A coalition of community groups active in affordable-housing and economic-development initiatives on the South Side voiced concerns Thursday that their input on the Barack Obama Presidential Center library will be drowned out by people with clout.

The coalition — which includes the Kenwood Oakland Community Organization and Southside Together Organized for Power — wants the Obama Foundation to sign a “community benefits agreement” to guarantee the hiring of local workers and construction companies for the library project, as well as establish plans for affordable housing as the neighborhoods around it are expected to get pricier.

“I want it in writing,” said Michele Williams, 74, a KOCO member who lives in an affordable-housing high rise near the library site. “If you get it in writing then you have to live up to it.”

The coalition’s press conference was prompted by the influential Chicago Community Trust’s decision to award a $250,000 grant to help create a separate not-for-profit that also would aim to ensure that South Side residents would benefit from the library, to be located in Jackson Park.

The trust is overseen by a who’s who of powerful Chicagoans, from former Obama Chief of Staff Bill Daley to Chicago Bulls president Michael Reinsdorf. One of its partners in creating the non-profit is the Rev. Byron Brazier, leader of the 20,000-member Apostolic Church of God, a few blocks west of the library site. The church is among the biggest owners of land near the site.

Reached after the press conference, Brazier said the church has no plans to sell any of its property, much of it used for parking. He also said that he, too, wants what’s best for the neighborhoods around the library, but he doesn’t think the Obama Foundation should have to put anything in writing.

“The reason why I am not for a contractual benefits agreement . . . I trust the Obamas,” Brazier said. “I’ve said that publicly. . . . And I don’t believe the Obamas place the library in Jackson Park for it not to benefit the community.”

The Chicago Community Trust is paying Next Street consultants $250,000 to study how to incorporate the Obama library into the surrounding community and help existing residents. Ultimately, the trust wants to bring a variety of community leaders onto the new non-profit’s board, said Joanna Trotter, who’s helping spearhead the project for the trust.

The non-profit doesn’t yet have a name. A meeting that’s expected to shed more light on plans for it is set for 8 a.m. Saturday at the University of Chicago’s School of Social Service Administration, 969 E. 60th St, as part of the Woodlawn Community Summit. Trotter and Obama Foundation representative Michael Strautmanis are set to speak at the event, which is being billed as an “open forum” for community members.

So far, KOCO, STOP and the other organizations trying to get the Obama Foundation to sign the hiring and affordable-housing plan aren’t impressed.

“Come to the people who’ve been been working on this,” KOCO member Jeanette Taylor said. “They don’t need to create an organization to try to undermine the community.”

An Obama Foundation official responded to those residents’ concerns in a prepared statement that read in part, “We commend the work being done by the dozens of community leaders, residents and activists who are working together to foster the transformative economic growth that will have a lasting impact on Chicago’s South Side. The Foundation team looks forward to continuing to work closely with the entire community in this process.”