Bloomington leaders are nearing final approval of an elaborate plan to help build one of the nation's largest water parks beside the Mall of America.

The deal hinges on the city's option to hike sales taxes at the Mall of America to pay debt on the $260 million facility, if visitors who pay to raft down 10-foot-wide slides and lounge in cabanas don't generate enough revenue. The City Council voted unanimously Tuesday to authorize imposing the taxes — 11 years after the Legislature granted them that power — under specific circumstances that will be agreed to next month.

A series of votes scheduled for Dec. 17 will finalize an unusual financing plan with little precedent in Minnesota.

Under the deal, a Louisiana-based nonprofit organization will borrow money from an Arizona public development authority to build the park. Then a Mall of America affiliate will manage it. The debt will be guaranteed by a city pledge to raise sales taxes at the mall if water-park revenue falls short. Bloomington will pay more than $55 million for a parking ramp and skyway, and the water park will pay rent to Mall of America owners for using their land.

No one testified at a public hearing about the taxes at Bloomington City Hall on Tuesday night. Voters last week elected a supporter of the water-park plan, City Council Member Tim Busse, to be the city's next mayor — succeeding Gene Winstead, another champion of the project.

Before the vote, Mall of America representatives briefed city leaders on what visitors will find inside the glass-covered, multilevel 325,000-square-foot facility. Updated renderings show a tropical oasis replete with palm trees, thatch-roofed structures, lounge chairs, wave pools and a mock steamer ship.

"This isn't a traditional water park where you're seeing the North Woods type landscape and feel," said Nate Klutz, the mall's vice president of construction. "We're trying to create our own unique branding, our own unique experience."

A centerpiece is a slide complex reaching 70 feet high, where groups on rafts can barrel down wide, translucent multicolored fiberglass tubes.

Chris Grap, lead storyteller and experience designer for the Mall of America, said they worked carefully to make the most of limited space.

"We kind of like to say it's all killer and no filler," Grap told city leaders. "We've made sure there aren't any redundant experiences within the park."

Grap said they have broken the park up into five "outposts" with their own music, plants and "rock work."

"We want this project to last well beyond the impression of a first visit," Grap said. "There's not one 'wow' moment. There's 20 'wow' moments. We want to build a sense of discovery. We want people to be able to walk in the space and recognize that this isn't a water park. Really we've designed it as a theme park with water-based attractions."

A Bloomington official said last month that the working title is "Mystery Cove," though Mall spokeswoman Sarah Grap said a name has not been chosen.

Taxes, feasibility

But can it turn enough profit? That's the subject of a feasibility study by Hotel and Leisure Advisors that the city expects to receive before Thanksgiving. That study will be put into the preliminary operating statement for the bonds on the project.

"So it's not [Mall of America ownership] projections, it's not the city's projections, it's an independent third party whose livelihood is to project the performance of water parks," said Schane Rudlang, administrator of Bloomington's Port Authority.

The sales taxes approved Tuesday night would only apply at the Mall of America and the block north of the shopping center. The city is authorized to charge a hotel tax, admission and recreation tax and general sales tax of up to 1%, as well as a food and beverage tax up to 3%.

The city will vote on a plan next month to impose the taxes — or portions of them — automatically depending on certain circumstances.

"It's designed so that there would be no subsequent action before the [City Council]," said city attorney Melissa Manderscheid. "These will happen as a result of certain things occurring outside of the City Council."

The tax plan stems from a deal brokered at the Capitol 11 years ago. Then-Gov. Tim Pawlenty supported using sales taxes to fund the mall's expansion after vetoing an earlier attempt to redirect money from a regional tax sharing pool known as Fiscal Disparities.

In 2013, the Legislature and then-Gov. Mark Dayton also exempted the mall from the tax-sharing pool. That allowed Bloomington to subsidize infrastructure related to the mall's expansion — such as the parking ramp and skyway for the water park — with money that would have helped reduce property taxes elsewhere in the metro.

Eric Roper • 612-673-1732 Twitter: @StribRoper