Updated

Those whispers that circulated for months about a possible arena plan that might bring the NBA back to Seattle — and perhaps professional hockey, too — are now replaced by a concrete proposal with a staggering private investment.

The question now is whether the plans unveiled Thursday by wealthy San Francisco businessman and Seattle native Christopher Hansen will ever become a reality.

Hansen's proposal would help heal the scars from the SuperSonics' messy divorce with the city in 2008 that led them to a new home in Oklahoma City, leaving behind more than 40 years of history essentially over an unprofitable arena. But his proposal comes with the condition that no shovels will go into the ground until NBA and NHL franchises are locked in as tenants for the next three decades — not exactly an easy task.

From the fans' perspective, Hansen's proposal to the city and King County is a victory after nearly a year worth of behind-the-scenes work. The proposal features an eye-popping $290 million in private investment just for the building itself, not including the cost to Hansen's investment group for purchasing a new NBA club.

On the surface, there appears to be minimal risk to the local municipalities. Their contribution to the project is capped at $200 million and would not include new taxes, but instead would be paid off through taxes and rent collected on the tenants of a gleaming new building. It could spurn additional revitalization in an area that features Safeco Field and CenturyLink Field, but has its eyesores of vacant buildings and drab warehouses.

The public portion of the proposal would come in the form of bonds issued by the city and county to help cover construction costs and would be paid off over the life of the lease signed by the franchises. The arena would be publicly owned. City Councilman Tim Burgess said he and his colleagues would examine the plan "to make sure that our exposure and risk is zero."

"When people say there are no new taxes, that's literally true. But it's not correct to say public money is not involved," Burgess said. "We are being asked to sell bonds and finance part of the arena. That raises questions about our debt limit ... so there's lots of questions. The devil is in the details."

Approval of the proposal would eventually be needed at both the city and county level. But the months of work by lawyers, arena experts, Hansen's investors and city staff will be for naught unless a franchise is willing to call Seattle its new home.

"My understanding is there are pathways to obtaining a team and (Hansen) is obviously not going to be committing the time and effort he's been committing so far and the potential dollars unless he feels his prospects are good," Seattle mayor Mike McGinn said. "Again, that's his job, not our job. Our job is to make sure we're in a position to respond and provide an answer."

The most obvious target for landing that anchor tenant would be Sacramento, where the city faces a March 1 deadline imposed by the NBA for coming up with a financing plan for a new arena in California's capital city. The lynchpin in Sacramento's arena plan — a proposal to divert and privatize parking revenues to pay for roughly $200 million of the arena project — is tentatively scheduled for a full City Council vote on Feb. 28.

Public documents released by the city of Seattle show that Hansen is closely watching the situation in Sacramento. But if the Kings can get their new arena, then the question is who the next possible target becomes since the NBA has no plans for expansion. New Orleans is currently operated by the NBA, but commissioner David Stern seems determined to find a local owner who will keep the Hornets in Louisiana. Other franchises are struggling but none are serious candidates for relocation.

While getting the NBA is Hansen's focus, part of his charge is finding a partner to bring in an NHL franchise. City officials said Thursday that their financial estimates for how the public investment would be paid off are based on the assumption of having both NBA and NHL teams.

Seattle would be an attractive market for the NHL — commissioner Gary Bettman said as much last month at the All-Star Game — and could face competition for either a relocated or expansion franchise from places such as Quebec City and the push for a second Toronto area franchise.

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