Created in the 1930s in San Francisco Bay, Treasure Island is said to have earned its name from the gold some imagined was hidden in dredged materials that form its foundation, as well as the exotic valuables displayed there for the 1939 Golden Gate International Exposition.
Developers have continued to view the 400-acre former Navy base as a precious commodity, and a proposal to turn it into a bustling residential and commercial enclave recently cleared a major hurdle when it was narrowly approved by the city Planning Commission.
The plan includes nearly 8,000 new homes, 140,000 square feet of retail space and 300 acres of public open space _ a drastic change to a neighborhood that now has fewer than 2,000 full-time residents and just two restaurants.
Supporters say the 15-year project would finally tap the island's potential and provide a rare expansion opportunity for a city surrounded by water on three sides.
Opponents counter that the population boom would put a significant strain on the environment and create a traffic nightmare on the Bay Bridge, one of the region's primary transit arteries and the only way to reach the island by car.
Some current residents and commercial tenants are eager for change, describing the island as a gem that remains far too hidden.
Mark Connors moved to the island about seven years ago for its affordable rent and abundant fresh air, but it was the prospect of redevelopment that kept him and his husband from leaving.
"The island itself needs some work, new infrastructure," said Connors, 51, who acknowledged some concerns about increased bridge traffic. "This is going to be a great city planning experiment, and I think we're all going to learn a lot as it comes together."
Alexis Valerio, director of business development for The Winery SF, one of the island's best-known businesses, said the project would bring new life to the island.
The winery, which occupies a 20,000-square-foot former clipper ship hangar, would likely have to find a new home if the plan is adopted, but Valerio said she still supports the "big picture" benefits for the island.
If the April 21 city Planning Commission meeting was any indication, members of the Board of Supervisors could be in for a long, intense debate when they take up the issue in June.
The commission spent six hours scrutinizing the plan, eventually splitting down political lines, with four mayoral appointees voting for the plan and three members appointed by the board voting against it.
After the 1939 exposition, Treasure Island was supposed to become San Francisco's first airport. But the Navy saw it as an ideal site for a base during World War II and offered the city a trade for a larger parcel of land in South San Francisco.
Since the base closed in 1997, the island has seen the arrival of several wineries, an occasional Gaelic football match and production crews for "Indiana Jones and the Last Crusade," "MythBusters" and other films and TV shows. Plans to build a theme park, casino and luxury golf courses all have failed to gain traction.
The latest proposal has the endorsement of Mayor Edwin Lee, who was appointed in January after former Mayor Gavin Newsom was sworn in as lieutenant governor. Newsom was a vocal proponent of island redevelopment.
"The Treasure Island project will create a new, unique San Francisco neighborhood that has broken new ground with smart design elements that respond to the challenges of developing on an island," Lee said.
Those challenges include making sure the manmade island can withstand earthquakes, tsunamis and rises in sea level.
The development team, which includes Wilson Meany Sullivan, Lennar Urban and Kenwood Investments, has proposed some ambitious solutions, including crushing more than a million cubic yards of fill into the ground and elevating new building pads, streets and infrastructure several feet to protect against flooding.
Developers also point to environmentally sustainable features such as a system to recycle water, buildings and streets angled to maximize sun exposure and reduce wind, and various offerings to encourage the use of public transportation, including a new ferry terminal and subsidized transit service.
"At Treasure Island, you have a unique opportunity to address sustainability not as an afterthought but in the very formulation of the place," said Chris Meany of Wilson Meany Sullivan, one of the developers.
Critics say the question is not how green the island will be, but how the addition of 19,000 new residents will affect the larger San Francisco Bay area.
"What Treasure Island represents is a concept of sustainability that's specific to the island itself, but not the region," said Saul Bloom, executive director of Arc Ecology, a nonprofit environmental group.
Of particular concern is the potential addition of thousands of commuters to the already congested Bay Bridge.
"If you could choose one place in the entire Bay Area to completely mess up traffic, that would be it," said Tom Radulovich, executive director of Livable City, a group that promotes transportation reform in San Francisco.
Livable City and other groups have criticized the amount of parking contained in the plan _ one spot per residential unit. That does little to encourage people to embrace alternative means of transportation, Radulovich said.
Meany argues the population of the San Francisco Bay Area is growing whether or not his project becomes reality. Treasure Island's close proximity to downtown San Francisco _ five to 10 minutes by car or ferry _ makes it an ideal location to absorb some of that growth, he said.
"The issue here is we have people, they need to be accommodated, and we know that if we continue to allow our region to sprawl, the negative impacts will be amplified," Meany said.
Environmental concerns will likely be a major focus when the Board of Supervisors takes up the plan.
Another contentious issue will be a recent change in the project's quota for affordable housing. Currently, 25 percent of the 8,000 planned units would have to be set aside for low-income residents, down from the original requirement of 30 percent.
The shift is a result of Gov. Jerry Brown's proposal to eliminate redevelopment agencies to save the state money. Infrastructure improvements on the island would cost an estimated $1.5 billion, and San Francisco was counting on redevelopment funds to cover one-third of those costs. The remaining two-thirds would come from developers and tax revenues from the future residents.
With redevelopment money temporarily off the table, the city plans to pay for the project using infrastructure financing districts, in which property tax revenues are diverted to fund improvements to public property. However, that mechanism was not expected to generate enough money to pay for 30 percent affordable housing.
Lee said he is committed to restoring the original affordable housing quota and already has begun lobbying the state for additional funding.