With the Mississippi River water level rising, officials are putting in place additional precautions aimed at preventing anything that could undermine area levees.
The river is now above 16 feet at the Carrollton gauge and is expected to rise to within a half-inch of its flood stage of 17 feet before water levels slowly fall in the coming weeks.
While not an uncommon occurrence, the high water level means more regular inspections along the levees to ensure there aren't any problems with them or any boats tied up to the protective system.
It also means no new holes can be dug within 1,500 feet of the levees, any existing ones need to be filled in, and pilings can't be driven in the area, said Bob Turner, director of engineering and operations for the Southeast Louisiana Flood Protection Authority — East.
Normally, that type of work requires a permit if it is near a levee. After the river reaches 11 feet, special waivers are needed for that work to continue. Once the water level reaches 15 feet, waivers are no longer granted.
Pile-driving near levees can cause vibrations that could weaken them.
Holes dug nearby can provide a conduit for water that normally seeps through the sand layer under the levees, Turner said. When that happens, the pressure of the flowing water can bore through the levee itself, creating a hole that then expands as more water flows through it, he said.
"It gets bigger and bigger and bigger and acts like a pipe," Turner said.
Inspectors have already found more than a dozen cases where crews were doing prohibited work, Turner said.
"In a lot of cases, people don't realize the river is up," he said.
Daily inspections along the levees have found signs of seepage, though that is not uncommon, Turner said.
So far, none of the areas experiencing seepage has had the cloudy water that indicates a problem, and there have been no signs of sand boils, cracks or other issues with the levees, he said.
WWNO-FM reported that the Corps does not expect to have to open the Bonnet Carre Spillway, which would let water from the river flow into Lake Pontchartrain. It said the National Weather Service expects the river to crest on June 2 at New Orleans.