– Wielding golden shovels, Rochester officials broke ground Thursday on an $84 million expansion of the city’s Civic Center, the latest in a whirlwind week of construction and development news for the Mayo Clinic’s home city.

The Civic Center will grow up and out, nearly doubling in size by the time renovations finish in 2017, thanks to a state grant and a boost in the city lodging tax.

Just days ago, the city revealed plans to buy a historic downtown theater for $6 million. The purchase was billed as important to the city’s future, though what the city will do with the theater remains undetermined.

Also this week, MnDOT launched the first phase of an environmental review for a 100-mile commuter rail line connecting Rochester with the Twin Cities, a proposal pitched by a group of private investors. The line could cost upward of $4 billion.

The projects have taken shape as Rochester prepares to launch Destination Medical Center (DMC), an ambitious plan backed by $585 million in state funds to remake the city as an international center for health care and medical research. The plan’s broad outline is expected to get final approvals next month.

“I can’t think of a more exciting time for Rochester than right now,” said state Sen. Carla Nelson, speaking to VIPs after the groundbreaking.

Although the Civic Center expansion aligns with the goals of the DMC plan, it’s not directly tied to it, nor will it be paid for with DMC money. A $35 million state grant approved by the Legislature last year will cover nearly half the cost. A 3 percent bump in the city’s lodging tax from 4 to 7 percent will cover the rest, or about $49 million. The new tax rate took effect last year.

The renovations will add more second-floor space and give it a bigger footprint along the South Fork Zumbro River and the 11-acre Mayo Park at the center of downtown. The new, bigger Civic Center will be able to host two conventions of 1,000 people each simultaneously. Construction should be completed by 2017.

The larger center will keep Rochester in the running for conferences previously lost, the city says. In 2008, 68 conventions went elsewhere because Rochester’s facility was too small, taking 136,500 attendees and $74 million in spending with them.

Sen. Dave Senjem, R-Rochester, said he recalled going to the Civic Center while growing up in nearby Hayfield to see acts like Roy Rogers and professional wrestler Hard Boiled Haggerty.

Lining up for their publicity shot, VIPs took turns tossing shovelfuls of gravel on the spot where construction equipment will soon tear into the earth.

The project includes expansions of the adjoining Rochester Art Center and Rochester Civic Theater.

“We’re beyond excited to get this in the ground,” said Brad Jones, executive director and CEO of the Rochester Convention and Visitors Bureau.

His office predicts a string of benefits, with $372 million in local economic activity over 10 years, and another $120 million out of state, according to city projections. Those projections include some 700 jobs for the renovations, plus “hundreds” of full-time jobs once it’s completed.

Déjà vu?

While Rochester officials celebrated the end of eight years of planning and the start of construction at the Civic Center, a new and even more ambitious plan to build a high-speed rail link, or Zip Rail, between Rochester and the Twin Cities commuter rail line made early, tentative steps.

State transportation planners and Olmsted County have mulled the prospect for some time. But more recently, representatives of a group of Minnesota businesses and private investors have been meeting with state and local officials about the possibility that a rail line, which could cost upward of $4 billion, could be mounted entirely with private funds.

“If a private funder was allowed to be able to put that piece in place, it would truly benefit the DMC plan,” said Wendy Meadley, a consultant working for the investment group. They have formed an LLC: the North American High Speed Rail Group.

Meadley said group members aren’t ready to go public, but she described them as representing “blue-chip Minnesota businesses.” She said the group would reveal itself in April.

Gov. Mark Dayton has had an initial briefing on the private proposal, and Transportation Commissioner Charlie Zelle has had discussions about it.

In the meantime, MnDOT this week launched the first phase of an environmental review to gauge impacts of eight potential routes. The 100-mile line would connect downtown Rochester to downtown St. Paul, the Minneapolis-St. Paul International Airport or other locations, affording a one-way trip in about 30 minutes.

But any line would require land acquisition for new tracks, a daunting process for government agencies and municipalities.

“It’s going to cost our cities millions of dollars to rebuild our roads and utilities, all because Rochester wants this,” said Norma Monroe, a retiree who lives on a farm near Kenyon. “It’s not even going to stop in our communities.”

Many GOP legislators oppose any use of tax dollars for the project. Rep. Pat Garofalo, R-Farmington, said the private investors told him they would not oppose legislation barring any use of public money to build or operate the line.

Meadley said there’s no real precedent nationwide for private construction and operation of a rail line. While noting it would still be subject to environmental reviews and other government oversight, Meadley pitched private investment as a more efficient way to get the line built.

“Usually why big transportation projects take so long to get done is because you’re always waiting for that next chunk of money from the government,” Meadley said.