Drought causes cracks in Mississippi levees

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Drought causes cracks in Mississippi levees

By MIKE DUNNE Advocate staff writer

South Louisiana's drought has done more than wilt plants -- it has helped crack the levees that hold back the mighty Mississippi.

The cracks included a mile-long fissure in the Donaldsonville area. The known cracks have been or are being repaired by filling them with clay.

The U.S. Army Corps of Engineers, which helps maintain the levees, said there is no cause for concern, even if hurricane season just began Friday.

"The drought has caused cracks to appear in some places, but they are only superficial and pose no danger of levee failure," said Bill Caver, geotechnical chief for the New Orleans District of the Army Corps of Engineers.

All of south Louisiana is classified as being in drought. Rainfall in Baton Rouge is about 11 inches below normal since the first of the year.

Caver said the Corps is concerned that drivers speeding atop the Mississippi River levees might be injured by encountering cracks along the edge of the crown.

"Some people think nothing of driving 50 or 60 miles an hour on the crown of the levee. At some locations, the river levees have cracks just big enough for a tire to drop in and flip the vehicle," Caver said.

In Plaquemines Parish, clay was used to fill a 1.5-mile-long crack just below Port Sulphur.

No fill has been needed for the Corps' hurricane-protection levees. The cracks in those levees are small enough that a good rain would close them up, Caver said.

"We design levees for all conditions. Our designs are shaped to deal with droughts that are far worse than this one," said John Grieshaber, chief of the Structure Foundation Section of the Geotechnical Branch.

The New Orleans District has 961 miles of levees in the Mississippi River and Tributaries Project, including 449 miles in the Atchafalaya Basin. The district begins below Natchez, Miss., and generally covers the lower half of Louisiana.

The district also has 340 miles of hurricane-protection levees, most of them in the New Orleans area.


-- Martin Thompson (mthom1927@aol.com), June 03, 2001

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