With an overflow crowd of more than 120 people, the Alpharetta City Council approved a project that promises to make a $600 million ornament out of a bankrupt eyesore.

The council voted unanimously late Monday to allow North American Properties to proceed with plans to turn the abandoned Prospect Park on Old Milton Parkway into an upscale, mixed-use development. The site, a failed dream of developer Stan Thomas, has sat idle for four years and has become a scar at the entrance to the city, with an unfinished parking deck and treeless, muddy furrows.

North American Properties plans to build an 86-acre development that will include roughly 559,000 square feet of retail, a 14-screen movie theater, restaurants, two hotels, office buildings, single-family homes and condos and 250 luxury apartments, which would sit atop retail buildings.

The apartment issue raised eyebrows earlier this month, when The Atlanta Journal-Constitution reported that a city-funded organization was lobbying the City Council for the zoning change. Residents who oppose adding apartments to the city’s inventory objected that their tax money was being used by an outside group to promote something they didn’t want.

Among council members, potential impact on North Point Mall was a concern.

Without writing it into the approval conditions, council members urged the company's managing partner, Mark Toro, to live up to his own claims that the Avalon development would not raid tenants from nearby North Point Mall.

Toro assured the council he has no intention of cannibalizing the nearby mall. However, requiring his company to reject offers from North Point tenants is "unfair, unconstitutional and un-investable."

But resident David Bristol told the council that cities have every right to use zoning conditions to protect their assets.

"I think if you say you're going to build something upscale, then bring in upscale," he said. "Don't go around trying to raid all the other people in town."

Many of the residents at the meeting were more concerned with the proposed apartments, which they said would add to the city's already high inventory. The city's Comprehensive Plan promotes a ratio of 85 percent for-sale dwellings to 15 percent rental properties. The ratio of rentals currently stands at 24 percent.

But North American Properties representative Richard Munger used the meeting to announce negotiations with another developer that would swap its allowance to build more than 200 apartments in exchange for commercial space at Avalon. The deal would essentially cancel out any net growth in rental properties in the city, he said.

That seemed to placate most residents.

Some, like Elizabeth Hooper, said they wanted to make certain the city capped the number of apartment units at 250.

While others, like Debra Dent, said apartments shouldn't be blamed for all of society's ills. They are an asset for newcomers looking to purchase a home, she said, and the Avalon units will be part of a major destination point in the region.

"I feel this development, Avalon, would be more of a ‘wow' than anything else that we've ever seen," Dent said.

With a completion date of October 2013, Avalon is expected to bring more than 1,000 temporary and 3,500 permanent jobs to the area and generate $21 million in annual sales tax revenue, North American Properties officials said.