ASI Successfully Completes Inspection of One of the Tallest Dams in the US

ASI Marine L.P. (ASI) was contracted by Yuba County Water Agency to conduct an underwater inspection of the New Bullards Bar Dam located in Camptonville, California. The variable radius concrete arch dam spans over 2,300 feet and has a height of over 600 feet, making it one of the tallest dams in the United States. The purpose of this project was to assess the upstream face of the dam, identifying any anomalies in the concrete, including any cracks and spalling. In addition, the intake structures and outlet works were also inspected. This inspection provides the client with a baseline of data from which future inspections will be compared, identifying any potential areas of interest that can be specifically assessed over time.

 

Seaeye Falcon ROV

 

The inspection was successfully completed using a variety of sensors, including HD video cameras, 2D multi-beam imaging sonar, USBL positioning and a side-scan sonar mounted on to ASI’s Seaeye Falcon ROV. ASI completed this inspection using an ROV-mounted Side Scan – boat-mounting wasn’t an option due to the depth and geometry of the dam. During the collection of side-scan data, areas of interest were flagged and visually investigated with the ROV to provide context for the sonar findings.

 

Example of interactive side scan sonar survey

 

ASI’s final deliverables to the client included stitched sonar imagery of the entire upstream dam face in an interactive PDF format. The PDF provides a means of easily correlating video stills with the sonar imagery, all in reference to elevation and position along the dam face.