Floodgate Pumps Still Vibrating in New Orleans, But Some Are Usable

All 34 pump motors that Army Corps of Engineers contractors installed in New Orleans’ 17th Street, Orleans Avenue and London Avenue canals have been rebuilt, but retesting over the weekend showed that many of them are still vibrating at unacceptable levels.

“We’ve not totally solved the problem,” corps pump specialist Jim St. Germain said, “and we’re continuing to work with the pump manufacturer and the motor manufacturer to help us determine what’s going on.”

Performance has improved enough at the 17th Street Canal, however, that St. Germain said the first six pumps installed there could be used to help move water out of the big canal if the new floodgates had to be closed to block storm surge from Lake Pontchartrain.

In another bit of good news for New Orleans and East Jefferson neighborhoods that drain into the canal, corps officials have just raised the so-called “safe water” level in the 17th Street Canal from five to six feet. That came after a reanalysis of data by the corps and independent specialists indicated that the canal, where floodwalls breached during Hurricane Katrina, could safely handle a little more surge.

“That would allow the gates to remain open longer, and it would allow them to be raised sooner,” said Paul Floro, spokesman for the corps’ Hurricane Protection Office.

The appropriate water level at London Avenue Canal is still being re-evaluated, but it could drop a bit below its current five-foot mark, said Walter Baumy, the corps’ chief engineer in New Orleans.

“We’ve done a lot of additional borings and independent analyses, and we suspect that it could go lower. We’ll make a decision by the time it has to be made,” he said. “And if it does go lower, we’re looking at how to mitigate that.”

Although most public attention since Katrina has focused on the 17th Street Canal, Baumy said protecting the London canal from surge is more problematic because sand layers are closer to the surface there and seepage – with potentially catastrophic results – is a threat.

St. Germain would not predict just where London’s safe water level may ultimately be established, but he cautioned the public not to read too much into a foot or half-foot of change either way.

“It’s good that the 17th went up a foot, but if London does go down, I wouldn’t get too excited. We’ll use the best technology we have in determining when to close those gates, but it isn’t exact,” St. Germain said.

Only the specifics of each storm, including the rate of rise in the water level of Lake Pontchartrain and each canal, would suggest when gates should be closed.

Information from: The Times-Picayune, www.timespicayune.com.