Total nonsense.
You could do the same job with pumps a quarter of the size if you just used four times as many. And so forth. The more pumps they use, the faster it will go.
Is the bottom of either Pontchartrain or the Mississippi lower than the ground in NOLA. If so, just get a million garden hoses and siphon that sucker out....
It's not nonsense. Have you ever been inside a New Orleans pumping station?