Portland officials said Wednesday that they hope to build upon the recent debate over the fate of Congress Square Plaza as they study how to improve the city’s use of open space, whether for additional parks or affordable housing.

City officials Wednesday officially announced an initiative to take stock of Portland’s public lands in order to develop a long-term vision – or comprehensive plan – for those areas. The city is partnering with two nonprofit organizations, Portland Trails and The Trust for Public Land, to complete the assessment, which will also examine ways that other communities finance their parks and open-space programs.

The groups plan to solicit suggestions from local residents during meetings this fall.

“This gives us an opportunity to be proactive,” Portland Mayor Michael Brennan said during an event at the Ocean Gateway terminal, located near the start of the city’s popular Eastern Promenade Trail.

“This gives us the opportunity to sit down collectively as a community and to start having a discussion moving forward, as opposed to being in a position where we are reacting to a development proposal, development pressures or financing issues that are unexpected,” Brennan said.

The initiative comes roughly one month after city voters approved a referendum question that gives residents more say over future proposals to sell 60 city-owned parks, plazas and other public spaces. That referendum grew out of a controversial attempt by city officials to sell two-thirds of Congress Square Plaza – also known as Congress Square Park – to the redeveloper of the Westin Portland Harborview Hotel.

Following the referendum, that sale is up in the air and would likely require voter approval to move forward – a requirement added by the June 10 referendum. But Brennan and other speakers on Wednesday said they saw the ballot box issue as part of the broader conversation.

“There are commonalities in that we are talking about a public space, what that space looks like today, what we want it to look like tomorrow and what the relationship is for people in that corner” of the city, said Wolfe Tone, state director of The Trust for Public Land. “That’s the same context for the larger conversation. We have not linked them yet. But the methods, the thinking and sort of the approach apply to both.”

The organization Friends of Congress Square Park submitted the petition signatures in January that triggered the referendum. Later that month, Brennan used his annual State of the City address to discuss the need for an inventory of city land holdings and a “thoughtful” discussion about which properties should be protected and which could be developed.

Brennan said Wednesday that the June vote and preceding debate added “urgency and focus” to the discussion over open space. David LaCasse, a leader in the campaign to protect Congress Square Park, agreed.

“I think the energy of the referendum helped this a lot,” LaCasse said.

But Brennan said the open space initiative should also allow the city to examine other issues, such as affordable housing.

One way that Brennan said the city can help encourage development of affordable housing – a major concern in Portland’s tight and costly rental market – is to situate projects on city-owned land.

“So at the same time we are looking at open space and we are looking at public space, we are also looking at higher uses of space that the city owns for other issues that we have in the city,” Brennan said.

Kara Wooldrik, executive director of Portland Trails, said her organization plans to begin holding community meetings this fall as the group works toward meeting current open space needs and being in a better position to take advantage of future opportunities.

The initiative will be financed in part by an $18,000 grant to Portland Trails from the Lerner Foundation.