Capacity at the Cook County jail will be cut to 9,100 beds from 10,000, in a cutback expected to save up to $15 million a year.

Sheriff Tom Dart on Thursday announced the first significant cutbacks in decades at the jail, thanks largely to a reduction in crime.

One 600-bed building has already been closed, and another 300-bed building will be closed in April, Dart said. That will cut capacity to 9,100 and will likely mean Cook County jail will no longer be the largest single-site jail in the nation, the sheriff's office said.

"At a time when every government agency is looking for ways to cut costs and save taxpayer dollars, it makes no sense to keep half-empty buildings operating at full capacity," Dart said in a news conference at the once-notorious jail at 26th Street and California in Chicago.

He said this also lays a foundation to save more tax dollars in the future.

Charles Fasano, who recently left his position as director of the prisons and jails program at the John Howard Association of Illinois, a watchdog agency, said he was "delighted" by the announcement. "We've been recommending that for several years," he said.

Fasano praised Dart's work, but added, "He's been blessed that admission numbers are down."

The average daily population at Cook County jail peaked at 11,082 in 2002, when inmates were sleeping on the floors and the sheriff's office was straining under the decades-old Duran Decree on conditions at the jail. Yet, while 106,000 people were processed at the jail in 2004, last year that number dropped to 86,000, and the average daily population was 9,039.

Dart said the average daily population was 8,400 in February and stood at 8,600 as he made the announcement. That led him and jail director Tony Godinez to come up with an "under capacity" plan, a counterpart to the previous "over capacity" plan.

The division closings will allow 175 corrections employees to move to other posts and reduce overtime, Dart said. That could save $10.5 million in salaries and benefits and $2 million in overtime. Along with savings in utilities and maintenance costs and food, Dart said the cost reduction could approach $15 million a year.

He cautioned it was contingent on the jail population remaining low with no spikes in crime. He first mentioned the possibility of closing down divisions during the recent primary campaign, when he added that they could potentially be reopened in four or five days if needed.

According to the sheriff's office, Chicago has reported decreases in violent crime, property crime and crime overall in recent years, a trend general across the nation, despite the tough economy.