Corps Scrambling to Plug New Orleans Floodwall Breaches
The day after Hurricane Katrina smashed into the Gulf Coast between New Orleans and Biloxi, leaving a path of death and destruction from New Orleans to Biloxi, the U.S. Army Corps of Engineers was scrambling to plug two floodwall breaches in New Orleans to stop water from Lake Ponchartrain from flowing into the city. Corps personnel from New Orleans, Memphis and St. Louis convened Aug. 30 with hydraulics engineers at Vicksburg District headquarters to confer with state and local officials and contractors on the ground in New Orleans to try to stem the inflow and close a 200-ft-long breach along the 17th St. Canal. �Water was pouring in from broken levees,� says Adam Wine, a U.S. Coast Guard spokesman, who flew over the city in a helicopter Monday. �There are some areas where the water was 25-ft deep.�
�We think the water overtopped the floodwall last night and scoured out the foundation, leading to a structural failure,� says Al Naomi, senior manager and head of the Lake Ponchartrain and hurricane protection plan. The top of the concrete floodwall , which sits atop an earthen levee, was 14-15 ft above sea level at the point of failure, Naomi says. The city is 6 to 10 ft below sea level at that point. Heavy rainfall from Katrina elevated Lake Ponchartrain�s flood stage to 5 ft above sea level, Naomi says.