Members of the Cook County Sheriff's Department walk out of the Cook County Jail Tuesday in February 2006 in Chicago.

Chicago’s Cook County Jail, a harsh holding cell stuffed with up to 11,000 prisoners at any given time, is about to become even more crowded, according to The Chicago News Cooperative.

Tom Dart, The Cook County Sheriff, told The Chicago News Cooperative on Monday that of those 11,000 prisoners, about 2,000 have some form of serious mental illness. But he fears the situation could get much worse: Chicago has plans to shutter half of its 12 city-run mental health centers by the end of April in a bid to save $2 million, and that could leave many mentally ill patients without the treatment they need.

“It will definitely have a negative impact on jail populations,” Dart told The Chicago News Cooperative. “It will have direct consequences for us in my general jail population and some of the problems I have here, because a lot of the people with these issues act out more, as you would expect, so that’s a direct consequence.”

Without resources to treat them, those with mental health issues are more likely to have run-ins with the police, reported The Chicago News Cooperative.

Related: For mentally ill inmates, care behind bars can be lacking

“It’s going to increase the number of calls they get,” Amy Watson, associate professor at the Jane Addams College of Social Work at the University of Illinois, Chicago, said of the Chicago Police Department, “because it is the only place left to call.”

It costs about $143 per day to house a typical detainee at Cook County Jail, the media organization reported. To house a detainee with mental health issues costs two to three times as much, the sheriff said.

More content from msnbc.com and NBC News

• Making a Difference: Kids fishing for (and catching) success
• Rev. Graham: Obama seen as 'son of Islam'
• Lawmaker: 'Radical' Girl Scouts out to destroy American values
• Where do problem teachers go? LA's 'rubber room'