You Wouldn't Believe What They Put (And Didn't Put) In This Dam: The Deconstruction and Breach of Gunter Valley Dam

The decision to breach a large embankment dam is often made in response to the presence of a serious deficiency or group of deficiencies within the dam that are unable to be adequately rehabilitated for any number of reasons including lack of need, site constraints, governing regulations, and cost. Such was the case at the 83-foot-high Gunter Valley Dam in Pennsylvania. Breaching a large embankment dam also presents a unique opportunity for engineers, geologists, and dam safety professionals to observe the dam materials, subsurface structures, design details, and construction methods firsthand.
The breach of the embankment material at Gunter Valley gave the authors an opportunity to view and evaluate the inner workings and performance of the dam 58 years after it was put into service. The systematic removal of the embankment material exposed the dam embankment layer by layer, and uncovered deficiencies unlike any inspection or subsurface exploration program would have. Engineering design features were inspected for effectiveness. Unidentified site-specific geologic conditions and their impact on the performance of the embankment were also exposed. Results of the construction methods and installation quality of specific dam elements were viewed and evaluated. These firsthand observations were compiled and compared against the evaluations that lead to the decision to breach the dam. The observations and findings uncovered during the breach of Gunter Valley Dam provide dam safety professionals compelling evidence why modern dam design principles are so important.