The Los Angeles River Revitalization Corporation used North Atwater Village park as a backdrop Tuesday to call attention to its proposal for a 51-mile greenway along the river.

The nonprofit development group, formed just over 2 years ago, is expanding plans to connect bike paths and walking trails along the waterway.

"We’re trying to build the river we want to see," said Omar Brownson, executive director of the corporation.

"We're not interested in transforming policy," he says, an explanation aimed at distinguishing his group from other river advocates. "We're interested in transforming the river."

A key first step in doing that for Brownson's group is called LaKretz Crossing. The project would use a multi-million dollar donation from philanthropist Morton LaKretz and other private monies for a bridge between Griffith Park and Atwater Village. The proposal has been approved by the L.A. Board of Public Works, but the L.A. City Council also has to give its approval.

The group's greenway vision is one of several overlapping ideas for the Los Angeles River. Brownson points to Friends of the High Line, the group that spearheaded a public-private partnership to develop a 1.6-mile park along the old New York Central Railroad spur.

While Brownson talks about ecological benefits, he says his corporation's goals are greater than that, encompassing social and economic values too. 

"Waterways are meant to bring people together, and they’re about connecting folks," Brownson says.

He believes development and revitalization already are doing that in L.A.

"You’re already seeing houses that had fences blocking access to the river, those fences are coming down," Brownson says. "People are opening up their porches to the L.A. River."