US engineers are working on plans install two flood control barriers to protect New Orleans from devastating storm surges, it emerged this week.
The plan for tidal gates similar to London's Thames Barrier is just one of three proposals being worked up to protect New Orleans from future hurricanes by the US Army Corps of Engineers.Army Corps project manager Greg Miller said: 'We would look at building a series of levees and tidal gates along the Rigolets and Chef Menteur, which are tidal channels that go from Lake Pontchartrain to the Gulf of Mexico (see map).'During a storm the gates could be shut to stop winds pushing water from the Gulf up onto New Orleans.'This is exactly what happened last year when Hurricane Katrina sent a storm surge into Lake Pontchartrain and up New Orleans' canals, breaching the levees and flooding the city.The Rigolets flood barrier, the larger of the two structures, at 244m would be less than half the length of the 520m Thames barrier and would have to withstand storm surges at least 10m high, said Miller.His team, which is working with consultant Royal Haskoning, is also looking at the upgrade of New Orleans' entire hurricane protection system to withstand a category five storm by 2012.The team is also considering restoring the Gulf Coasts naturally protective wetlands. It will present its conclusions in December 2007.Since Katrina the Army Corps has spent £440M improving flood defences since Katrina. A large proportion of the money has gone on steel floodgates on each of New Orleans' canals. However, low pumping capacity on the canal side of the gates means that in heavy rain the city could still flood as the water cannot be pumped into the lake fast email@example.com