A developer will be allowed to build a scaled-down version of Great Park in exchange for the right to construct thousands of homes in a deal that would appear to extinguish Irvine's long-running promise to give residents a municipal green space rivaling Balboa Park or even New York City's Central Park.

In a split vote, City Council members cleared the way early Wednesday for FivePoint Communities to build an extra 4,606 homes in the south Orange County city in return for constructing 688 acres of Great Park.

But the agreement is a big departure from what officials promised county voters in 2002 would be America's next great municipal park, a bucolic landscape that would cover 1,300 acres and include forests, a lake, museums and a 60-foot-deep canyon.

In its place, county residents will get a more active space, with a sports complex twice the size of Disneyland, a wildlife corridor and an 18-hole golf course.

With the approval, FivePoint Communities now has the right to build nearly 10,000 homes around the park land, the former site of the El Toro Marine Corps base. It will be one of the region's largest housing developments since the recession.

Final approval for the compromise came after a tense meeting, lasting nearly 10 hours, when it appeared that the eventual 3-2 vote could fracture over last-minute negotiations — including whether the city or the developer would control park operations.

To get the deal done, the developer finally agreed to give the city $10 million over time to maintain the park, starting in 2016, and an equal amount to improve the site's main entrance.

"I will defend to the death Irvine's ability to run its parks," Mayor Pro Tem Jeff Lalloway vowed before the final decision.

Earlier, Mayor Steven Choi tried to draw the council together, pleading, "We are in the middle of a historic moment." He, Christine Shea and Lalloway later voted in favor of the developer's vision, with council members Beth Krom and Larry Agran dissenting.

To some, the decision stood as a broken promise. The new park, several residents said, lacked the museums and cultural spaces that were part of the original plan. Others said the new look seemed too "theme park-like."

"They really are developing something that isn't creating a great public park in any way," Ken Smith, the New York landscape architect who spent years designing the space, said earlier this month. "It's just sort of cheap and fast and takes up a lot of space."

But years of spending and setbacks left city officials with few options.

In 2005, the military sold the land in an online auction to Lennar Corp., which struck a deal with Irvine to transfer about 1,300 acres to the city in return for being able to build thousands of homes. The company also paid Irvine $200 million.

City officials spent much of the money, but completed only about 230 acres of the park. Much of the land remains fenced off, dotted with old military barracks and criss-crossed by aging runways.

The real estate market crash slowed the arrival of the homes, and then Gov. Jerry Brown's decision to eliminate local redevelopment agencies — the financial engine generating tax funds to continue construction of the park — dealt a crushing blow to Irvine's plans.

Meanwhile, FivePoint, a Lennar spinoff, moved forward with plans to build homes around Great Park's perimeter, and had a seller's interest in making sure the space could be constructed.

"When you have conviction about something, you have to be patient that it will happen," Emile Haddad, the company's president and chief executive, said before the council meeting. "I believe this will happen."

anh.do@latimes.com