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Even more troubling, water appears to be seeping under the stout new floodwall erected along the Industrial Canal to protect the Lower Ninth Ward.

The new wall sits atop steel sheet piles driven 20 feet (6 meters) into the ground. The piles are long interlocking wall sections that retain water and transfer pressure deeper into the ground, where the soil is more stable.

But water from holes in the canal bed, excavated before Katrina or scoured by the storm, may be seeping under the barrier through permeable layers of sand and silt.

The Army Corps counters that the source of the puddles behind the wall is likely a broken water main.

But Bea, who actually tasted the seepage to make sure it was slightly salty\ufffda sign that it was coming from the canal\ufffdsaid the wall could fail in the next hurricane.

Co-leader of a Berkeley team that investigated the Katrina levee failures, Bea is now serving as an expert witness in a multibillion-dollar class action lawsuit against the Army Corps of Engineers.

Doomed to Fail?

Bea is not alone in his criticisms.

A Dutch engineer recently visited some of the new floodgates and pumps installed at the mouths of the city's three main drainage canals. His verdict: They may be "doomed to fail" in the next big storm.

The engineer, who asked not to be named because he sometimes collaborates with the corps, noted that the gates have no mechanism to remove sediment and other debris that might keep them from closing as a storm approaches. Instead, the corps says it will rely on divers to check for obstructions and clear them away.

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