Regarding questions about the levees in New Orleans:

We should not have any major problem with Humbertos rainfall. We are experiencing some ongoing bands of rainfall at this time. Winds are fairly mild.
Our biggest need for the levees is to keep storm surge out of the city from the lakes, Mississippi River Gulf Outlet Canal, and marshes. Part of the levee system keeps river flooding and storm surge heading up the river from the gulf at bay. You are correct in your assumption that rainfall can be a problem. Since we have constructed ourselves into a "fishbowl" surrounded by these levees, rainwater has no place to go. We are crisscrossed by numerous canals which run towards Lake Pontchartrain. We have numerous large pumps which expel water into the lakes. As a rule of thumb, these pumps can adequately pump-out about 1-inch of rain for the first hour of rainfall, and about 1/2-inch of rain per hour therafter. Any rainfall in excess of these numbers does create backups in the canals and results in street and house flooding in certain low-lying areas. Pumping capacity has been reduced in two of the canals which have now been sealed at the mouth where they meet the lake. (Canals which breached during Katrina). There is some concern that too much water in the weaker repaired canals could cause some degree of failure if water levels are allowed to get too high in those canals. I do not forsee a problem in this particular storm event, but my canoe is always nearby just in case!