SPRINGFIELD — In his first State of the State speech, Gov. Bruce Rauner said he wants to end years of explosive growth and understaffing in Illinois' sprawling prison system.

Under a prison reform plan in the Republican governor's "Turnaround Agenda," Rauner called for a series of changes that could reduce the prison population by 25 percent over 10 years, while also ramping up hiring of prison guards.

"The conditions of our prisons are unacceptable," Rauner said during his Wednesday address. "Inmates and corrections officers alike find themselves in an unsafe environment. It's wrong."

Rauner, a Republican businessman from Winnetka, isn't the first governor to try to crack the code on the state's often politically challenging prison system.

Former Gov. Pat Quinn was tripped up early in his tenure when an early release program went awry. Quinn also oversaw the closure of prisons in Tamms and Dwight. Former Gov. Rod Blagojevich threatened to close Pontiac Correctional Center and move inmates into the now-federally owned prison facility in Thomson.

Former Govs. George Ryan and Jim Edgar pushed for the construction of numerous prisons at a time when the inmate population was growing.

If Rauner is successful in trying to tame the $1.3 billion agency, the state's current prison population of 49,000 inmates could be slashed by 11,000 inmates.

The move could ease crowding behind bars by putting 38,000 inmates into facilities built for 32,000 inmates.

At the same time, adding as many as 473 new correctional officers by July 2015 could reverse a trend that has seen the state pay out massive amounts of overtime.

Illinois Department of Corrections spokesman Tom Shaer said the new hires could put an end to as much as $60 million in overtime, resulting in a total net savings of $10.4 million in the fiscal year 2016 budget.

"The combination of crowded prisons and amount of overtime needed to staff the prisons is exactly why the department would welcome the types of reforms Governor Rauner is talking about," Shaer said.

Prison reform advocates say the governor's plans for the prison system have merit.

"Evidence shows that overreliance on incarceration for the past 40 years has undermined the fiscal and social health of our communities, drained our state and nation of critical resources and magnified racial and economic inequities without appreciably improving public safety," said Jennifer Vollen-Katz, interim executive director of the John Howard Association, a Chicago-based prison watchdog organization.

The American Federation of State, County and Municipal Employees union, which represents guards and other prison workers, also took a positive view of the governor's proposals.

"We're glad that the governor acknowledges the need for additional staff in Corrections and recognize what we have long underscored," AFSCME Council 31 spokesman Anders Lindall said. "The combination of several understaffing and overcrowding is dangerous for employees, inmates and, ultimately, the public."

Rauner's blueprint for change includes three main points, including:

• Reducing the penalties for nonviolent offenses.

• Changing the criminal code to have sentences better fit the crimes that are committed.

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• Expanding the Adult Redeploy program, which has successfully diverted 2,000 nonviolent offenders from prison by establishing financial incentives for counties to provide community-based treatment in lieu of incarceration.

"The governor's pledge to reduce Illinois' prison population reflects this consensus that mass incarceration is a problem in itself and not a viable answer to crime control," Vollen-Katz said.

But both the reforms designed to cut down on the number of inmates entering the system and the push to hire new prison guards face an uncertain future in the General Assembly.

Despite studies showing that there are better options to sending some criminals to prison for drug-related crimes, Illinois legislators have voted consistently for so-called "tough on crime" laws designed to appeal to a crime-weary public.

And the state's serious budgetary problems will put lawmakers in a tough spot trying to weigh whether to spend scant resources on new prison guards, education or health care.

Plus, Corrections officials have had a hard time hiring people to fill vacancies that occur in the prisons.

Shaer said the agency trained and hired 700 new correctional officers between October 2013 and September 2014. But the net gain in staff was just two workers because of a high number of retirements during the past fiscal year.

Like the Rauner administration, Vollen-Katz said the John Howard Association acknowledges that changes to the $1.3 billion agency won't occur overnight.

But, she said, "We are going to be watching each step of the way."