Monitoring flood impacts at the site of the Smithland scheme, Kentucky

During excavation work for the 72 MW Smithland hydro scheme in Kentucky, USA, record flooding occurred, with river levels projected to exceed the 100 year flood level and the cofferdam crest elevation. To mitigate the damage that would be caused, the site was intentionally flooded by breaching the cofferdam at the location of the planned emergency flooding structure, constructed as the excavation progressed. This article discusses how the project team monitored the performance of the embankment and excavation site as river levels rose, during the intentional flooding and subsequent dewatering of the excavation site.