Scanning Sonar Applications for Dam Inspections and Bathymetric Surveys

Reclamation's Technical Service Center has been using a scanning sonar system since 2011 to image underwater structures in both clear and low visibility water to produce 2D acoustic images and high-resolution 3D point cloud data sets. Scanning sonar systems are analogous to laser scanning systems used for terrestrial LIDAR surveys. This sonar technology is well suited for hydraulic structure inspections, underwater search and recovery, and creating as-built images/3D models of underwater construction projects. Applications include bathymetry surveys, contour mapping, hydraulic structure inspections for structural damage, fish screen inspections, scour hole monitoring (shape and volume), and sediment/debris accumulation around penstock intakes. Several examples of recent applications will be presented to demonstrate the utility of scanning sonar technology for hydraulic structure inspections.