SIOUX FALLS, S.D. — South Dakota is bracing for a steep rise in its prison population over the next decade, and officials now face the financial consequences of recent tough-on-crime legislation. A projected 34% increase in inmates may require the state to invest up to $2 billion in new correctional facilities by 2035, even as crime rates across the country trend downward.

The first step is already underway: Lawmakers have earmarked $600 million to replace the aging South Dakota State Penitentiary in Sioux Falls. That alone marks one of the largest taxpayer-funded construction projects in the state’s history.

The surge in inmate numbers stems in part from a 2023 law requiring certain violent offenders to serve their full prison terms without the possibility of parole. A report by Phoenix-based consulting firm Arrington Watkins Architects, commissioned by the state, estimated the need for an additional 3,300 beds statewide to accommodate the projected growth.

“Crime has been falling everywhere in the country, with historic drops in crime in the last year or two,” said Bob Libal, senior campaign strategist with The Sentencing Project. “It’s a particularly unusual time to be investing $2 billion in prisons.”

South Dakota’s incarceration rate—370 per 100,000 residents—is higher than that of neighboring states like North Dakota and Minnesota, which fall below 250 per 100,000. Roughly half of the projected inmate population increase is tied to stricter sentencing laws, while nearly 40% of admissions in 2024 involved parolees returning to prison—mostly for technical violations.

Criminal defense attorney Ryan Kolbeck pointed to gaps in support for inmates struggling with substance use. “People are being sent to the penitentiary but there’s no programs there for them. There’s no way it’s going to help them become better people,” he said. “Essentially we’re going to put them out there and house them for a little bit, leave them on parole and expect them to do well.”

The prison system also reflects deep racial disparities. Native Americans, who make up about 10% of the state’s population, represent 35% of its incarcerated population, according to the Prison Policy Initiative.

The replacement of the 144-year-old state penitentiary is just one piece of the puzzle. A legislative task force led by Lieutenant Governor Tony Venhuizen is expected to present a comprehensive prison plan in July.

“One thing I’m trying to do as the chairman of this task force is keep us very focused on our mission,” Venhuizen said. “There are people who want to talk about policies in the prisons or the administration or the criminal justice system more broadly, and that would be a much larger project than the fairly narrow scope that we have.”

Still, some say infrastructure alone won’t solve the problem. Former warden Darin Young believes the state needs to allocate up to $300 million toward addiction and mental health treatment. “Until we fix the reasons why people come to prison and address that issue, the numbers are not going to stop,” he said.

Even with new construction, criminal justice experts say without reform, the state will soon be back at square one.

“We might be good for a few years, now that we’ve got more capacity, but in a couple years it’ll be full again,” Kolbeck said. “Under our policies, you’re going to reach capacity again soon.”

Originally reported by The Associated Press in Finance & Commerce.