The final pieces of Mayor Mitch Landrieu’s landmark plan to create what could be the longest continuous stretch of public riverfront park in any U.S. city are coming together, officials said Friday.

Surrounded by officials and developers, Landrieu celebrated what he described as "the next step in opening up the river:" a 3.2-mile-long Tricentennial Park consisting of a variety of riverfront projects.

The plan, which will see park space stretch from Spanish Plaza at the foot of Canal Street downriver almost to the Industrial Canal, was all but finalized Thursday when various agencies approved a swap giving the city control of the Esplanade Avenue and Gov. Nicholls Street wharves — in the middle of the linear park — in exchange for turning the city-owned Public Belt Railroad over to the Port of New Orleans.

The city expects to spend $15 million to convert the two wharves into the final major piece of the park. 

"Despite their proximity, many historic neighborhoods and the public have been cut off from the river in other areas by floodwalls, railroads and industrial wharves," Landrieu said. "Since we were founded 300 years ago, the Mississippi River has been our most cherished resource."

As a whole, the various projects "will completely turbocharge, redefine and open up the river in a way that's never been done, and people can just imagine how incredibly future mayors, future City Councils and the neighborhood organizations will utilize that space to make an already wonderful riverfront better than it is," Landrieu said.

While the plan, for now, calls for mostly open park space along the riverfront, Landrieu isn’t counting out the chance turn the riverfront into a revenue generator in the future. A proposal is in place to create an economic development district that would cover the area, allowing the city to gain additional revenue from any attractions that may be built there.

The key elements of the plan have all been announced, and some are already underway.

The catalyst for Friday's announcement was the approval Thursday of the deal to swap the Public Belt Railroad to the Port of New Orleans in exchange for the two commercial wharves, which will allow the city to develop those wharves into public space. 

Public meetings will be held to determine exactly how the wharves will be used after the swap is formally approved by the City Council later this year, Deputy Mayor Ryan Berni said.

They will link Crescent Park, a 1.2-mile stretch along the river in the Marigny and Bywater neighborhoods that was completed in 2015, with the Moonwalk — the walkway along part of the French Quarter riverfront that was built in the 1970s during the mayoral term of Landrieu's father, Moon Landrieu — and, farther upriver, Woldenberg Riverfront Park, which the Audubon Nature Institute created in the early 1990s on the site of former working wharves and warehouses.

The Moonwalk — where Friday's news conference was held — is now undergoing a $3 million renovation paid for by the French Market Corp., and Audubon is spending $7 million to upgrade Woldenberg Park.

Other projects cited by the Mayor's Office as part of the overall riverfront redevelopment are a new $37 million ferry terminal at the foot of Canal Street, a $7.3 million pedestrian bridge to the terminal over the Public Belt Railroad tracks, the $400 million redevelopment of the World Trade Center into a Four Seasons hotel and condos, and a $7.5 million refurbishment of Spanish Plaza.

Beyond that, there's Crescent Park, which was completed in 2015 at a cost of $31.2 million.

On Friday, Audubon Nature Institute CEO Ron Forman described the work Moon Landrieu — who was at the news conference —  did to open up the riverfront in the 1970s, recalling the former mayor selling the idea of building the Moonwalk by bringing people up a series of steps to a deck so they could see over the floodwall by Jackson Square and get a view of the river.

"This is a historical moment," Forman said of the current series of projects —  "to take three miles of riverfront property in the city of New Orleans and bring the river back, our most important natural resource."

The series of projects will be completed over the next several years, with many not wrapping up until after Landrieu leaves office in May.

The plan also includes elements that suggest the possibility of more than just park space being developed.

According to the newly signed agreement between the Public Belt Railroad and the port, the port will work toward the creation of an “economic development district” that would include the riverfront from Spanish Plaza to Bywater, but exclude any port facility within that area, such as the cruise ship terminal at the downriver end of Bywater.

Such a district could generate sales tax revenue the city could then use for public safety or some other purpose, Berni said, though he stressed that the idea has yet to be fleshed out.

When asked what would generate revenue in the park, he suggested concessions and similar sales.

“It’s conceptual at this point,” Berni said.

Staff writer Jessica Williams contributed to this report.

Follow Jeff Adelson on Twitter, @jadelson.​