Small correction in New Orleans flood control system: not 5½ feet of new protection - but, 6 inches!

A system of floodgates and pumps built since Hurricane Katrina to help alleviate flooding in several New Orleans neighborhoods may not be as much help as authorities first said.

Flood risk maps showed that the improvements made to the city canals’ drainage systems would reduce flooding during a major storm by about 5.5 feet in Lakeview and nearby neighborhoods. The maps were based on a storm that has the likelihood of occurring at least once in 100 years.

But in a report released November 7, Corps scientists estimated that the actual benefit the system would provide would be just 6 inches.

Does that qualify as an “Oops!” - or was the Corps of Engineers just hoping no one would notice?

The discrepancy was tucked into the voluminous report’s appendices, and neither the Corps nor the scientists hired to conduct the study brought the changes to the public’s attention when the report was released. It wasn’t until New Orleans television station WWL-TV asked an engineer involved in the assessment about the discrepancy that it became known.