Engineers were this week watching to see whether US Army Corps attempts to stem the floods from the Mississippi River would give enough protection to densely populated areas.
The Corps has opened floodgates and blown up more levees along the Mississippi River, sacrificing farmland and smaller communities to protect the densely populated cities of New Orleans and Baton Rouge.
Residents were told to evacuate their homes and head for higher ground.
The most significant event was the opening of the Morganza spillway in Louisiana. Officials opened two of its 125 massive gates on Saturday and another two Sunday.
Saving New Orleans
The move was intended to divert water away from heavily populated New Orleans, Baton Rouge and chemical plants and oil refineries along the lower reaches of the Mississippi − easing pressure on levees there.
It is hoped this will prevent potentially catastrophic floods.”There’s not much more they can do,” said Arcadis Global Knowledge Network of Water Management director and professor in Urban Water Management at the Rotterdam University of Applied Sciences Piet Dircke.
Dircke has also been part of the Arcadis team that has so far earned £250M for its work on the Hurricane and Storm Damage Risk Reduction System built following the devastation caused by Hurricane Katrina in 2005 (NCE 2 September 2010).
The new system was due to open this summer in time for the hurricane season but the latest flood threat has thrown the opening schedule into doubt.
It was designed primarily to create protection from storm surges from the Gulf of Mexico. But the latest threat to the region is inland.
The Corps has also taken more drastic steps to prevent flooding on the Mississippi. Further north, Engineers blew up a levee in Missouri − destroying about 100 homes − to take the pressure off floodwalls protecting the town of Cairo (News last week).
The hope is that sacrificing the levee could reduce the water levels at Cairo by about 1.2m in less than two days.
Potential ‘6m depths’
It will be at least a week before the Mississippi River crest arrives at the Morganza spillway and floodwaters spill over into the Atchafalaya River basin. The waters could reach depths of 6m in the coming weeks.
Dircke said that the levees along the Mississippi are “very, very strong” and had performed well in the past, stressing that the latest river levels have in places surpassed those that were seen in the devastating floods of 1927. “It’s so far so good,” he said.