Despite an unexpected $3 billion infusion in K-12 revenue for the coming school year, schools throughout the state are honing their electronic blue pencils to slash budgets.

Gov. Jerry Brown’s proposal to boost school funding to $56.7 billion “is not likely to be enough to mitigate any of the other crises districts are facing,” said Mary Ann Dewan, interim superintendent of the Santa Clara County Office of Education.

In San Jose, the Oak Grove School District still plans to close three to five elementary schools in the fall. The East Side Union High School District board resolved to eliminate 66 jobs over two years. And Oakland Unified isn’t reversing the $9 million in painful cuts for this school year — although state funds could soften $11.2 million in trims laid out for next year.

As they cut spending, school officials will face a tough sell to constituents wondering what happened to the new “extra” cash — especially when the combination of federal, state and local funds for K-12 are expected to total a record $95.6 billion in the next fiscal year, a 2.5 percent increase. That comes to $16,085 per pupil.

However, of the $3 billion excess designated for schools, half is for cost-of-living increases and the other half simply completes a 2013 promise two years early — to restore schools’ pre-recession purchasing power. For a decade schools have been struggling to catch up to where they were in 2007-’08.

Meanwhile, costs of benefits, salaries and operations have escalated. And under a deal to help keep the state retirement systems afloat, school districts must devote a greater chunk to pensions — 16.3 percent of teacher payroll next year and likely a similar percentage for support-staff pensions.

In recent years, many districts granted employees generous raises to make up for recession-era frugality. Some like Oak Grove are being squeezed by declining enrollment, forcing state revenue to plummet faster than the districts can reduce costs.

Brown’s proposal “only takes care of the problem for one year,” wrote Rose Ramos, chief business officer of the Mount Diablo Unified School District in Concord.

As they take up next school year’s budgets, districts like East Side Union could choose not to lay off as many employees, Superintendent Chris Funk said, but “all that does is kick the can down the road a year or two.”

If the budget that emerges in June follows Brown’s proposal, “It will help us just a little bit now,” said Jeff Bowman of the Cupertino Union School District, which faces cutting $5 million in 2018-’19, after trimming $2.6 million last spring. “We’re still behind.”

Cupertino doesn’t receive nearly as much state aid as other districts. Under Brown’s 2013 reform — dubbed the Local Control Funding Formula — schools that have a higher number of harder-to-educate students receive more funds. Ravenswood in East Palo Alto and Alum Rock in San Jose are among the top recipients in the state in aid per student. At the bottom are those in wealthy enclaves with few poor and English-learner students: San Ramon Valley Unified, Walnut Creek Elementary, Belmont-Redwood Shores, Lafayette, Moraga and Orinda in Contra Costa County.

Under Brown’s plan, San Ramon would receive an additional $8 million in ongoing funds and $9 million in one-time funds, according to spokeswoman Elizabeth Graswich.

While she welcomed the governor’s budget, “It is too early for SRVUSD to provide any details of how these funds could be used.”

School officials also will have to explain how the annual increases that schools enjoyed in recent years are about to disappear, now that Brown has achieved the goals of his Local Control Funding Formula.

“I think LCFF was his legacy, and he wanted to make sure it was fully implemented before he left office,” said Ron Bennett, CEO of School Services of California, a firm that offers fiscal advice to most of California’s 1,000 school districts.

But masked by the state’s $15 million projected surplus and the fat boost in education funding in Brown’s last year in office, Bennett said, the governor failed to restore education spending to the premiere status it held in his youth.

“I’m disappointed that absolutely nothing has been done to move California back on par with higher-spending states,” Bennett said.

While high spending doesn’t guarantee high achievement, Bennett points out parallels between low spending and low achievement. California is about 45th among states in per-pupil education spending, he noted, and at a similar level in achievement on standardized tests.

Measured by ratios of students to teachers, administrators, librarians, counselors and psychologists, he said. “California is a high-tax state,” he said, “with a low commitment to public education.”

But pointing that out to the public is a hard sell, as is explaining that a school district is cash-poor because of its demographics. “Overall, it is very confusing for families,” Bowman said. “It’s confusing for the educators who live it every day.”