A similar plan has been floated in Kern County, north of Los Angeles. But the sheriff there, Donny Youngblood, has opposed the idea, saying it could cost more than it would bring in.

“I’m not against it, believe me. I think in a perfect world, if all of them could pay, I would be in favor of it,” Sheriff Youngblood said. “It’s not so much that I am concerned about the fairness, although there is an aspect of that. It’s simply not a road I think is worth going down right now.”

But, he added, “If it’s successful, there will certainly be others who follow, because we are all looking for more money.”

With five jails spread throughout the county, Riverside, which is east of Los Angeles, has already reached 93 percent of its capacity, up from 85 percent before the state began moving prisoners in October. Those inmates have much longer sentences — they will stay in county jail an average of two years, more than double the length of stay for typical county inmates.

“Overcrowding is one of my top concerns,” said Jerry Gutierrez, a chief deputy at the Riverside County Sheriff’s Department who oversees the jails. “You have an overcrowded facility, and it just builds up the tensions. It becomes a longer wait for the showers — not everybody is going to get in there. There’s less time outside of cells, and it demands more resources we may not have.”

The effects of the state’s transfer plans are not limited to the jails. For years, the state has relied on inmates convicted of nonviolent crimes to join crews that fight wildfires across the state. But because of the shift of so many prisoners to county jails, the firefighting force will begin to shrink this year. (Counties can send prisoners to the fire camps, but the state will charge those that do about $46 per prisoner per day, reducing the incentive.)

Mr. Stone, a Republican who has been so critical of the Democratic-controlled Legislature that he has called for the secession of the eastern part of the state, said the state’s plan amounted to a “partially unfunded” mandate. Riverside officials have said they were getting enough money from the state now, but they worry about next year, when the guarantee for a financing source expires and voters will be asked to approve tax increases to ensure that services do not erode.