For those families and businesses not in flood plains, I wish them the best. For those in flood plains, I hope they have flood insurance and wish them the best as well, but I think they really need to understand the inherent perils of living where they live and consider relocating to higher ground for their own safety and peace-of-mind.

I know nothing about LA building codes, but I would hope it incorporates Federal standards which require new construction or major rebuilding to be raised above flood stage and that your client, the insurers, or Federal flood insurance will pay for that added construction cost.