Minnesota United FC would need less than 10 acres to build a stadium in St. Paul for Major League Soccer, but city emails in June show team owner Bill McGuire saying an adjacent 25 acres “now is essential.”

“Concept would involve the stadium, office, retail, housing, hospitality, etc.,” wrote McGuire, who also inquired about the possibility of city or state government offices moving into the proposed spaces.

Starting in 2013, McGuire emailed St. Paul’s then-planning and economic development director about a “broad plan” for development near Interstate 94 and Snelling Avenue in the Hamline-Midway neighborhood. The plan included 10 acres owned by the Metropolitan Council and its vacant Metro Transit “bus barn” and 25 acres owned by commercial developer RK Midway.

United is exploring options to build an 18,000-plus-seat stadium in St. Paul or Minneapolis as home to an MLS expansion team by 2018. Plans in Minneapolis to help with property tax and sales tax exemptions on the privately financed stadium fizzled in the spring, and St. Paul moved to the forefront in July.

McGuire’s partners include the Pohlad family, which owns the Minnesota Twins and United Properties, a commercial development company that is believed to be the proposed developer for the St. Paul site.

McGuire, whose direct role in the proposed development is unclear, wrote in an email June 1 that he requested documents and pricing expectations from RK Midway, adding that a non-disclosure agreement had been executed.

Mayor Chris Coleman’s spokeswoman Tonya Tennessen said Monday that the stadium “could be a catalyst that would allow us to realize our vision for the site.” Tennessen said the city’s plans to optimize the site could include city money for infrastructure — sewers and the street grid — and green spaces.

However, Neil deMause, co-author of “Field of Schemes: How the Great Stadium Swindle Turns Public Money into Private Profit,” said the belief that stadiums generate further private development is false.

“At this point, the evidence is unequivocal that stadiums in particular are really lousy catalysts for development,” said deMause, who has studied dozens of stadium deals since 1995. “It doesn’t necessarily hurt development, but they’re not going to get you development that you wouldn’t get otherwise.”

A stadium would be host to about 20 MLS matches each season, with at least five dates for championship-level high school games and five dates for youth athletic association games, according to a legislation draft included in the city emails released last week. The stadium also could include other community events.

“That’s still well over 300 days a year that it’s a big dark hole,” deMause said.

CHS Field, the home of the independent league St. Paul Saints, provides another story. During a July 16 meeting at the new Lowertown ballpark, Saints executive vice president and general manager Derek Sharrer told McGuire that the city-owned facility had held 113 events in its first 137 days. That total includes all levels of baseball games as well as community events, but didn’t include the 26 Saints home games in that timeframe.

With Saints games included, the site averages more than one event per day.

“We’ll know more about what these numbers mean down the road, but what we know now is that this public-private partnership is over-delivering on its promise,” according to a copy of Sharrer’s speech shared with the Pioneer Press.

St. Paul Saints co-owner Mike Veeck said Wednesday that halfway through the season, his baseball team had sold more than 350,000 tickets as of Tuesday night, exceeding projections for the entire season.

“I’m very welcoming of the MLS, and I hope it’s successful,” said Veeck, pointing to how Saints games have drawn visitors to St. Paul’s event-driven downtown night life. “I think more is better, always.”

DeMause, a Brooklyn-based journalist, sees a comparison between St. Paul and development around Red Bulls Arena, the Harrison, N.J., home of MLS’ New York Red Bulls.

What St. Paul and Harrison have in common is proximity to commuter rail. Harrison has a system that feeds into Manhattan; St. Paul has the Green Line that connects its downtown to Minneapolis’.

Development in New Jersey is “happening less by the soccer stadium,” deMause said. “Maybe the soccer stadium put Harrison on the map a little bit but, really, all you needed to do was put up a sign saying ‘renovated (rail) station’ and people were going to come to your door to buy condos.”

In 1997, Harrison designated 250 acres for redevelopment, and Red Bulls Arena was opened in 2010. Other development has included improved infrastructure with projects for parking, commercial, residential and hotels, Harrison city documents show.

St. Paul’s plan for the southeast corner of Snelling and University avenues has been three years in the making, said Matt Kramer, President of the St. Paul Area Chamber of Commerce.

“In the last 24 months we’ve begun driving this and saying, ‘Hey, the city plan is coming to fruition, and this is a pretty freaking cool site,’ ” Kramer said.

The “bus barn” location has been vacant since 2002 but was used as a staging area for construction of the Central Corridor light-rail line until 2014.

The Metropolitan Council said the Twins’ Target Field has 10 percent of its fans arriving for games via the Blue Line that connects downtown Minneapolis to the Mall of America in Bloomington.

Steve Cramer, president and chief executive of the Minneapolis Downtown Council, said the combination of Target Field and Target Field Station “has been an accelerator” for development in its North Loop neighborhood. Cramer estimated the amount of office and residential development to be more than $100 million, with top projects being the renovation of Ford Center and the current construction of the Be The Match building across the street from the ballpark.

“It’s also true that those projects were done in an area of Minneapolis that was experiencing positive development momentum,” Cramer said. “It was a perfect storm of circumstances.”

However, when the Metrodome opened on the east side of downtown in 1982, it was built in a “sea of surface parking lots,” said Kramer, who has been involved in Minneapolis community development since 1979.

“It was put in a part of downtown that was not subject to any other positive development momentum,” he said. “And (there was a belief) that on its own it would generate that momentum. I think that just proved to be an inaccurate assumption.”

Kramer said the St. Paul development’s goal would be to keep a few city blocks together for the stadium while carving up the rest of the 35 acres with a street grid for multiple uses. He acknowledged that he views economic impact from a stadium construction both “positively and skeptically.”

“I will be the first to argue that the economic development argument around stadiums is spurious at best,” Kramer said. “They are job creators when they are under construction, and those construction jobs go elsewhere. They are entertainment creators when you create and design that right mix.”

Kramer said that proper ingredients include not only bars and restaurants often associated with stadiums but also housing and office spaces.

“You want it to be an economic destination, not just for people that are going for the entertainment value, but as a hub as an otherwise vibrant neighborhood,” Kramer said.

Sports economist Rob Fort said teams and cities are wise to include broader economic development in their stadium proposals. Politicians at the State Capitol cited “stadium fatigue” as a reason in April for their reluctance to provide tax help to build a stadium in Minneapolis.

“If folks don’t go for the stadium part of it, they have a hard time rejecting the other development aspects,” Fort was quoted in “Field of Schemes.” “And I think politicians know that as well as team owners.”

Fred Melo contributed to this report. Follow Andy Greder at twitter.com/andygreder.