Phoenix in the Swamp
Despite the obstacles, there's no shortage of rebuilding plans
[inset map labels]
New Orleans
New Orleans International Airport
Lake Pontchartrain
Community Haven: Downtown, Superdome, French Quarter
Industrial Canal
Lakefront Airport
Mississippi River
FLOODGATES
Floodgates like this massive construction in the Netherlands could be employed to protect a rebuilt New Orleans from storm surges. At least four locations (shown in red on the map) could use gates of various sizes.
[inset map labels]
River
Gate
Pivot
Storm surge
SUPERLEVEES
These enhanced levees hold up well under the forces of flooding. Japanese engineers are using them in Osaka City, among other places. If used in New Orleans, superlevees could support new neighborhoods, raised above sea level.
[inset map labels]
Mississippi River
Superlevee
Old levee
New development
Pre-Katrina neighborhood
RESTORING WETLANDS
River diversions and gated levees would allow sediment from the Mississippi to flow into wetland areas, replenishing the vanishing storm surge buffer. Proposed diversions would carry various amounts of water.
7,481-37,403 gallons per second
37,403-112,208 gallons per second
112,208+ gallons per second
The Mississippi River's extensive levees are designed to keep water and sediment from damaging development in low-lying areas. The water diversion projects would reconnect the Mississippi River to the delta.
One diversion path tracks Bayou Lafourche, the Mississippi's course 1,000 years ago. The other would require an artificial canal.
Proposals have been made to restore degraded and fractured marshland in widespread areas using dredged sediments pumped through pipelines.
Some suggest closing the Mississippi River-Gulf Outlet. It would then no longer be dredged, and the ensuing silt buildup would gradually replenish the wetlands of the Breton Sound.
This area is a potential site for a large marsh building diversion project.
Enhancement of this barrier island chain using available sand
Building a structure here [Head of Passes], perhaps a pair of gates still to be designed, could allow unimpeded shipping traffic while preventing the annual loss of 200 million tons of sediment. Trapping that sediment could help replenish this delta and save the yearly $50 million now spent on dredging.
Sources: Louisiana Coastal Area; Len Bahr, Governor's Office of Coastal Activities; Joseph Suhayda and Nedra Korevec, LSU; Scientific American; Japan Institute of Construction Engineering; Ministry of Transport, Public Works and Water Management, Netherlands
Rob Cady and Stephen Rountree-- USN&WR
Satellite imagery--Landsat, NASA
With Alex Kingsbury
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