Beginning Oct. 1, low-level criminals will begin serving their time at the county jail instead of state prison. That will save California money and help meet a federal court order to reduce its prison population.
The problem is the state budget only pays for the inmate shift for the first year.
"It's worrisome because we have nowhere to put them and nobody to supervise them," said Nick Warner of the California State Sheriff's Association.
Warner said the prisoner shift is a good plan because with a 70 percent recidivism rate, the current system isn't working. But money will determine its success.
"Properly funded and with stability in that funding, locals can and will do a better job," Warner said. "Defunded or unfunded, this will be a criminal justice nightmare."
The possibility of a nightmare is why victims' rights groups are also worried.
"In about three years, an estimated 100,000 criminals who would have served time in a state prison are serving their sentence in a county jail."
With many local jails already crowded, some of those inmates may be let go to make room for the new state prisoners.
"We have a poor economy. We have no jobs. So what are these people who are coming out and not rehabilitated, what are they going to do? Go back to their lifestyle," said Harriet Salarno of Crime Victims United.
Since Republicans blocked the governor's plan to extend temporary taxes to pay for it, he vows to put a measure on the November 2012 ballot asking voters to guarantee funding with a Constitutional Amendment.
"I am not going to be stymied by a minority opposition," Brown said. "Thank God we have the initiative process."
The governor is also expected to ask voters to approve tax increases to help keep the prisoner shift plan intact.