"…IF palmetto is growing naturally on a piece of land, that land IS prone to flooding… By how much, who knows without a little research, but it WILL FLOOD. You just take a walk down the Trinity River bottoms anywhere and look at all the palmetto and then walk up a hill or just a small hammock and all of a sudden the palmetto stops… it's pretty easy to see. You won't see palmeto growing naturally up on the river hill. It will stop where the grade level water table stops. Ain't no way I'd buy a piece of property that I intended to build on that has palmeto growing on it unless I planned some serious build up of the land or build on piers… tall piers…"
https://www.texasbowhunter.com/discussions/forums/forum/topics/around-the-campfire/630763-palmetto-palms-low-land