Statewide Groundwater Model Could Help Conserve Louisiana Resource
March 25, 2019
BATON ROUGE, LA – Working to save one of Louisiana’s most valuable resources, LSU Civil & Environmental Engineering Professor Frank Tsai is in the process of creating a statewide groundwater model that will enable future generations to conserve the state’s most precious commodity—water.
“Groundwater has a very strong economic value to Louisiana,” Tsai said. “We think we’re a water-rich state, so we can use all the water we want, and that’s the wrong concept. The groundwater model will help us estimate how much groundwater we have left. When this project is complete, Louisiana will be the only state in the nation to have a very detailed groundwater model.”
Tsai said that without proper groundwater management, the state’s economy would be greatly affected. Because Louisiana farmers use more than 50 percent of groundwater for agriculture, Louisiana residents could see high water and energy bills, less agricultural production, high food prices, loss of small businesses, outmigration of industries, and degraded communities.
“The two fundamental questions are how much groundwater do we use, and how much do we have,” Tsai said. “How much we use is the relatively easy part, because we survey and look into flow meters. However, water-use data is not accurate for farmers, because they aren’t required by law to report how much they pump. With a groundwater model, we will understand how much groundwater we have.”
Since Louisiana geology has many layers like clay and sand, groundwater must be estimated at every depth. A groundwater model would help calculate this, as well as show which direction the water is flowing, an important factor in avoiding water disputes with neighboring states.
“Groundwater has no political boundaries, so neighbors can take it from you,” Tsai said. “There is currently a water dispute case, Mississippi v. Tennessee, in the Supreme Court. This is why it’s important to build a model for policy and to measure.”
Louisiana’s groundwater supply is also affected by land subsidence and saltwater intrusion. The more water that is removed from the ground, the more the ground level drops. Subsidence, of course, leads to flooding and structural damage.
Saltwater intrusion is just as alarming.
“There is a geological fault along Interstate 10 in Baton Rouge that keeps shifting,” Tsai said. “The fault acts as a physical barrier separating fresh water from salt water. Salt water can also come from salt domes and salt basins, which are all over the state. Right now, people are pumping from shallow zones to avoid them. High salinity will kill crops. Industrial plants, which currently use very clean groundwater, will need to treat their water once they are forced to use surface water, like the Mississippi River. If salt water intrudes their wells, who is going to pay for that? It’s very expensive to treat surface water. Industry could be forced to move elsewhere, which could change the economic landscape of south Louisiana. It’s very scary.”
The National Institutes for Water Resources in conjunction with the U.S. Geological Survey has funded Tsai’s groundwater model project for the past few years. The NIWR provides annual funding to water resources research institutes in all 50 states and the four U.S. territories, including the Louisiana Water Resources Research Institute in LSU’s Patrick F. Taylor Hall, of which Tsai is the director.
Though Tsai has already been working on this statewide groundwater model project for five years, he is determined to see it through, which is no small feat.
“Before you develop the model, you need data,” he said. “To understand geology, you need well logs. There are more than 200,000 wells registered in Louisiana, and all of the information must be transferred from paper to digital spreadsheets, which requires lots of manpower.”
Tsai, who teaches groundwater and hydrology courses, designs a well log course project with more than 200 students working on digitizing data annually.
“When they type the data into spreadsheets, they learn and realize the geology of Louisiana,” he said. “It’s a lot of work without an end, but it’s fun because the data benefits Louisiana’s groundwater study. The mission for the LWRRI is to train future water scientists and engineers. We want to make sure our product can be used to solve water resource problems. That’s the main goal here.”
Contact: Libby Haydel