"We kind of want it to happen overnight, or I do, but it's going to take some time," White House coordinator Don Powell said in an interview with Associated Press reporters and editors. "This could be five to 25 years for it all to fit into place."
Powell added: "It's been a bottom-up process and it's complex."
He said that much of what's needed for the return of New Orleans' population is "out of our control," including housing, ensuring safety and robust investment by the private sector.
Much of the economic rebirth hinges on flood maps that will set safety standards for rebuilding, Powell said.
The four parishes that make up New Orleans and its immediate suburbs have been waiting for the Federal Emergency Management Agency to issue the flood maps for months. Powell said he expects FEMA to release the maps soon, but that the data largely is tied to new levee cost estimates that would nearly triple earlier projectionsto $6 billion _ for protecting the city.