Dec 24, 2013 2:45 PM by AP
BAYOU CORNE, La. (AP) - The levee around the 26-acre Bayou Corne sinkhole has cracked during a wave of underground micro-tremors, for the second time in less than two months, Assumption Parish officials say.
It's in the same place the earth-and-limestone levee sank a bit and cracks developed in late October. Those were repaired.
The levee was built to keep the salty and sometimes oily water out of surrounding freshwater swamps after a salt dome cavern operated by Texas Brine Co. collapsed deep underground and the sinkhole developed in August 2012.
It's now oval, with growth zones moving northeast and southwest, toward Louisiana Highway 70 and the Bayou Corne waterway.
Texas Brine documents filed with the state Department of Natural Resources don't suggest the sinkhole will reach either. But they say it is edging closer to the southern levee just north of Bayou Corne.
John Boudreaux, director of the parish Office of Homeland Security and Emergency Preparedness, said Monday that a new hairline crack showed up Sunday at the site of the largest crack from October. That crack had been about a foot wide before it was repaired.
The new crack had spread from a few feet on the levee top on Sunday to all the way across it by Monday, he said.
A second crack has formed along the inner side of the southern levee where the previous round of tremors had caused the levee to sink. Its shape suggests a small section of levee top may slide into the sinkhole, Boudreaux said.
Since last week, micro-earthquakes have been increasing near the sinkhole and the failed Texas Brine cavern, halting work on the sinkhole and totaling 180 per day by Sunday.
Texas Brine told DNR earlier this month the company plans to keep maintaining the levee with fresh material after cracking or subsidence happens. Company officials have also pointed out the sinkhole is moving toward stabilization, though the timeframe for that remains uncertain.