Mayor Lori Lightfoot was accused Wednesday of pushing an “engineered agenda with a pre-determined outcome” at a recent discussion of ways to mitigate the “adverse impact” that the Obama Presidential Center would have on historic Jackson Park.

The sharply-worded letter was signed by the leaders of five nonprofits with a vested interest in minimizing the impact of the $500 million showcase project.

They are: Ward Miller, executive director of Preservation Chicago; Juanita Irizarry, executive director of Friends of the Parks; Michal Safar, president of the Hyde Park Historical Society; Karen Rechtschaffen, co-chair of Save the Midway and Margaret Schmid, co-founder of Jackson Park Watch.

The letter took aim at an Aug. 5 meeting hosted by the city after a Federal Highway Administration review concluded the Obama Presidential Center would have an “adverse impact” on historic Jackson Park, designed by Frederick Law Olmsted.

“Under the federally-mandated review process, there should be a full study and consideration of ways, first to avoid, then to minimize and then, as a last resort, to mitigate the adverse effects of the plans to build the OPC in historic Jackson Park,” the letter states.

Instead, “virtually all the focus” of the City Hall presentation was on “how the city was looking at mitigation. ... They completely skipped consideration of avoidance and minimization,” the letter states.

As a result, the meeting “felt a lot like meetings past: an engineered agenda with a pre-determined outcome, paying lip service only to the idea of an open meeting,” according to the letter.

“Your administration has promised transparency, accountability and openness to community input. Nothing of the sort occurred,” the letter states.

“Such a narrow approach reflects the type of pre-determined, non-transparent and wholly improper manner of governing that prior administrations routinely utilized and which you have sworn to do away with.”

Lightfoot was sharply critical of Mayor Rahm Emanuel’s top-down approach. She has promised to listen more, talk less and be more collaborative before making decisions on major development projects.

“During and after the mayoral campaign, the people of Chicago heard your message that a new day was here. One where the light would shine upon and impact projects like the OPC. The new day was not in evidence on Aug. 5,” the letter states.

The mayor’s office responded to the letter with a statement reiterating Lightfoot’s commitment “to ensuring that community voices will not just be heard, but included, as we move to build the new Obama Presidential Center.”

The process began last month, when the mayor began, what she called, a “new dialogue” about the impact of the Obama Center with area residents, community groups and elected officials.

It continued with the Aug. 5 “listening session” to discuss ... a separate federal review process.”

“Our administration is committed to hosting a series of forums that are meant to gain broad input on a number of topics related to the project — each of which will be equally essential as we work together to ensure this new community hub will create the maximum benefit for nearby residents, and the city at large,” the mayor’s office said.

Pressed further to articulate specific demands of the mayor’s office, Irizarry said the Obama Center should, “at the very least” trigger “development of 19.3 acres of parkland throughout the surrounding neighborhoods, including a baseball facility to replace the one that is being displaced.”

The parkland should be “part of a community benefits agreement” Lightfoot promised during the mayoral campaign, Irizarry wrote in an email.

Miller urged the mayor to consider an alternative site across the street from Washington Park and next to the Green Line station. The city, the University of Chicago and the CTA own nine-to-eleven acres of land there that could be used to build the Obama Center, he said.

“Not in an Olmsted Park. Not in a public park. Not overshadowing historic Jackson Park and the Museum of Science and Industry. Not take away green space and Olmsted park land from the people of Chicago,” Miller said.

“There’s so many ... negative adverse impacts, which are profound to the Jackson Park-Olmsted landscape that I don’t think there’s remediation possible...We’re talking about the loss of 2,000 trees. There will be no reflection of Olmsted’s vision in this park if both of these projects [Obama Center and golf course merger] go forward. That’s tragic.”

The federal finding put pressure on the Obama Foundation to find a way to “resolve adverse effects” and turned up the heat on Lightfoot to order the foundation to make those changes. The mayor is already under pressure to deliver on her promise of a community benefits agreement.

On the day the federal review was released, Lightfoot was asked whether she would use her formidable clout to force the Obama Foundation to make changes the foundation has resisted.

“I don’t think I should force anybody to do anything. But I will strongly weigh in about the need to engage community members about the remaining issues that they’re concerned about.”

City Hall is prepared to take on some of the responsibility for addressing the needs of South Side residents affected by the Obama Center, the mayor said that day.

“We’re not going to sit back passively and just be the facilitator or the conduit by which city approvals, licensing and so forth gets approved,” she said.

“It is a big honor and opportunity for us to have this presidential center coming to Chicago and particularly for the South Side. And I want to use that opportunity to make catalytic change in the trajectory of the quality of life for people in those neighborhoods.”