Lowlands expertise lifts New Orleans

It will come as a surprise to no one that Dutch engineering expertise in flood defence systems is being deployed in the continuing response to the destruction wreaked upon the American city of New Orleans by Hurricane Katrina.

The project involves planning and designing a wall that seals off the Inner Harbor Navigation Canal (IHNC) in New Orleans from the Gulf of Mexico. In the event of a hurricane, two navigation gates within the 3km wall can be closed to prevent water surging up the canal.

Royal Haskoning is providing guidance on various design elements including the height of the structure and the capacity to withstand the forces of hurricane induced waves. Experts from Royal Haskoning are also providing advice on how best to prevent soil erosion in the area and maintain navigation along the channel. Construction of the barrier officially started in December 2008 with dredging of the access channel.

During Hurricane Katrina, water levels breached the dykes and flood walls along the IHNC in several places.

‘Hurricane Gustav last September demonstrated once again how badly this surge barrier is needed, said Royal Haskoning project leader Mathijs van Ledden. ‘The water came right up to the top of this canal’s defenses, which are intended to protect a couple of hundred thousand people.’ The risk of flooding in the central part of the city will be significantly reduced after the surge barrier has been completed.

The New Orleans surge barrier must be able to protect the city against a 1% surge level that could reach 6m above sea level and significant wave action. Royal Haskoning has advised on using the storage capacity behind the structure for the overtopping to reduce the height of the structure, resulting in significant cost reductions.

Royal Haskoning has had an office in New Orleans since 2006 and, together with its American partners, was awarded a major project in 2007 by the Department of Water Resources to provide flood protection in and around Sacramento, California. Over the last year Royal Haskoning has also undertaken a number of flood protection projects for private and public sector clients in the New Orleans area.