By LARRY LEBOWITZ AND MICHAEL VASQUEZ
Miami city and county leaders have forged a multibillion-dollar public-works bonanza that could alter the face of the downtown core -- affecting everything from a baseball stadium to a port tunnel to museums.

The plan, coming together with rare speed in the world of governmental red tape, envisions a holiday bounty of projects aimed at garnering support from constituencies ranging from sports fans to arts patrons.

Announced late Wednesday by Miami Mayor Manny Diaz, the deal would cover everything from a $914 million tunnel leading to the Port of Miami to finally transforming fallow Bicentennial Park into a waterfront jewel with new art and science museums.

By also shoring up the shaky finances at the fledgling Carnival Center for the Performing Arts, the plan's framework would free up additional tax monies that could be used to build a $525 million retractable-roof ballpark for the Florida Marlins.

''This is a great opportunity for all of us -- all of us -- to create an incredible legacy for the urban core,'' Diaz said following a long day of negotiating the multi-party pact -- and then selling it to individual commissioners.

While Diaz and others in the city embraced the so-called ''global'' agreement with the county, many questions remain.

One is whether a deal this complex can actually come to fruition. With so many parts forming the larger whole, it's possible that criticism of one piece of the blueprint could derail others.

Secondly, the intricate financing has been crafted in a way to sidestep a potential voter referendum -- which could embolden critics.

COMMISSIONS TO VOTE

Selling it is key, and the first test comes Thursday when Miami commissioners decide whether to move the multilayered plan forward.

County commissioners would then begin their review of key pieces of the ballpark financing and redevelopment plans Dec. 18.

The framework -- hashed out over several weeks of behind-the-scenes talks with city and county managers -- centers on expanding the Omni Community Redevelopment Agency to include Bicentennial Park and Watson Island.

CRAs are federally mandated special taxing districts that generate extra cash for areas targeted for revitalization. By aiming to expand the key Omni district, Miami leaders envision new infusions of money that would be doled out for multiple big-ticket projects.

The biggest beneficiaries of this new Omni CRA would be the Carnival Center for the Performing Arts and a proposed new ballpark for the Marlins at the soon-to-be-demolished Orange Bowl.

Diaz said the county would essentially receive up to $400 million in CRA revenue over the next 30 years to cover debt service on the arts center.

This will free up somewhere between $160 million and $200 million in tourist taxes from the PAC -- that the county and city could then use for the ballpark in Little Havana.

PARKING GARAGE

Less certain: whether the will, and the money, exist to build a 6,000-space parking garage and one of Diaz's personal projects -- a 25,000-seat soccer stadium also proposed for the 40-acre Orange Bowl site.

By expanding the CRA boundaries over the MacArthur Causeway to Watson Island, the city believes it can also use $50 million in CRA money to pay its share of the $914 million Port of Miami Tunnel over the next 35 years.

Florida transportation officials had vowed to move their $457 million share of the tunnel deal to other parts of the state if the city didn't put up its $50 million piece by Monday.

''I can finally see the light at the end of the tunnel, no pun intended,'' said City Commissioner Joe Sanchez, who represents the Orange Bowl area.

Miami property owners would also benefit from the expanded Omni CRA, city leaders say.

Diaz said the city would pay off its outstanding debt on the troubled Jungle Island construction loans from the expanded CRA instead of general revenues.

By expanding the boundaries into Bicentennial Park, the city would also use $68 million in new CRA revenue for the development of Museum Park -- including a planned underground parking garage. The CRA money would not be used to build the museums.

OVERTOWN IMPACT

Another question mark: whether city officials will be legally permitted to spin another $2 million a year out of the CRA to pay for ongoing capital improvements inside the park.

A second, more hard-pressed, special tax district would also benefit under the city-county pact.

The Southeast Overtown/Park West CRA, which generates considerably less revenue than the Omni, would be extended to year 2030 and its boundaries expanded to 20th Street on the north and Northwest Seventh Avenue on the west.

The city would spend up to $80 million for affordable housing, infrastructure, parks and job programs in the economically depressed Overtown neighborhood, and it would set aside $35 million for the city's struggling streetcar plan.

Diaz said Miami planned to adopt a pay-as-you-go approach when spending the CRA money on these big-ticket items over the next 30 years, rather than floating bonds to bankroll the projects.

The unstated reason: The projects wouldn't have to face voter approval.

In previous years, the city had contemplated issuing CRA bonds that could net perhaps hundreds of millions of dollars up front, to be used on large public-works projects.

But the Florida Supreme Court ruled in September that any bond issue local governments do with CRA money needs voter approval. Miami responded by abandoning its bond-issue plans.

This plan would sidestep those concerns.

DETAILS

As in every public project, the key is in the details, and literally hundreds of them still need to be hashed out.

First: Does Diaz have the three commission votes to pass the plan when the body meets this morning?

''God willing, [Thursday] we will approve possibly the most exciting -- largest, certainly -- package of projects in city history,'' Diaz said late Wednesday.

Commissioner Sanchez said of the ''global'' agreement: ``So far, it looks good. . . . It's a win-win situation for everybody.''

Herald staff writers Charles Rabin, Andres Viglucci and Matthew I. Pinzur contributed to this report.