In your story on the Permanent Canal Closures and Pumps project in New Orleans (ENR 5/9 p. 24), with regard to the severity of Hurricane Katrina’s storm surge in Lake Pontchartrain, wave heights were typically similar to those assumed for the design of the structures (IPET, vol. 1, p. 2). The U.S. Army Corps of Engineers had designed for surge heights of about 12 ft, and the estimate of Katrina’s storm surge along the drainage-canal frontage was about 11 ft. Therefore, the three catastrophic breaches that occurred within the 17th Street and London Avenue drainage outfall canals represented failures of the system to meet design objectives (IPET, vol. 1, pp. 40-41).

The second sentence of the story is technically incomplete. The London Avenue Canal breached on both sides, not just one side. These two breaches, combined with the breach of the 17th Street Canal, flooded the portion of New Orleans with the most people, property and infrastructure.

The failure of the Corps levee system during Katrina caused mass drownings and altered the lives of more than 1 million people. We owe it to the survivors to tell the story correctly.

New Orleans


Editor’s Note: The ENR story has been updated online to clarify impacts related to the failure of canal floodwalls during Hurricane Katrina in 2005.