With all approaches, it will take at least 15 years to realize tangible benefits on flood risk reduction from building new land. What sets our plan apart is that it also creates immediate significant reductions in flood risk for Delta communities. Opening new river mouths upstream of English Turn leads to a tremendous decrease in river height during flood events. This reduction in river water levels is essentially equivalent to making the existing Mississippi River levees through New Orleans 5 feet higher. Our surge relief channels on the Lower River result in a significant surge height reduction for Katrina-like events. As a result, Mississippi River levees through New Orleans would not need to be raised for river flood protection for many decades to come, and the replacement of the 85-year-old Bonnet Carré spillway (estimated to cost $500M) would not be needed.
Our approach takes the New Orleans area’s flood risk from 1 in 100 year protection to more than 1 in 1000. This reduces the risk of severe flooding over the next 50 years from 40 percent under the current system to less than 5 percent.