NEW ORLEANS (AP) — A new report finds New Orleans’ population nearing 300,000, a milestone one demographer sees as significant in the city’s ongoing recovery from Hurricane Katrina.

But Greg Rigamer, whose GCR & Associates released the report and has been tracking post-Katrina demographics here, said he doesn’t expect the city’s population to rival, anytime soon, the estimated 455,000 who lived here before Katrina hit in August 2005.

Rigamer believes the city’s population, which has grown by an estimated 3,000 to 4,000 residents a month during 2007, likely will level off at around 325,000 to 350,000 in the next few years.

‘‘Unless things really, substantially change,’’ he said Monday. ‘‘When you look at the (available) housing stock on the market, it’s not a matter of housing, but whether we can support those who are back, both economically and from a service standpoint.’’

Mayor Ray Nagin has said 2008 will be a tipping point in a recovery that officials hope will gain momentum with the freeing up of additional federal aid and the flow of rebuilding grants to homeowners.

Progress has been sporadic, particularly in the hardest-hit neighborhoods, where one block can be peppered with rebuilt or work-in-progress homes and another marred by overgrown lots, empty houses and tire-busting potholes in the streets.

Rigamer’s report, based on utility hookups, estimates the population this month reached 65 percent of its pre-Katrina level, with roughly 295,450 people. Hitting 300,000 — a threshold he believes will soon be crossed and put New Orleans closer in size to cities like Pittsburgh and Tampa, Fla. — will be a ‘‘significant indication of New Orleans’ sustained viability.”

“ as a major city and as an anchor for a large metropolitan area,’’ his report states.

It also will be a big psychological boost, he said.

Practically every neighborhood has people back, Rigamer said, though it remains to be seen whether their numbers will be sufficient to support businesses in those pockets of the city.

Shawn Antee, who lives in the Gentilly neighborhood, said the population estimate is meaningless to him. What matters to him is the quality of available services, such as police and fire protection, health care and public schools, and he hopes to see improvements in all.

Still, he’s optimistic: ‘‘If we do what we should,’’ he said, ‘‘2008 should look good, and the future, 2009, 2010, should look a lot better.’’