Construction of the $500 million Obama Presidential Center will have an “adverse impact” on historic Jackson Park that must be mitigated, a federal review has concluded.

In a report triggered by Jackson Park’s listing on the National Register of Historic Places, the Federal Highway Administration homed in on the negative impact the four-building complex would have on the majestic Midway Plaisance and the Jackson Park Historic Landscape District.

The project would diminish the “the historic property’s overall integrity by altering historic, internal spatial divisions that were designed as a single entity” by renowned landscape architect Frederick Law Olmsted, the FHA concluded.

It also concludes the “size and scale of new buildings” would “diminish the intended prominence of the Museum of Science and Industry building and alter the overall composition and design intent of balancing park scenery with specific built areas.”

The release of the report triggers a 30-day public comment period.

“The changes impact how Jackson Park and the Midway Plaisance reflect conscious decisions made by the Olmsted firm in determining the organization, forms, patterns of circulation, relationships between major features, arrangement of vegetation, and views,” the report states.

“The combined changes diminish the sense of a particular period of time within the historic property and impact the integrity of feeling.” The project would, therefore, alter “characteristics of the historic property that qualify it for inclusion in the National Register” and require “deviating from the simple formality of open space that reflects the historic design principle of informal symmetry and balance in design.”

The finding puts pressure on the Obama Foundation to find a way to “resolve adverse effects” and turns up the heat on Mayor Lori Lightfoot to order the foundation to make those changes.

“The Obama Foundation has yet to show any interest in compromising on any of this. It may take [Lightfoot] to bring them to the table,” said Margaret Schmid, co-president of Jackson Park Watch.

“It means there are lots of new obstacles facing this proposal. A big question is, does Chicago want to go on record as having allowed a project that has major adverse impacts on this important historic park or can the project be redesigned to be compatible with this historic landscape?”

Asked if she will use her formidable clout to force the Obama Foundation to make changes, Lightfoot said: “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.

“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.”

The Obama Foundation issued its own statement calling Jackson Park a “majestic place with a rich history that we have embraced throughout our design process.”

“We look forward to hearing from the community about ways we can continue to work together to honor the history of Jackson Park and bring the Obama Presidential Center to Chicago’s South Side,” the foundation said.

Shortly before leaving office, former Mayor Rahm Emanuel, who served as Obama’s first White House chief of staff, pushed through a revised master agreement for the Obama Presidential Center to lease 19.3 acres of city land to the Obama Foundation for 99 years for the token price of $10.

The land transfer was contingent on the Obama Foundation’s ability to raise enough money to build the center and establish an endowment to cover maintenance and operations.

In addition to the master lease, aldermen also approved controversial road closures to pave the way for construction of a complex that will include a new branch of the Chicago Public Library, but none of Obama’s official documents.

The traffic plan includes closing the southern portion of Midway Plaisance Drive as well as Cornell Drive.

That would send southbound traffic from Cornell Drive to Stony Island Avenue, which would be widened, along with the northern portion of Midway Plaisance Drive.

The city has also made a commitment to use $172 million in state funding to widen Lake Shore Drive between 57th Street and Hayes Drive to accommodate the closing of Cornell Drive.

Schmid said the Obama Center “could be redesigned to be compatible” with Jackson Park. But it would require shrinking a 23-story building to a size “no taller” than the Museum of Science and Industry; maintaining “as many mature trees as possible;” and keeping Cornell Drive open and making it four lanes throughout, but slowing the speed limit to “end the threat of traffic overflow to surrounding neighborhoods.”