MIAMI -- If the notion of building a Major League Soccer stadium on PortMiami land seemed fraught with practical complications and political pitfalls, try putting one on water.
David Beckham and his investors are examining whether filling a deep boat slip with rocks, forever altering the jagged edges of downtown Miami's shoreline, would work as a location for their planned stadium.
They're likely to find at least as many challenges as they did for their first-choice port site.
There are new costs to weigh, environmental and building permits from federal, state and local agencies to request -- and not one, but two municipal governments to persuade.
Beyond those logistical and political considerations is a broader question for elected leaders in Miami-Dade County and the city of Miami. Do they want to turn over the last remaining piece of public, open waterfront along Biscayne Boulevard to a private entity to build an imposing structure?
"You're basically giving away public land," said Laura Reynolds, the executive director of the Tropical Audubon Society, who has repeatedly fought attempts to fill the water basin over the years. She sent the county a letter Friday opposing it as a stadium site.
County Mayor Carlos Gimenez, who asked Beckham's group to take a serious look at the location, said he proposed the idea to create a hub of recreation and cultural attractions. Though he brought it up to the team just last week, county records show Gimenez asked staff to run scenarios to fill the slip in December 2012. Rumors about Beckham's interest in Miami began to intensify the following spring.
A filled basin would connect Museum Park to AmericanAirlines Arena along the water -- a promenade that would extend to the county-owned property known as Parcel B behind the arena. Parcel B had been promised as a place for public access to the bay, but has been used merely as a staging site for arena events.
Parcel B is key, said John Alschuler, the Beckham group's real-estate adviser, who said the 2.76-acre property offers enough room for a meaningful park.
"This is your chance to do Millennium Park in Chicago," he said.
Gimenez has given Miami Beckham United until May 19 to figure out if a stadium on the slip is feasible. Alschuler told The Miami Herald's editorial board last week that if the price tag is close to the $250 million the group estimated it would need to privately fund construction of a port stadium, then the investors would be on board. The group also intends to apply for a state subsidy.
Rent or some other sort of compensation for the public land would still be required, Gimenez said. There's talk behind the scenes of Beckham contributing to a fund for city park maintenance and improvements.
According to Beckham's analysis, port construction would cost $50 million more than at alternative locations at the time -- chief among them next to the Miami Marlins' ballpark in Little Havana. The group was willing to take on the additional expense in order to be on the water, with a highly marketable downtown view from the port's southwest corner.
Building on the water basin would likely entail fewer infrastructure costs, since it's smaller and surrounded by developed land. But filling even just three-quarters of the slip could cost about $17 million, according to an estimate the county's public works department made in December. (Earlier drafts of the estimate were higher.) Using dirt from the nearby port dredging product could save $1.5 million, though Gimenez has said using that material would be unlikely.
There would also be other costs. In 2011, Miami commissioners passed a resolution against any "actions or discussions" by the county to fill the city-owned Florida East Coast Railway slip. The city has invested close to $12 million to upgrade the basin's sea wall and install moorings for large vessels, according to Miami's capital improvements office.
"The above investments were made in recognition of the unique element the FEC slip brings to Miami's urban, waterfront environment," the legislation said.
The slip measures 1,200 feet by 315 feet at its widest point and has a maximum depth of 27 feet, according to the county. In all, the property has an area of about 9.91 acres, with 7.85 of those acres under water. It forms a nearly perfect rectangle because its shape is man-made: The areas north and south of it were filled to create land east of Biscayne Boulevard.
So important was the site, then part of a larger tract, that the city acquired it for $23 million in the 1970s after eminent domain proceedings in court. Miami promised a bayfront park; to pay for the purchase, it used funds from a bond issue, known as Parks for People, that voters approved in 1972. In the 1990s, the city sold the southern portion of the tract to the county for $36 million for arena construction.
Filling the basin might leave the city on the hook for more than $3 million in grants it received in recent years from the Florida Inland Navigation District for improvements. The grants were awarded on the condition that the basin remain public for 25 years.
"There might be a reimbursement situation," said Mark Crosley, the district's executive director. But he said he's open to a potential fill plan, especially if it allows more people to enjoy the waterfront.
"I think it's a little underutilized," he said of the slip. "Maybe if something happened on that shoreline, that would be a good thing."
Spencer Crowley, the Miami-Dade commissioner for the navigation district, works as an attorney for the Akerman law firm representing Beckham's group.
As the only deep-water basin in Miami-Dade and Broward counties outside PortMiami and Port Everglades, the slip has been used to dock mega-yachts and, in 2012, Volvo Ocean Race sailboats. Next month, the Eagle, a U.S. Coast Guard cutter, is scheduled to dock there.
The slip is part of the Biscayne Bay Aquatic Preserve, which the state created to protect the bay's biological and aesthetic value. The designation generally prohibits filling, though there are exemptions if the development is deemed to be in the public interest.
The preserve amounts to a park on the water that should remain untouched, said Reynolds, the environmental advocate.
A biological assessment conducted in January 2013 by divers in Miami-Dade's Division of Environmental Resource Management, or DERM, found "negligible" traces of sea grass; some algae; small coral; lobster and several species of fish, and submerged trash and debris.
A fill plan would require permits from DERM, the Florida Department of Environmental Protection or South Florida Water Management District, and the U.S. Army Corps of Engineers, whose processing times are notoriously difficult to predict. DERM estimates that all the permits could be obtained in 12 to 20 months, according to Deputy Mayor Jack Osterholt, who oversees the agency.
The city would have to apply for the permits -- and change the property's zoning to allow a stadium -- if it maintains ownership of the site. Miami could sell the land to the county, which appears unlikely, or convey it to Miami-Dade.
It's not only the slip site itself that would be in play.
To fit a 25,000-seat soccer stadium, the building would have to encroach on the city-owned Museum Park next door.