A pair of architectural firms from the Netherlands and Philadelphia are the winners of a frenzied competition to design a $40 million park that would traverse the Anacostia River and could help unite the communities on its banks.

The 11th Street Bridge Park project, an effort backed by the D.C. government and private donors, aims to erect a public gathering space atop piers that held up the old 11th Street Bridge before it was replaced.

More than 4o teams comprising 82 firms expressed interest in designing the project, and the field was narrowed to four finalists. Late last month, a panel of experts selected a proposal from the Office for Metropolitan Architecture (OMA), which has global headquarters in the Netherlands and U.S. offices in New York, along with Philadelphia-based Olin Studio.

The proposal, “Anacostia Crossing,” calls for a central plaza, an enclosed café, an environmental center and other elements that when combined form a sloping ‘X’ shape.

Its designers envision the park as a defining feature for a river typically characterized by the pollution it endures and a yawning gap in economic fortunes between residents on its two banks.

Jason Long, a partner at OMA’s New York offices, said the project — similar to New York’s High Line Park and other major municipal projects — offers the District a chance to take advantage of the abandoned bones of old transportation routes and use them to create parks, walkways and other civic spaces.

“At this moment, really all throughout the country, people are trying to grapple with what to do with post-industrial infrastructure spaces that are suddenly available for use by the public in ways that they weren’t before,” he said.

The project has four goals: create economic development, improve public health, connect communities on either side of the river and re-engage residents with the river itself.

To meet them the OMA/Olin proposed a bevy of features both along a platform above the water and on the banks on the eastern side of the river, among them boat launches, an amphitheater, an interactive art feature, a grove of hammocks and a series of nets that would allow people to dangle out over the river.

Olin partner Hallie Boyce said the design would encourage interaction between both sides of the river and become a destination for people from around the city. “We knew it had to be both connector and place,” she said.

Scott Kratz, director of the 11th Street Bridge Park, and a committee of volunteers held more than 200 public meetings in order to gather input for the project and solicited online feedback from the public before a jury of professionals made the selection. He said the public and the jury agreed that Anacostia Crossing best met the project’s four goals.

In many ways, however, the heavy lifting for Kratz and other backers of the project lies ahead, particularly in fundraising.

The project is a collaboration between the D.C. government and the nonprofit Building Bridges Across the River. The D.C. government has committed to providing $14.5 million of the $25 million construction price tag, Kratz said. An additional $15 million would provide operations funding.

Kratz said a capital campaign is underway and having a design and architecture team in place would make the pitch to potential donors more effective.

“No one has written me a seven-figure, eight-figure check, but we didn’t expect that,” he said. “The difference now is we have something that people can see and feel and touch.”

For years D.C. officials have been trying to narrow gaps in economic and health outcomes that have led many residents of Wards 7 and 8 — which comprise the neighborhoods east of the Anacostia — to feel left behind.

Toni L. Griffin, director of an architecture center at the City College of New York, served as deputy planning director under former mayor Anthony Williams when the District launched the Anacostia Waterfront Initiative, a wide-ranging effort to improve the city’s connection with the river.

Griffin also served on the five-member jury that selected OMA/Olin for the bridge park project.

“They researched and understood the ecological context of the Anacostia River, but also the social and economical context of the Anacostia River, all of which they tried to integrate,” she said.

She suggested trying to picture an environmental education center where children from both sides of the river could learn about the river’s wildlife by seeing it up close.

“Imagine being in a classroom and going out and being able to touch the river itself,” she said.

Follow Jonathan O’Connell on Twitter: @oconnellpostbiz