NEW ORLEANS – New Orleans’ mayor has the authority to let residents return to his hurricane-damaged city, but the Coast Guard official in charge of the federal disaster response said yesterday that all the information from health and environmental experts recommends against it.

Coast Guard Vice Admiral Thad Allen plans to meet with Mayor Ray Nagin today and develop what he called a logical plan to repopulate the city.

If Vice Admiral Allen gets his way, that repopulation won’t start today, as the mayor planned, but it will be soon.

“I wouldn’t want to attach a time limit to it, but it includes things like making sure there’s potable water, making sure there’s a 911 system in place, telephone, a means to notify people there is an approaching storm so you can evacuate it with the weakened levee situation,” Admiral Allen said on NBC’s “Meet the Press” yesterday.

“We can do that, and we can do that fairly soon, but it’s very, very soon to try and do that this week,” he said.

Mr. Nagin didn’t appear ready to back down Saturday as he defended his plan to return up to 180,000 people to the city within a week and a half despite concerns about the short supply of drinking water and heavily polluted floodwaters.

“We must offer the people of New Orleans every chance for a sense of closure and the opportunity for a new beginning,” he said.

He wants the Algiers, Garden District, and French Quarter sections to reopen over the next week and a half, bringing back more than one-third of the city’s half-million inhabitants, though city officials have backed off a specific date for reopening the famous French Quarter. The areas were spared the worst of Hurricane Katrina’s flooding.

Mr. Nagin said his plan was developed in cooperation with the federal government and balances safety concerns and the needs of citizens to begin rebuilding.

But Admiral Allen said he had spoken personally with the administrator of the Environmental Protection Agency and the director for the Centers for Disease Control and Prevention and returning now wouldn’t be advised. A prime public health concern is the tap water, which in most of the city remains unfit for drinking and bathing, he said.

“We really support his plan to restart New Orleans,” Admiral Allen said. “We are right in sticking with his vision. It’s a matter of timing and creating the, enabling the structures that will allow us to do this safely.”

Those structures would include an evacuation plan if another storm hits the region and threatens an already delicate levee system, he said.

There are also still bodies to be recovered. Admiral Allen said over 90% of the primary house-to-house sweep was complete, but some homes are still under water and searchers will have to return.

Yesterday, the death toll in Louisiana increased by more than 60 to 646, according to the state Department of Health and Hospitals. That raised the total Gulf Coast deaths linked to the hurricane to 883.

Despite floodwater remaining in some areas and a lack of residents in the city, business owners were allowed back in to some sections of the city to begin the long process of cleaning up and rebuilding, part of Mr. Nagin’s plan to begin reviving the city by resuming a limited amount of commerce.

But confronted with damage that could take months to repair, many said hopes for a quick recovery may be little more than a political dream.

“I don’t know why they said people could come back and open their businesses,” said Margaret Richmond, owner of an antiques shop on the edge of the city’s upscale Garden District that was looted. “You can’t reopen this. And even if you could, there are no customers here.”

The Wal-Mart store in uptown New Orleans, built within the last year, survived the storm but was destroyed by looters.

“They took everything – all the electronics, the food, the bikes,” said John Stonaker, a Wal-Mart security officer. “The only thing left are the country-and-western CDs.”

Meanwhile, the city’s health care facilities have been shattered to an extent unmatched in American history, and its hospital system faces grave challenges as residents begin returning, the vice president of the national hospital accreditation organization said yesterday.

The official, Joe Cappiello, said several hospitals were probably damaged beyond repair by Hurricane Katrina, while some may try to rush back into business before conditions are safe. Others, while rebuilding, may lose doctors and nurses to communities elsewhere.

He also recounted harrowing details of how doctors and nurses felt compelled – against the fundamentals of their training – to make triage-style choices during the flood. They were forced to aid some patients at the expense of others with less chance of survival.

“Essentially the health care infrastructure of New Orleans is gone – it no longer exists,” said Mr. Cappiello, who just completed a three-day mission to the city along with a colleague from the Illinois-based Joint Commission on Accreditation of Healthcare Organizations.

Although the city has more than a dozen hospitals, none have resumed normal operations. Officials at Children’s Hospital, which Mr. Nagin had hoped would be ready when residents are allowed to return to the Uptown neighborhood this week, said they may need 10 more days to prepare.