Rendering of the Potomac National Stadium. (Courtesy of Wilson Sonsini Goodrich & Rosati)

The Washington Nationals’ minor league affiliate in Prince William County announced plans on Tuesday to build a stadium as part of a proposed $70 million public-private partnership that officials hope will serve as an anchor for a retail development and a transportation hub for Interstate 95 commuters.

The Class A Potomac Nationals, which signed on with the Washington Nationals when the major league franchise moved to the District in 2005, have long played at G. Richard Pfitzner Stadium, a Prince William County-owned facility behind the central county office building in Woodbridge. That field has been beset by maintenance problems in recent years and has served as a source of contention between Nationals officials and Potomac Nationals owner Art Silber.

The prospect of a $25 million, 6,000- to 7,000-seat stadium just off I-95, at Exit 156 in Prince William, is the closest officials have been to a new complex for the team, which has been looking for fresh environs since the mid-1990s.

But officials cautioned Tuesday that the plan has several partners and many moving parts, which will require funding and vetting before the stadium becomes a reality. And like many major development projects in the county, the stadium proposal is likely to face considerable scrutiny from the surrounding community.

“I actually had to see this to believe it,” said Jonathan Pick, 36, a Woodbridge resident who attended Tuesday’s news conference and said he goes to about 50 home games a year. He said the current stadium is “dilapidated” — with metal seats, no shade and just one concession stand. He has visited other stadiums around the Carolina League, in which Potomac competes, and said they are newer and nicer.

Pfitzner Stadium opened in 1984, making it the second-oldest stadium in the eight-team Carolina League. Pfitzner’s average attendance is third from the bottom, at about 3,000 fans per game.

The new stadium would be a part of Stonebridge at Potomac Town Center, a shopping and residential center that is being built by Roadside Development of the District and that is anchored by a Wegmans grocery .

The Commonwealth Transportation Board has authorized the Virginia Department of Transportation to invest about $15 million. That would pay for a new parking structure with about 1,000 spaces for fans and for commuter slugs catching rides on I-95. Roadside Development, which manages Stonebridge, would invest about $30 million in site and infrastructure work, and the P-Nats would pay for construction of the stadium.

Prince William Board of County Supervisors Chairman Corey A. Stewart (R-At Large), who said he shepherded the deal with state Transportation Secretary Sean T. Connaughton, said no local dollars are planned for the project, in direct funding or tax breaks. Connaughton, who preceded Stewart as chairman, said he worked to get the P-Nats a new stadium when he chaired the Prince William board.

Officials said that Tuesday’s announcement would not have happened without the support of VDOT’s “anchor money,” as Connaughton put it, that the state is providing.

Silber said finding $25 million for the stadium should not be a problem. “I’m going to write a check,” the P-Nats owner said of funding the complex.

Mark Scialabba, the director of the Nationals’ minor league operations, said having a minor league team close to home allows the team to grow its fan base and saves time and miles when players are sent for rehab stints. Last year, Scialabba wrote a letter to Major League Baseball saying that the P-Nat’s field needed to be upgraded, prompting Prince William officials to provide funding for upgrades to Pfitzner.

“We want to provide our players with the best field and clubhouse . . . so they can develop,” he said.

Roadside Development would also seek to put in 300 new residential units and an office building that would come along with the stadium plan, said Richard Lake, a founding partner.

He compared the plan, anchored by the large VDOT commuter garage, to downtown Bethesda, where restaurants and shopping “populate around parking garages.” The site will require plans dealing with the environmental impact to two streams on the 22-acre site, and public feedback over the coming weeks.

“We’re not interested in upsetting anybody,” Lake said in an interview.

A series of community meetings are planned for the fall, said Supervisor Frank J. Principi (D-Woodbridge), and the issue would probably have to go before the full board of supervisors for an up-or-down vote. If all goes well, officials said, the new ballpark and commuter lot could be open at the start of the 2014 season.

“We want to make this the social, athletic and entertainment center of this community,” Silber said.