What is this about? Given the depradations from flooding I would have thought both of these states had more ground water than they know what to do with, hence the periodic flooding.
I found a drawing that shows the state lines of AR, MS, TN and how they share in the Memphis Sands Aquifer
it also gives us this blurb:”the state of Mississippi claims MLGW wells have altered the flow of aquifer water, pulling more of it northward across the state line. Losing that suit could result in Memphis paying $615 million in damages and having to turn to the Mississippi River to get some of its water.”
https://www.commercialappeal.com/story/news/environment/2016/12/16/memphis-sand-aquifer-buried-treasure/93814278/
another hint and some background on the multiple lawsuits can be found here:
“Mississippi has also attempted to draw this distinction by presenting a “two aquifer” theory, suggesting that what is colloquially known as the Sparta Sands aquifer in Mississippi and Arkansas is structurally distinct from what Memphians call the Memphis Sands aquifer, when according to the USGS the two aquifers are hydraulically connected and refer to the same underground reservoir.”
https://undark.org/2020/09/07/memphis-aquifer-supreme-court/