Technological advances are making Tennessee Valley Authority dam inspections cheaper and much quicker.
New sonar equipment is being used in place of divers with video equipment and has cut inspection time for each dam down from about a week to a matter of hours. The technology, called Side Scan Sonar, is a combination of instruments attached to the side of a 22-foot boat that feeds data to a monitor.
“It’s an amazing tool to be able to look underneath the water and not have the limitations that you traditionally have with a video system,” civil engineer and dam safety inspector Benjamin Phillips said. “We’re now able to get a better view of what’s going on in our facilities.”
Previously, divers inspected dams several feet at a time. Now, civil engineers sit in the boat monitoring a screen feeding the data. That information then is displayed as a colorful, three-dimensional on-screen rendering at the end of the inspection. It is then further analyzed and compared over time with other inspections. The team also prints out the readings for future use.
Teams, usually consisting of two TVA civil engineers, work in tandem to use the sonar system to perform routine inspections on 49 area dams. Since TVA purchased the technology last year, they’ve inspected roughly half of those.