It is still early to write about the effects of H. Isaac, but here is one positive story from HLSecurityWire: As Hurricane Isaac beats on New Orleans, new infrastructure is holding up; August 31, 2012. It is nice to know that a $14B federal investment was worthwhile.
This week, as Hurricane Isaac was threatening to replicate the physical damage that Katrina inflicted, it has become apparent that $14 billion worth of changes and improvements in infrastructure, planning, and emergency response procedures have given the city of New Orleans and the Gulf states the ability to withstand the worst of the storm.
See also this article on Sept. 2 in the CSM.
Recovery Diva 
NOLA faces fllooding threats from five causes. (1) Main Stem Mississippi; (2) Lake Ponchatrain; (3) Internal flooding and Drainage; This includes pumping failures or exceedence of design capacities; (4) flood surge up shipping canal downstream of NOLA; and MRGO!
The NFIP maps hydrologic events only not metrological events. ONLY about 10 inches of rainfall in NOLA and no where near the 24 hour, 36 hour, or 48 hour records for that area.