The futuristic plan for Miami International Airport envisions newly arrived visitors checking in at a four-star hotel to relax at a pool, corporate executives hopping onto a people mover to meet at a business center minutes away, and locals crossing the street from the terminal to pick up Fido at the pet spa.

And the airport wouldn’t pay a cent to build any of it.

Instead, a private developer, Odebrecht USA, would finance the $512 million project. In return, Odebrecht would run the new facilities for half a century, paying rent and a percentage of revenues to the county.

This is Airport City, a massive project — in the works for nearly five years — intended to create new funding sources for the airport by turning MIA into a travel destination itself.

On Wednesday, Miami-Dade Aviation Director José Abreu will announce at the annual “state of the ports” speech, delivered with PortMiami Director Bill Johnson, that, three years after the county selected Odebrecht’s bid for the project, Airport City will come before county commissioners for approval next month.

“This can be the future,” Abreu said in an interview, calling Airport City “essential for us to be able to move forward.”

The reason: The more money the county-owned airport makes from non-aviation sources such as concessions, the lower the landing fees and other charges have to be paid by the airlines that bear the financial burden of operating MIA. During Odebrecht’s 40-year agreement with the county, with an option to renew for 10 more years, the airport could receive nearly $580 million in operating revenues.

“The more business we get, the more the airport gets,” said Gilberto Neves, president and CEO of Odebrecht. The company approached the county with the Airport City idea more than four years ago. Miami-Dade later put the project out for bids, and Odebrecht won.

Airport City would represent a capstone of sorts for MIA, which has spent about $6.3 billion and more than a decade — partly because of delays, cost overruns and, in some cases, corruption — expanding. The airport’s chief contractor: Odebrecht, which, as part of a joint venture with Parsons, upgraded the North Terminal, built a new South Terminal and put up the rails for the MIA Mover train that connects the airport Metrorail station to the terminal.

For Abreu, who was hired in 2005 to take control of the troubled capital-improvements program, launching an airport city — like the ones that exist in places such as Beijing, Frankfurt and Dallas/Fort Worth — is part of the legacy he hopes to leave when he retires at the end of March.

“The great thing about it is, it doesn’t hit our books” to develop the project, Abreu said. “There’s no downside.”

As part of the project, Odebrecht , which is working on a $4 billion mixed-use Rio de Janeiro port redevelopment project known as “Porto Maravilha,” would make the investment — and take on the risk — to develop, in phases, 33 acres east of the airport’s terminals and parking garages.

The county would retain ownership of the land, and the assets would revert to Miami-Dade at the end of Odebrecht’s agreement.

The project is divided into three parcels:

• A $359 million business center, with corporate offices, meeting space, a hotel and a new station for the MIA Mover train;