UPDATE: 4:24 p.m.

CHICAGO (CBS) — Bringing the Obama Presidential Library and Museum to Chicago might be a step closer to reality, as Mayor Rahm Emanuel unveilled an ordinance he hopes will help ease concerns of the Barack Obama Foundation.

Emanuel said he will not let, “This opportunity slip through Chicago’s fingers.”

“It is essential the president’s library is here in Chicago and not in New York,” Emanuel said.

The University of Chicago has submitted a bid for the library, but its two proposed sites depend on using land in either Jackson Park or Washington Park. The bid raised concerns with the Barack Obama Foundation, because the university does not own the land it wants to use for the library, and has not secured a commitment to acquire or control the property.

Emanuel’s ordinance is aimed at alleviating those concerns, by transferring at least 20 acres of Park District property in Jackson Park or Washington Park to the city, if the University of Chicago is selected to host the library. If another bid is selected, the Park District would keep the property.

Illustration of potential development on Stony Island Avenue, near one of two potential sites for the Obama Presidential Library, proposed by the University of Chicago. (Credit: University of Chicago)

Illustration of potential development on Stony Island Avenue, near one of two potential sites for the Obama Presidential Library, proposed by the University of Chicago. (Credit: University of Chicago)

For some, the move to use park land for the project is a problem.

“There are organizations across the country that are very concerned about the dangerous precedents that this kind of public land transfer sets,” said Cassandra Francis with the group the Friends of the Parks.

Francis says her group supports the library but this plan, combined with the mayor’s push to build a high school in a park and the Lucas Museum in open space raises red flags about future land use.

Emanuel doesn’t agree ,saying that those concerns can be addressed by creating new open space to replace the library land.

The University of Chicago is competing with the University of Illinois at Chicago, Columbia University in New York, and the University of Hawaii in Honolulu to host the Obama Library.

The U of C’s plan would call for the library to be built on 3 to 5 acres in Jackson Park or Washington Park. The agreement with the Emanuel administration would require the remaining 15 to 18 acres of the library site to be open green space. The city also would have to replace the open space given up for the library building by providing an equal amount of green space elsewhere in the city.

Illustration of potential development on Garfield Boulevard, near one of two potential sites for the Obama Presidential Library, proposed by the University of Chicago. (Credit: University of Chicago)

Illustration of potential development on Garfield Boulevard, near one of two potential sites for the Obama Presidential Library, proposed by the University of Chicago. (Credit: University of Chicago)

Plans to build on land within either of the South Side parks has drawn serious opposition from the Friends of the Parks, which said it would create a slippery slope, and potentially open other Park District land to private development.

However, the City Council is expected to approve the mayor’s proposal to shore up the University of Chicago’s bid.

The UIC’s proposed library site would be in the North Lawndale neighborhood, on 23 acres of land already owned by the city, and the mayor already has committed to donating the land to UIC if its bid is selected.

Even with Emanuel attempting to clear the way for the University of Chicago’s bid, backers of the UIC bid continued to push for the North Lawndale neighborhood to be considered for the library.

“We wish University of Chicago well, but we don’t want people to forget that we’re here. We have a 23-acre site right behind us. There are no issues of site control. The only thing we need is for Mayor Emanuel to call a hearing,” said Valerie Leonard, a supporter of the North Lawndale bid.

So far, however, the only public hearings regarding the Obama Library have been held on the South Side, and focused on the University of Chicago’s bid.

Ultimately, the decision on which bid to accept for the library would be up to President Barack Obama and First Lady Michelle Obama.

Map of the two proposed sites for the Obama Presidential Library presented by the University of Chicago. (Credit: University of Chicago)

Map of the two proposed sites for the Obama Presidential Library presented by the University of Chicago. (Credit: University of Chicago)