US engineers warn against New Orleans flood defence complacency

US engineers warned against complacency over the condition of New Orleans' flood defences this week after the city escaped with relatively minor damage following Hurricane Gustav.

The storm, which New Orleans mayor Ray Nagin had claimed would be more devastating than 2005's Hurricane Katrina, was downgraded to a tropical storm as it made landfall last week. It also  passed south west of the Louisiana town.

Although some flooding still occurred as levees were overtopped,  the US Army Corps of Engineers, responsible for the city's flood protection system, claimed its response to the storm was a success. Closed flood gates on the mouths of city's canals prevented water rushing into the city as it did during Katrina, and pumping stations quickly rid the city of what floodwater there was.

The American Society of Civil Engineers (ASCE) warned that the narrow escape should not allow a false sense of security to settle in.

"New Orleans still faces a higher level of risk from flooding than would be acceptable for many other engineered life-protection systems, and another Katrina-like hurricane is inevitable," read a statement by the ASCE's external review panel (ERP).

Its statement came  as it issued its final comments on the US Federal Government's Interagency Performance Evaluation Task Force's (IPET) analysis of Katrina's impact.

"The events of this week should shine an even brighter light on the need to continue improving the region's hurricane protection system, including the incorporation of risk into the decision making process at all levels."

The ERP, supported the government's assessment of the failures of New Orleans' flood protection system during Katrina but criticised what it saw as the unnecessary softening of IPET's conclusion.