Active or passive? That was the essential question at two recent citizens’ meetings to discuss plans for the proposed 11th Street Bridge Park. Should it be used mostly for organized activities, or for strolling, viewing and musing?

The park would sit atop a new 2.84-acre platform across the Anacostia River, adjacent to the westernmost of the three new 11th Street bridges. The structure would be erected on piers that remain from one of the two bridges replaced by the trio of new crossings.

About 50 people gathered for each of the Dec. 7 parleys, one in the morning at a church on the Anacostia side of the river and the other in the afternoon in a city government office building near the Navy Yard.

Harriet Tregoning, director of D.C.’s Office of Planning, introduced the second session. “Ten years from now, you’ll be able to say . . . ‘See that part, that was my idea,’ ” she said.

The idea for the park draws from such projects as New York’s High Line and Paris’s Viaduc des Arts, elevated railway lines that were remade as garden promenades. Neither of those crosses a river, but there are plans for garden bridges that span rivers in Providence, R.I., and London.

An artist’s rendering shows what the 11th Street Bridge Park could look like. (D.C. Office ofPlanning)

The latter is projected to open in 2018, about the same time the 11th Street Bridge Park would debut — if $25 million can be raised for construction and an additional $10 million for an endowment to fund programming.

There have been “a little more than 160 community meetings” about the proposal, said Scott Kratz, one of the planning sessions’ organizers. Kratz has been working on the bridge park as a volunteer for two years and will become its paid project manager next month. His imminent employer is Building Bridges Across the River at THE ARC, which is overseeing the park’s development but is better known for its Southeast arts center.

“We’ve heard the same concepts again and again from people on both sides of the river,” Kratz said of the seven elements presented at the meeting. “This was the first time that we asked the community to rank them.”

Most enthusiastically supported at both forums were a performance space, public art, a playground, and a launch for kayaks and canoes. Less support was voiced for a restaurant, an environmental education center and “urban agriculture,” which might entail a vegetable garden or a fruit orchard.

“We heard that loud and clear,” Kratz said of the meeting participants’ interest in openness and adaptability. “We need to make sure that we include quiet spaces for contemplation.”

Several locations along the Anacostia, notably Kingman Island, have been suggested as sites for an environmental education center. Kratz said he checked with other groups to ensure such a facility “is not duplicative. The Anacostia River does not need 10 environmental education centers within two miles of each other.”

The bridge park would not serve primarily as a way to cross the river, Kratz said. “We’re building a new deck, and since that deck doesn’t have to be flat anymore, the designers are going to have a real field day with this.”

If a streetcar line is built on the adjoining span, he noted, there might be one or more mid-river stops with pedestrian connections to the bridge park.

Planning has been funded by about $540,00 in cash and in-kind contributions from real-estate development firms, philanthropists and civic groups, Kratz said. About 20 percent of the money came from the D.C. government, which will remain a partner because it controls the property.

“The District owns the bridge, and it will continue to be owned by the District going forward,” Kratz said. “But it would be managed by a private entity like a Building Bridges Across the River at THE ARC.”

Responsibility for maintaining the finished bridge park hasn’t been determined, he said.

At a date Kratz described as “March-ish,” a nationwide design competition will be announced for the park. A review committee will winnow the applicants to three, and a jury will pick the winner. Members of the committee and jury have not been chosen.