The Florida Rock site awaits an ambitious mixed-use development. But first, kickball. (Katherine Frey / The Washington Post)

Plans for a sprawling temporary entertainment complex next to Nationals Park featuring kickball fields, bocce courts and alcoholic beverages have run into opposition from neighbors and police. And the prominent name of one of the partners involved has raised some eyebrows: Vincent Carlos Gray, son of Mayor Vincent Condol Gray.

“Riverfront at the Ballpark” is planned as a temporary use for the six-acre former Florida Rock Industries site immediately south of Nationals Park until plans for a permanent mixed-use development come to fruition.

According to documents submitted to the Alcoholic Beverage Control Board, which is currently deciding whether to grant a liquor license for the site, Dos Ventures LLC is proposing to offer lawn games, live performances, “pop-up” food vendors and “festival like” programming such as batting cages. Musical acts and adult sports leagues could use the site on non-game days.

Carlos Gray, 36, acknowledged in an interview that he is a partner in Dos Ventures but declined to share further details about the plans or his involvement in the project. The lead partner is Ki Jun Sung, who owns the Capitale club downtown; Gray is listed as a “DCRA/planning consultant” on a form filed with the liquor board. Gray campaigned for his father in 2010 but has generally kept a low profile since, politically speaking. “I’m just not a spotlight type of person,” he said.

The Department of Consumer and Regulatory Affairs issued a building permit on July 24 allowing Dos Ventures to lay crushed gravel and grass on the site, making way for temporary bars, tents and stages, as well as a 30-space parking lot. A letter from the department’s chief building inspector said the site could conceivably accommodate as many as 12,200 occupants. It is unclear just how many revelers Dos Ventures expects to host.

“We’re catering to some of the Nats fans,” Gray said. “We’re creating a social environment.”

Ed Kaminski, an advisory neighborhood commissioner who represents the area north of the ballpark and is part of a group opposing the liquor license, said the younger Gray’s participation was “incidental,” as far as he is concerned. “It’s the size and the magnitude of this project,” he said.

The project has generated unusual objections from Police Chief Cathy L. Lanier, who wrote in a June 14 letter to the Alcoholic Beverage Control Board that the “establishment could conceivably accommodate far more patrons than any other [liquor-licensed] facility in the District of Columbia, which would prove to be extremely labor intensive from a law enforcement perspective.” Lanier also raised concerns about the the traffic and pedestrian safety implications and the lack of plumbing.

Riverfront at the Ballpark does have some neighborhood support. David Garber, the advisory neighborhood commissioner who represents the immediate area, sent a letter to the liquor board last week supporting the project, saying it would “promot[e] a healthy, fun and cohesive community through a variety of interactive sports and outdoor food, drink and entertainment programs.”

“[A]ctivating this space with a temporary use such as Dos Ventures is proposing is a concept that many in the neighborhood support and would love to see come to fruition soon,” he continued.

The project was the subject of a five-hour hearing before the Alcoholic Beverage Control Board Wednesday. The board will issue its decision on the liquor license within 60 days, a spokesman said Friday.