What's the big deal? It doesn't look that bad considering its CAT4. Looks like the levee is holding up. Good.
It made landfall in a sparsely populated area but it'll be moving into more populated areas in the coming hours...it's just the beginning. New Orleans levee issues come more into play when a strong hurricane goes just east of the city like Katrina driving north winds from lake Pontchartrain into the city.
Levee issues also more pronounced when they neglected maintenance/upgrades for years prior to Katrina. Things should be better now. The system is supposed to be able to withstand something like this and prevent catastrophic flooding.
Houston needs more than that. Harvey was not a storm surge/Dike-preventable event. Every rainstorm that brings an above average amount of rain will cause flooding in Houston. The Dike/spine would protect Galveston in the event of a surge… but the island usually doesn’t see much flood damage from rain as things drain back into the ocean fairly promptly (as evidenced by minimal damage during Harvey).
the biggest focus, as I understand it, is protecting refineries and the port…protecting against an environmental disaster as a result of a massive storm surge. The predictions about that kind of event call it America’s Chernobyl.