Rusted Sky

Maybe there's something to be said for just stacking dirt like crazy to keep water out of a city...

Intricate Flood Protection Long a Focus of Dispute - New York Times

The 17th Street levee that gave way and led to the flooding of New Orleans was part of an intricate, aging system of barriers and pumps that was so chronically underfinanced that senior regional officials of the Army Corps of Engineers complained about it publicly for years.

Often leading the chorus was Alfred C. Naomi, a senior project manager for the corps and a 30-year veteran of efforts to waterproof a city built on slowly sinking mud, surrounded by water and periodically a target of great storms.

...

"A breach under these conditions was ultimately not surprising," he said last night. "I had hoped that we had overdesigned it to a point that it would not fail. But you can overdesign only so much, and then a failure has to come."

No one expected that weak spot to be on a canal that, if anything, had received more attention and shoring up than many other spots in the region. It did not have broad berms, but it did have strong concrete walls.

Shea Penland, director of the Pontchartrain Institute for Environmental Studies at the University of New Orleans, said that was particularly surprising because the break was "along a section that was just upgraded."

"It did not have an earthen levee," Dr. Penland said. "It had a vertical concrete wall several feel thick."

Done by the lowest bidder, of course... and I'd be surprised if there weren't some significant kickbacks involved. Maybe an outer sheath of decent concrete, and inside a slurry of sand and gravel, with just enough cement to make it look good? Or it could be that water washed over one section and weakened the support behind it - and once that failed other sections went like dominos. It's kind of funny that earthen levees would have more durability than a concrete wall.

Doesn't much matter now what caused it. They're going to try sealing off the canal, and when it's stabilzed then plugging the hole.

Good luck to them!

J.