A THAMES barrier-style flood defence is urgently needed to protect New Orleans, a report by US officials claimed last week.
A barrier on Lake Pontchartrain to the north of the city was listed as an 'urgent early action' in the Louisiana Coastal Protection and Restoration Authority's draft masterplan for a sustainable coast.
The report demands that a barrier is built to reduce New Orleans' dependency on levees as flood protection and to protect communities to the north of the lake that have little or no flood protection.
During Hurricane Katrina in August 2005, a storm surge sent water rushing from the Gulf of Mexico into Lake Pontchartrain and up New Orleans' canals, breaching levees and flooding the city (NCE 1 September 2005).
The need for a barrier to protect the area was raised by the US Army Corps of Engineers last year as part of its report on the long-term coastal protection needs for Louisiana, due for submission to the federal government this December (NCE 24 August 2006).
However, work on the barrier proposal has yet to reach a detailed stage and is regarded as a lower priority than the improvement of New Orleans' levees.
Determining the design levels of the levees and the flood protection system for a one in 100 year storm is the thing that is urgent, ' said Royal Haskoning Netherlands coastal and rivers business director Rene Zijlstra.
The Dutch consultant is working with Corps engineers to establish new design elevations for levees across New Orleans, which must be ready by the end of this month.
'From that they can start to design and construct the new fl ood protection system for the city that must be ready by 2010.
We will then look at the longerterm plan for Louisiana's coastal protection, ' said Zijlstra.
It is anticipated that the Corps' report in December will recommend that the US federal government approve up to £26bn investment over several decades to improve flood protection and restore Louisiana's outlying wetlands, which act as a natural flood defence.