Government and independent engineers disagreed when pressed by a U.S. House subcommittee on whether levees are safe enough for residents to rebuild in areas struck by severe flooding during Hurricane Katrina.

Army Corps of Engineers Col. Richard Wagenaar stressed that the levees ringing the metro area now are significantly stronger and in some cases higher than what existed before Katrina hit Aug. 29.

He told lawmakers without hesitation that he would return if it was his home in the area, but others questioned him, saying that the levees have yet to be tested.

"I think the Colonel is a bit optimistic," said Dr. Gordon Boutwell, with the American Society of Civil Engineers.

Boutwell said he would move back to any part of the city above sea level "in a flash," but would wait until the repaired levee system protecting the area was tested by a future storm before rebuilding in lower areas.

U.S. Rep. Charlie Melancon hosted the House Committee on Science field briefing on Thursday, aimed at providing Congress an update on the status of flood protection projects across south Louisiana, as well as progress on a Corps report outlining recommendations for future projects that officials believe will be needed to ensure long-term safety.

Wagenaar said that according to new flood maps provided by the Federal Emergency Management Agency, about 75 percent to 80 percent of levees and flood walls will have to be built higher by several feet. He said all of that work should be completed by 2010.

So far, Congress has authorized the Corps to spend about $5.7 billion (euro4.48 billion) to complete that work.

However, officials from coastal areas lamented that Congress had yet to show backing for billions of dollars (euros) of additional money that would be needed to restore eroding coastal wetlands and barrier islands as well as to build new flood gates and backup levee rings that would give residents and private investors confidence to rebuild old communities.

U.S. Rep. Sheila Jackson Lee, a Texas Democrat, said she would urge Congress to reset priorities and help Louisiana get the money and technical expertise needed to improve its flood defenses.

"We must do it. There is no excuse. We're not living in the 1800s or the 1900s. We're living in the 21st century," she said. "We can protect this community."