Risk-Based Strategy Changes Focus of Flood Prevention
It is going to take a risk-based strategy on the federal, state and local levels to provide hurricane and flood protection in New Orleans and mitigate risk associated with disasters nationwide.
“We are looking at a multihazard approach, multiple lines of defense and nonstructural methods, such as emergency preparedness for mitigating risk,” said Earthea Nance, New Orleans' first director of disaster mitigation planning, at last month’s annual meeting of the American Water Resources Association, in New Orleans. “The traditional disaster-protection paradigm is predicated on a strong federal role and a diminished local role. In New Orleans that resulted in an exaggerated reliance on the levee system and flawed settlement patterns.”
“I no longer talk about protection,” said Lt. General Robert Van Antwerp, chief of the U.S. Army Corps of Engineers. “I talk about mitigating risk. The New Orleans system is really a risk-reduction system, which is not all structural.”
“There is no such thing as being completely safe,” added Dennis Kamber, senior vice president of Arcadis, Rockville, Md., repeating a mantra from the Interagency Performance Evaluation Taskforce, which investigated Hurricane Katrina and produced the strategy of mitigating risk. “The public should not be misled. There is always residual risk and it must be communicated and managed.”
Post-Katrina New Orleans continues to be the ideal classroom for lessons about communicating and mitigating risk, as well as a systems approach to water management, said Garret Graves, director for the Governor’s Office of Coastal Affairs in Louisiana. Two-thirds of the U.S. drains through south Louisiana, which provides roughly 20% of the nation’s seafood and oil. The state is home to five of the top 12 ports in the nation, and the Port of New Orleans and the Port of South Louisiana together account for 20% of U.S. commerce.
From 1930 to 2000, Louisiana lost about 1,875 sq miles of land. The estimated annual loss is 24 square miles; 217 were lost in the 2005 hurricane season. Under the Coastal Protection and Restoration Authority, state officials are working to finalize the Comprehensive Master Plan for a Sustainable Coast, to maintain economic viability while protecting natural resources.
Using Louisiana as an example, the Corps has committed to a nationwide comprehensive watershed management and systems approach. “We can no longer look at individual projects but have to look at systems,” Van Antwerp says.