I’m not in the area, but am pretty sure this flooding is well above sea level.
You are correct, but not in the "well above" part. BR is 17' above sea level but being as far inland as it is, it is remarkably flat. The Mississippi meanders there and has flooded the city several times, the worst of which was 1972 but roughly every 10 years it does so again, but its frequency is increasing, reducing that pattern to every 3-5 years. The State officials could open the Morganza spillway but have only done so a couple of times.