Still reeling in the wake of the BP oil disaster, New Orleans is approaching the fifth anniversary of Hurricane Katrina on Sunday. The city has replaced almost all its levees, moved and upgraded pumping stations, written new evacuation plans for the most vulnerable residents, and is now well prepared to withstand another 100-year storm like the one that hit five years ago.

New Orleans now hosts 354,850 residents, almost 78 percent of its pre-Katrina population. At the same time, the city has become significantly whiter since the storm: It is now only 60 percent black, compared to 67 percent black, pre-Katrina. And many of the poorer black people who left town after the storm have yet to return.

New Orleans has gone through a boom while other cities have suffered during the recent recession. The number of poor people living in Orleans Parish has halved to 68,000 over the last five years, with median household incomes rising to $47,585 — just as household incomes declined nationally over the same period. There is a healthier share of middle-class families in downtown New Orleans.

But these statistics are largely a result of poor people leaving the city after Katrina and not returning. And there’s a growing divide in the greater New Orleans area between those who have benefited from the city’s recovery and those who haven’t. For example, there are now 93,000 people living in poverty in the six surrounding parishes around New Orleans, and there is a growing disparity in income in the greater New Orleans area, with African-Americans earning 44 percent less, and Latinos earning 25 percent less, than whites.

Does New Orleans’ newfound livability for young white families come at the expense of the poor black families who made the city their home before the storm?

“By most measures, it’s quite clear that the 100,000 people who are missing are the poorest and darkest former residents of the city,” says Rachel Luft, professor of sociology at the University of New Orleans. “And they are being replaced by a slew of YURPs, or young urban redevelopment professionals, who tend to be whiter, wealthier and better educated than the traditional residents of New Orleans. I think they’re being held up as the great white hope for rebuilding the city.”

The YURPs aren’t necessarily unwanted, and many traditional New Orleans residents are very grateful for their help — but their arrival, en masse, since Katrina has brought up some uncomfortable questions for the city, which is still struggling to set goals for its long-term recovery after Katrina. Especially with the demolition of federal housing projects, which once housed many of the city’s poorer African-American residents.

In the racist words of Davis McAlary’s Uptown mother in the HBO show “Treme,” many Uptown residents felt that a certain “element” had been excised from the city after Katrina. Whether the result of a deliberate conspiracy or simply inept efforts by federal, state and local government to counteract prevailing socioeconomic forces, the result is that certain other “elements” are now coming to dominate New Orleans’ political, cultural and social life.

Michael Ripski and Morgan Carter bought a double shotgun house on the border of New Orleans’ Irish Channel and Uptown neighborhoods for just over $300,000 in April 2010. The house, which was originally two houses, was built in 1902 and renovated into a single home in the last few years. It’s spacious and immaculate inside and out, with fresh paint on every surface and a vintage charm that might fetch millions in other real estate markets like Brooklyn, N.Y., or San Francisco.

Ripski, a Brown University graduate, first came to New Orleans in 2002 to work for Teach for America, then left for graduate school just before Katrina and returned in May 2009. A psychologist, he is now the director of school support for the Achievement Network, a nonprofit founded in Boston in 2005. Carter moved to New Orleans in summer 2007 after finishing a master’s degree in education policy at Stanford University.

“Professionally, this is most interesting place I could be,” says Carter. “And it’s the most fun place, and it’s a fun place to put down roots.”

Ripski and Carter also value the ethnic and socioeconomic variety in their neighborhood, and point out that their presence in the area has been positive.

“This house, actually, from what we’ve been told, was the neighborhood crack house 10 years ago,” says Carter. “It burned down, and they took it down to the foundation and rebuilt it with new electricity and plumbing.”

Both Carter and Ripski are originally from the South, he from Tennessee, and she from Texas, and they refute the suggestion that they might be modern-day New Orleans “carpetbaggers.” The term was given to Northerners by Southerners during the post-Civil War Reconstruction era between 1865 and 1877, suggesting opportunism and exploitation in the outsiders.

“I didn’t come here to do well professionally,” says Ripski. “I came here to help the children who were being done a disservice by a dysfunctional education system.”

“My interest has always been providing for the educational needs of all children,” says Carter. “And in New Orleans, there is a greater opportunity to effect change.”

Indeed, Katrina was the catalyst for reforming a failing public school system. Before Katrina, there was only one charter school in the city compared to the Orleans Parish School Board’s 120 public schools. Now there are 51 charter schools across the city, and only 37 traditional schools — with children doing better, academically. Most attribute the shift to a weakening of resistance to the charter school movement from unions, teachers, parents and certain legislators, after Katrina.

It’s one thing for New Orleans to attract a booming YURP population, but it’s another to try to keep such people once they arrive. Many young people have come to New Orleans for Teach for America, for example, and then left for graduate school or professional opportunities in cities like New York, Washington, D.C., and Chicago. Indeed, Nathan Rothstein, the co-founder and executive director of the now defunct nonprofit NolaYURP (former slogan: Connect. Retain. Attract), has since moved back to Massachusetts to go to graduate school for an MBA in nonprofit management. A year ago the nonprofit was holding benefits and fundraisers. Now its Facebook page and blog have gone without updates since early 2009.

“I moved this summer; I’m starting grad school,” says Rothstein. “I made a strong connection to the city, so I may be back. I don’t think people going to school and moving away for a year or two or five years, and then returning, is necessarily a bad thing. I understand how it looks, but I felt it was the right time for me to go to school.”

Rothstein says he feels good about how people he met in New Orleans have made connections and are now networking in New Orleans and around the country.

“As a 23-year-old starting the organization, I did it without any experience, but then to continue doing that kind of work I felt that this kind of degree would be right for me,” he says. “No school in New Orleans really focuses on nonprofit management.”

Rothstein also says that while New Orleans failed to “connect, retain and attract” him, personally, “the important thing is that people who would have never been exposed to New Orleans spent time there and are now ambassadors for the city, wherever they go.”

After Katrina, former real estate agent Leslie Jacobs founded 504Ward, a nonprofit named after the city’s phone prefix, to try to stop the “brain drain” she saw in New Orleans. 504Ward produces a newsletter and puts on regular restaurant nights and gatherings for its majority white membership.