Remediation For Beach City Dam Seepage Deficiency

Beach City Dam was designed by the U.S. Army Corps of Engineers with construction completed in 1937. It is one of a system of dams designed to provide flood damage reduction in the Muskingum River Basin of Ohio, and is located on Sugar Creek of the Tuscarawas River, a tributary of the Muskingum River. The dam consists of a 6,000 ft-long predominantly earth embankment with a maximum height of 68 ft, and is built on a foundation consisting of pervious glacial outwash. Due to a history of excessive under seepage during events with frequent return periods, projected instability at design pools, and the project being ranked as urgent within the USACE inventory, a Dam Safety Modification (DSM) study was undertaken. The study included geotechnical explorations and reliability analyses, and the development of recommended modification alternatives for reducing project risk associated with all potential failure modes to tolerable levels. This paper provides an overview of Beach City Dam under seepage-related aspects, DSM study geotechnical analyses, and proposed remediation for this potential failure mode. Recommended rehabilitation measures for addressing main embankment seepage concerns include the infilling of a downstream lagoon, the construction of a seepage berm, the installation of additional relief wells, and the installation of a new collector system. A minimal seepage berm is also recommended for construction downstream of the railroad closure section. Associated with this plan are the construction of additional access roads, the removal of vegetation near the dam, the installation of additional instrumentation, and the development and implementation of a maintenance plan for ensuring adequate future relief well system performance. 20 pp, 11 figures, 10 references.