Julie Small | KQED

At Thunder Road Adolescent Treatment Centers in Oakland, 16-year-old Eric enjoys tending roses in a small patio.

“It don’t got a lot of roses yet but they’re growing,” he says. It could be a metaphor for his own life.

He just completed 60 days of residential addiction and mental health therapy instead of serving time at juvenile hall. We’re calling him “Eric” to protect his identity.

A year and half ago, he robbed a woman for her purse and phone.

He says, “I was just young and not thinking and I didn’t know I was going to get caught.”

Eric was convicted of robbery and placed on probation, which he violated by using drugs. He says he turned to marijuana and alcohol to escape problems he was having with his mom.

“It’s been hard, just using and going downhill.”

Eric has spent time in juvenile hall before, and was headed there again, when he was offered an option to go into treatment instead. This type of program is exactly what voters were promised would get more support under Proposition 47.

The 2014 measure reduced penalties for drug offenses and other low-level felonies with the promise of saving hundreds of millions of dollars a year on prisons. Those savings will be used for drug treatment and other rehabilitation programs, starting this year. But now advocates are wondering: What happened to the money?

“We definitely believe that there are more savings than is currently indicated is going to be in the budget,” says Lenore Anderson, executive director of Californians for Safety and Justice, who co-authored Prop. 47 with San Francisco District Attorney George Gascón.

Anderson was stunned in January when the Brown administration announced that the state saved just $29.3 million from the measure this fiscal year — a fraction of the “low hundreds of millions” that had been predicted in the voter guide.

“We‘re very comfortable with the methodology and the calculations that we’ve used,” says H. D. Palmer, a spokesman for the state Finance Department. “We think it provides a realistic expectation — not only to the Legislature but to the public — in terms of the savings that are going to be generated by this proposition.”

Palmer says the savings estimate is based on the most recent data from the California Department of Corrections and Rehabilitation on how many inmates were affected by Prop. 47 — and in what types of beds they would have been housed.

According to prison officials, 4,700 fewer people were in state prison during fiscal year 2015-16, the majority of them saving the state $9,000 each.

Aaron Edwards, with the Legislative Analyst’s Office, thinks the state saved a lot more than that.

“The bottom line here is that we think the administration has underestimated the savings from Prop. 47 by around $100 million.”

California has been contracting thousands of beds with private facilities or prisons in other states in order to comply with a federal court order to cap the population.

Given those conditions, Edwards thinks corrections officials would have sent those extra 4,700 inmates to private institutions or prisons in other states — not to crowded state facilities.

“When you look at those factors and you look at what the trend line was, it appears pretty clear to us that we would have had to go out and get several thousand contract beds, had this measure not passed,” he says.

Edwards estimates prisons saved $29,000 each on those contract beds.

How much Prop. 47 saved and how much of those savings will go to community programs is the focus of a Senate hearing Thursday.

Supporters are pushing to get the governor to increase the allocation when he revises his budget in May. Just how many people will be served by Prop. 47’s funding will be sorted out in Sacramento over the coming months.

Prop. 47 co-author Anderson says California has been slow to shift funds from prisons and jails into programs that can reduce incarceration:

“We are failing to do what we know we could do to prevent people from falling through the cracks: to invest in mental health and drug treatment at the scale that it’s needed at the community level before people are even in the criminal justice system.”

Armando Corpus, an addiction specialist at Thunder Road, says whatever Prop. 47 ultimately yields, he hopes the teenagers he treats receive a fair share.

“There aren’t a lot of open arms for kids with drug charges against them or a history of drug use,” Corpus says. “There’s not a lot of folks reaching out to them. Our kids really deserve that shot if they can get it.”

Corpus says many teenagers get swept up in the criminal justice system largely because of addiction or mental illnesses like depression, bipolar disorder, schizophrenia and post-traumatic stress disorder.

“The kids who get sent here have tougher cases against them, a lot more family dysfunction, a lot more history of abuse and neglect,” Corpus says.

An estimated two-thirds of the teenagers treated at Thunder Road have been physically abused. Roughly a quarter have been sexually abused. Many live in homes where multiple family members are abusing drugs.

Our 16-year-old Eric plans to live with his grandmother and a younger sister after treatment.

“They didn’t give up on me,” he says. “Since I came here, they got hope in me. They know that I’m trying to change and become a better person.”

Residential Treatment Rare

Residential treatment programs are the most expensive, the hardest to fund and the most critical, says Dee Gagnon, admissions director at Thunder Road. “With mental health and substance abuse, most people don’t get better on their own.”

Thunder Road helps teenagers develop more positive coping skills to help keep them out of jail and prison. The nonprofit also works to improve relationships through family counseling. It’s the last remaining residential treatment program for adolescents in the San Francisco Bay Area.

Thunder Road almost closed this year after Sutter Health decided to drop the program because it had been losing money. Just before the doors were due to shut, the nonprofit Bay Area Community Services (BACS) took it over.

“We are very grateful they did,” says Gagnon.

BACS helps people coming out of prison find housing and jobs.

Thunder Road hopes to ramp up staffing later this year.

Copyright 2016 KQED. To see more election coverage, visit kqed.org/election2016.