The Tennessee Valley Authority says new technology is helping engineers inspect dams more thoroughly and efficiently.
Using side-scan sonar mounted on a boat, civil engineers like Benjamin Phillips can get a real-time view of the dam beneath the water line.
“So the bright line here is the concrete face of the dam,” he said, pointing at a laptop screen.
TVA has been using the new rig for about a year. Phillips said previously, the dam safety inspection team used a combination of divers and robotic submarines to inspect the hundreds of feet of submerged concrete on the up stream side.
Tuesday, his team was working at Melton Hill Dam west of Knoxville.
“[Sonar is] dramatically increasing the efficiency, and we’re able to look at the entire facility, whereas before with divers, you’re really only able to look at what you can reach,” Phillips said.
He also noted that a dam can stay in operation during a sonar inspection, but generation had to be stopped if divers or robots were in the water. It’s also faster – what takes divers days to cover can be scanned in about an hour.
The software also compiles a 3D rendering of the entire submerged structure.
“We can really get a good grasp on what all the different features and what condition they’re in underneath the dam,” said Scott Kramer, manager of TVA’s Dam Safety Inspection Unit.
“So it really saves us time and we get a much better view under the water,” he added.
The new inspections, he said, means any issues are caught early. If the scan shows an issue in need of further inspection, the team can still send divers in for a closer look.
This ensures the dam is ready for anything thrown its way – from flooding, to earthquakes, to everyday debris floating down the river.
“With this technology, we can go in and make sure that all those safeguards are in place so we can keep the lights on,” said Phillips. “We’re seeing things better, and we’re doing it safer.”
TVA said the equipment will be used to inspect each dam in the system about once every five years, or in between if an issue arises.