REMOVAL OF LARGE DAMS AND SITE RESTORATION - BREACHING OFBIRCH RUN DAM

摘要

Prior to its removal from service in 2005, the 72-year old, 65-foot high, 700-foot long earth fill Birch Run Dam was the number one dam on the Pennsylvania Department of Environmental Protection's (PADEP) Division of Dam Safety's (Division of Dam Safety) list of unsafe dams. Located in Micheaux State Forest in south central Pennsylvania, the water supply dam represented a high hazard potential to the downstream population of over 11,000. Persons at risk included residents of Chambersburg, PA, seven nearby townships and three schools with a combined school population of 2,200. The Division of Dam Safety requested the dam owner, the Borough of Chambersburg (Borough), to address inadequate spillway capacity and other dam safety deficiencies or remove the dam from service. Alternatives studies were performed for repair, replacement and removal, which considered costs and impacts on the stream environment, wetlands, forest, and system safe yield. This paper presents the removal of Birch Run Dam as a case study and includes lessons learned from this project.