Low Head Dam Removals

Attended an excellent workshop on the removal of low head dams.  Their impacts can be far-reaching and include public recreational use, stream ecology, water resources, the transport of sediment and bound contaminants and others. It is key to understand the complexities of each dam and its unique local environment.

GPR imaging of ground water seepage within an earthen dam

 

This is one slice of a 3-D radar survey performed at an earthen dam in northeastern Indiana (click the image to enlarge). The bright areas near the center of the image indicate ground water saturation. A geotextile layer is imaged as an inclined planar surface, and breaching of ground water from the geotextile into the fill lifts is observed. This indicates failure of the textile to route seepage to the toe drain.