A good account in today’s Wall Street Journal of the difficulties involved:
The most serious breach was on a concrete floodwall along the 17th Street Canal, located on the border of Orleans and Jefferson parishes. Yesterday, the breach widened to roughly 300 feet from 200 feet. An attempt Tuesday to breach the gap by dumping 3,000-pound sandbags onto it failed. Outside engineers said that wasn’t surprising.
“It’s difficult to do, while the flood’s going on,” said Gary Guhl, a senior engineer with PBS&J, a Miami-based engineering firm. “Usually when it’s breached, you just let it go. When it breaches, that water’s coming through so fast it doesn’t do any good to push things in it…”
Efforts to repair the 17th Street Canal breach appeared complicated by a patchwork of government agencies responsible for different portions of the flood-control system. In Orleans Parish, for example, which includes the city of New Orleans, the Orleans Levee District — a state arm — has responsibility for management of the levees, while the Sewerage and Water Board of New Orleans oversees the pumps and drainage canals. The federal Army Corps of Engineers, which is helping to coordinate emergency response, built many of the levees and inspects them periodically, but typically isn’t responsible for their ongoing operation. Some levees in the New Orleans area were built and are owned privately or by local levee districts.
Late yesterday, Col. Wagenaar said plans to drop giant sandbags onto the 17th Street Canal breach have been abandoned because additional equipment needed to complete the operation had not yet arrived.
One problem was a lack of “slings” used to carry the materials by helicopters. The slings, which drop into the breach along with their cargo, can only be used once, and no one in New Orleans had enough to mount a sustained operation. Yesterday, an additional 250 slings that were to have been procured by state authorities were still sitting at the Baton Rouge airport, Col. Wagenaar said.
Army Corps officials were moving ahead with a plan to close off the canal early today by driving huge sheets of metal into the base of the canal and stop the flow of water. The corps overruled local officials’ objections that the approach might impede efforts later to pump water out of the canal. “Right now, we’re going to move ahead and fill the canals,” Col. Wagenaar said. “We cannot wait. We have to shut these canals off.”