For this client, a sonar survey was done through ice. After undertaking remedial work that involved a trial filling of a sinkhole, a sonar sounding survey of the headpond was conducted.

The purpose of the sonar survey was to assess the trial filling of the sinkhole, to inspect the condition of the upstream slope of the dam (in particular, the toe of slope and reservoir area within 50 ft of the toe), to study more efficient and detailed methods of reservoir bathymetry, and to investigate more accurate methods of measuring the volume and size of headpond depressions.

A key finding of the work was the presence of additional sinkholes and depressions located on the reservoir bottom upstream of the dam.