Tennessee Tech Team Develops Low-Cost Early Warning Flood Sensors

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The Tennessee Conservative [By Jason Vaughn] –

Dangerous floods that seem to follow extreme rainfall events are happening more often in Tennessee.

Climate scientists, engineers and emergency managers are attempting to respond to this by relying on environmental data. The problem is, though, that is scarce in Tennessee.

Other than on major rivers near urban centers the state lacks flood sensors.

“Rural areas are where we don’t have any eyes on the ground,” said Alfred Kalyanapu, an engineering professor at Tennessee Technological University.

This is also a problem for other environmental conditions in Tennessee like soil moisture and barometric pressure. At least 35 states have mesonets, a system of sensors that track environmental conditions. According to scientists, these improve extreme weather forecasts.

In 2017, Kalyanapu began looking into flood-specific sensors to complement mesonet data. He worked with students to create a low-cost solution to what he considered a significant infrastructure scarcity. He gathered the initial support for the project through a U.S. Geological Survey grant. 

Kalyanapu’s team built devices that sit vertically above a body of water that will send sound waves down at a 42-kilohertz frequency and record how long it takes for the echo of the sound to return. This provides an accurate measurement between the sensor and the water. 

If the data points start rising between measurement intervals, there is probably a flood. Most of the time, though, these graphs will appear to be rather boring. 

The data shown from these can help us better respond and prepare for inevitable disasters, Kalyanapu said. It can decrease the time between official warnings and danger. 

Kalyanapu said, “You cannot just blindly say, `Hey, I have a sixth sense that tells me that’s going to flood,’ You need data to inform your decisions.”

When placed beside an official USGS gauge and compared, it was shown to be as accurate as the official ones. The only difference is that Kalyanapu’s sensors cost $500 whereas the commercial equivalent cost about $20,000. 

The town of Waverley, which experienced Tennessee’s second-deadliest flood event to date, recently had two of these sensors installed. Any community interested in installing a sensor can reach out to the university to request one. 

About the Author: Jason Vaughn, Media Coordinator for The Tennessee Conservative  ~ Jason previously worked for a legacy publishing company based in Crossville, TN in a variety of roles through his career.  Most recently, he served as Deputy Director for their flagship publication. Prior, he was a freelance journalist writing articles that appeared in the Herald Citizen, the Crossville Chronicle and The Oracle among others.  He graduated from Tennessee Technological University with a Bachelor’s in English-Journalism, with minors in Broadcast Journalism and History.  Contact Jason at news@TennesseeConservativeNews.com