Protecting against the Next Katrina; November 2005; Scientific American Magazine; by Mark Fischetti; 2 Page(s)

In the aftermath of Hurricane Katrina's devastation, the nation has vowed to rebuild New Orleans and Gulf Coast communities while improving protection against raging storms. But before engineers redesign a single levee, they must consider a fundamental question: Can the Mississippi Delta be restored as a lush, hardy buffer that can absorb surges and rising seas? Or is it too far gone, necessitating a 300-mile wall to hold back the Gulf?

Researchers have known for at least five decades that wetlands help to stop storm surges from crashing inland. But for a century, the U.S. Army Corps of Engineers leveed the Mississippi River to its mouth to stop annual floods. That spared New Orleans but starved the wetlands south and east of the city of the sediment, nutrients and freshwater they need to thrive. The levees also cut off sediment flow that builds barrier islands ringing the delta.