Lamping Dam Geotechnical Investigation

Summary

Kaskaskia Engineering Group, LLC (KEG) provided geotechnical field exploration and engineering services to the USDA Forest Service Eastern District and Wayne National Forest in Monroe County, Ohio. The project consisted of a geotechnical investigation of an existing dam for a 5-acre pond located at the Lamping Homestead Recreation Area within the Wayne National Forest.

Project

The existing dam and pond are estimated to have been constructed between 1968 and 1972, based on review of historical topographic map data of the area. We understand the pond was constructed prior to the property becoming part of the Wayne National Forest and, therefore, no existing historical subsurface data was available prior to this exploration.  Based on a prior survey drawing of the pond completed by others and provided by the Forest Service; the pond was up to 21 feet in depth.

After an Award Letter was issued on May 9, 2019, KEG personnel arrived on-site to complete the work by July 25, 2019. The fieldwork portion of the project which consisted of two borings through the dam was completed in two days.  The KEG field engineer completed the field logging of each boring, obtained pictures, and took measurements of all rock core runs.  Laboratory testing was completed on the soils and rock encountered in the dam for the development of the analysis parameters.  KEG’s geotechnical staff performed slope stability analysis using the geometry of the upstream and downstream slopes of the dam in its current state and based on the soils, rock, and water “pool” elevation of the pond.  Factors of Safety for the stability of the dam were modeled for various conditions based on standard guidelines for dam stability and long-term design.  The boring and core logs were provided to the USDA Forest Service in a formal geotechnical report on August 12, 2019.  The Forest Service accepted the final report with no comments.