California voters will have a chance to approve $15 billion in bond funding to renovate aging school buildings in the state’s March primary under a bill Gov. Gavin Newsom signed Monday.

The measure designates $9 billion for preschool through high school, $2 billion for community colleges, $2 billion for the University of California and $2 billion for California State University.

“Our school facilities at all levels across this state are in subpar condition and need a major investment,” said Assemblyman Patrick O’Donnell, the Long Beach Democrat who wrote the bill. “It’s a good chunk of money for a huge challenge.”

About 6.2 million California children attend K-12 schools. The state Department of Finance projects that number will decline by 250,000 children over the next five years.

Still, many of the state’s schools are overcrowded and in disrepair, Newsom said, and some districts are seeing enrollment grow even as the state experiences an overall decline.

Schools need the money to build new classrooms and upgrade existing ones, O’Donnell said. The money also would be used to eliminate lead and asbestos from aging buildings.

“There’s still a deep and desperate need for modernization,” Newsom said, adding that the funding will prioritize poor districts with greater needs.

Two-thirds of California adults and 54 percent of likely voters say they support the measure, according to polling from the nonpartisan Public Policy Institute of California.

The measure passed the Legislature with overwhelming support, although some Republicans criticized the idea of funding school facilities by borrowing money through bonds, which could require $12.4 billion in interest payments, according to an Assembly committee analysis.

The $9 billion for pre-k through high school funding is divided into several categories: $2.8 billion for new construction, $5.2 billion for modernization, and half a billion each for charter schools and career technical education.

Some Democrats who supported the measure, Assembly Bill 48, argued there should have been a designated funding amount for preschool facilities.

Assemblyman Kevin McCarty, D-Sacramento, voted for the bond but said he was disappointed preschools didn’t get a guaranteed fund. He said he worries that will mean very little from the bonds will ultimately be spent on retrofitting classrooms for young children, who need smaller sinks and toilets.

“Many of us thought it was a glaring omission that there wasn’t a set aside for preschool,” he said.

In the end, there wasn’t enough money to cover everyone’s needs, especially as the state’s higher education advocates pushed for more funding, said Newsom, who often highlights preschool as one of his signature issues.

“We couldn’t do everything,” Newsom told reporters last week. “It was a tough tradeoff.”

Assembly Speaker Anthony Rendon, D-Lakewood, said he will push for more funding in next year’s budget for preschool facilities. He pointed to spending in this year’s budget as evidence of Newsom’s commitment to the issue.

This year’s budget included more than $30 million to expand enrollment in the state’s preschool program, more than $260 million for early learning and child care facilities and $195 million to train preschool teachers and caregivers. The budget also included more money for child care.

Newsom said preschool will remain a priority in 2020, but warned that next year’s budget will be less flush with cash as the economy slows.