S. Army Corps of Engineers Pittsburgh District (USACE).
WHAT: The U.S. Army Corps of Engineers is hosting a public meeting to discuss the progress and activities of the East Branch Dam Safety Modification Project in Elk County, Pennsylvania. The primary purpose is to provide the public with a construction update about the Dam Safety Project and to allow the community to ask questions and provide feedback. Other agencies are scheduled to attend and will provide valuable information about the common interests we share in this project.
WHEN: Monday, March 2, 2020, at 7 p.m.
WHERE: Johnsonburg High School Auditorium, 315 High School Road, Johnsonburg, PA 15845.
WHY: The district is committed to communicating the efforts and progress related to the East Branch Dam Safety Modification Project to all interested and affected parties and to provide opportunities for the public to express concerns and provide input.
Project Status: The Army Corps of Engineers’ contractor completed the installation of the seepage cutoff wall in the August 2019. During normal quality-control procedures, the Corps discovered two areas of the cutoff wall that did not meet contract requirements. There are no associated safety concerns, however, the contractor is required to remediate these areas and is in the process of doing so now. The 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 dam into bedrock. The seepage cutoff wall construction contract is expected to be substantially completed by the end of the 2021 calendar year. Following verification of the completed repair and subject to local weather conditions, the USACE will begin to return the reservoir to its former operating conditions and water levels.
Background: Public safety is the number one priority of the district’s Dam Safety Program. In 2008, the Pittsburgh District initiated a dam safety investigation into seepage-related concerns at East Branch Clarion River Lake in Elk County in western Pennsylvania. To reduce the risk to the public, the Pittsburgh District implemented several interim risk reduction measures including increased monitoring, continuous on-site staffing, updated emergency action plans, and lowered water levels in the reservoir to relieve pressure on the dam. These, and other short-term actions, have allowed the district to minimize dam safety risk while still fulfilling the authorized purpose of the dam until permanent risk reduction measures are completed.
A Dam Safety Modification Study was completed and approved in October 2010. In August 2014, the Pittsburgh District awarded the $132.5-million East Branch Dam Cutoff Wall Rehabilitation Project to Layne Christensen Company of Ruther Glen, Virginia. The company’s Bencor Division, of Frisco, Texas is performing the dam safety work and was subsequently acquired by The Keller Group, LLC. The work consists of constructing a full-depth seepage cutoff wall within the existing earthen embankment dam.
The original project cost, $280 million, included the cutoff wall effort as described above. It also included ancillary work, which includes access-roadway improvements, additional instrumentation, lighting, and other project requirements. We expect the project will not exceed the original cost estimate, but it will likely exceed the 2014 baseline cost estimate of $248 million.
Following the completion of the cutoff wall construction, USACE will evaluate the repair to ensure that it meets the agency’s dam safety standards. Upon verification, the district will implement a water management plan that incrementally raises lake levels while monitoring the performance of the repair.
The district’s primary objective is to ensure public safety while returning the operation of the dam and management of the reservoir to its normal operating condition.
For more information, visit: www.lrp.usace.army.mil and join us on the East Branch Dam Facebook Page.
Follow the Pittsburgh District: Twitter, Facebook and Flickr.