The levees and flood protection were only slightly tested by Katrina. The Mississippi River levees held or the westbank would have been inundated. The Intercoastal Waterway and  Harvey Canal levees held. Would they have held if the storm had passed to the west and driven the surge up Barataria and into the westbank?

Some areas of Algiers on on the historic high ground and offer the greatest possible safety. Build high, build strong.

The best protection for the whole area is miles of vibrant and flourishing wetlands to the south supplemented by some relatively modest levees. Twenty more Caernevon type projects could make this a reality.