New Orleans' 9th Ward is protected from hurricane storm surges by the 26-foot-tall Lake Borgne surge barrier, but a scour hole has been discovered 27 feet below sea level and needs to be fixed.
NOLA.com reports the state and levee authority think the scour hole is due to a design error when the Army Corps of Engineers had the concrete levee built after Hurricane Katrina. However, the barrier is now under the authority of the Louisiana Coastal Protection and Restoration Authority, which could be responsible for the repair costs if the Army Corps doesn't pick up the tab.
Officials say there is no immediate risk of failure but "Without taking any corrective action, the scour hole could increase in size, depth and width, which in turn could subject the floodwall to potential structural damage," said a March 17 corps engineering assessment.
Last week, the Corps activated Phase 1 flood fight procedures because the Mississippi river at the Carrollton gauge in New Orleans had risen above 11 feet. Phase I is a proactive measure that's triggered when the Mississippi River reaches 11 feet and is forecast to continue to rise. The increased patrols help ensure the Corps' ability to respond quickly to any problem areas that may develop along the levee system because of the elevated water levels. Heavy rains upriver have caused the river to reach flood stage for the first time this year. April and May are peak months for flooding.
What will it take to fix the scour hole? Well, Lord willing and the creek don't rise, once the two agencies agree on who will pay for the work, the Army Corps has a five step plan to restore the barrier's structural integrity.
For how they'll do it and additional pictures, click here for the Times-Picayune story.