Signs of a Flood

On one December morning Larry McKay suited up in a rain coat and rubber boots and headed out into the Tennessee River basin.

A couple dozen other people joined him. They climbed down canyons, into caves, and through forests looking for scars on trees and specific kinds of deposits. What were they searching for?

Signs of a flood.

The expertise of McKay, the Jones Professor of Hydrogeology and head of the Department of Earth and Planetary Sciences, had been called upon by the Electric Power Research Institute, Nuclear Regulatory Commission, and Tennessee Valley Authority for help in flood risk analyses. As manager of the multi-university effort, McKay and fellow researchers, which include geography’s Sally Horn and Henri Grissino-Mayer and anthropology’s Howard Cyr, are aiming to figure out if certain methods can help predict river flooding near power plants in the eastern United States. The goal is to avoid what happened in Fukushima, Japan in 2011.

“The tsunami flooded the power plant which caused failure of the auxiliary power and cooling systems, leading to a partial nuclear meltdown and release of radioactive elements to the environment,” explained McKay. “Nuclear power plants in the interior of the United States are typically located on major rivers or lakes, which may be susceptible to damaging floods. We need to know the risk of rare, but very large floods for rivers, like the Tennessee, where nuclear power plants are located.” Right now, the real risk for floods of power facilities in the eastern part of the country is not known because records have only been kept for the past hundred and fifty years or so. And, for power plants, that’s not enough.

“A thousand-year flood has a one in one-thousand chance of occurring any given year. That goes well beyond our monitoring records, but could occur at any time and do a lot of damage,” said McKay. “To help assess this risk, we need to determine records of river flooding going back many thousands of years, rather than a few hundred years.”

McKay and his colleagues can peer back into prehistoric times by identifying buried flood deposits, high water marks, and other indicators such as damage to trees from flood debris. When this ancient flood data is combined with measurements of when the flood occurred drawn from age-dating methods, the researchers can construct a long-term record of flood occurrences.

This data will then be handed over to engineers who will construct models—that take into account changes to the landscape such as farmland or cities predict the probability of major floods in the future.

The project is still in the feasibility stage but, if deemed effective, these investigative approaches will likely be carried out throughout the eastern United States to determine flood risk at other power facilities. Power companies will then use this information to reinforce their plants with appropriate measures such as higher containment walls or elevated back-up power systems potentially saving the country from a life-threatening, economy-crippling catastrophic event.

This project is just one example of the impact of McKay’s work. Over the past twenty-three years, his research in hydrogeology has helped government agencies and industry deal with many environmental problems. These include cleaning up contaminated soil and groundwater at federal nuclear facilities, industrial sites, and even an ammunition manufacturing site in Tennessee. He has also investigated problems with microbial contamination from agriculture or human waste that can impact wells, springs, and streams in Tennessee and Bangladesh.

McKay takes a very practical approach to research and education. He calls himself a problem-solver who teaches his students to be problem-solvers, too, while preparing them for the job market.

“I’m interested in what I can do to help the community and society benefit from what we do at the university. I also want to do what I can to help my students become more successful,” shared McKay, who says his priorities reflect those of land-grant institutions like UT.

These priorities are evident in the types of classes he teaches which include career planning courses for both undergraduate and doctoral students. He recently received funding from the National Science Foundation to help community college students successfully transfer to geoscience programs at UT. The goal of the project is to develop methods to improve student success and ultimately prepare Tennessee students for career opportunities in high growth areas like geology and environmental science.

McKay’s pragmatic approach to research and education was strongly influenced by his family background. He comes from a long line of blue-collar workers and builders. His grandfather was a carpenter, his dad a pipe-fitter, and his brothers all work in construction. He says he does the same thing, just in an academic setting, helping others build a better world.

“I’m just a regular guy who likes to build things.”

And some of those things involve helping build a better future for our students, by preparing them to fill important jobs in this country.

– WHITNEY HEINS