San Francisco has a staggering $5.8 billion pension liability, and a series of retroactive benefit increases approved by voters over a dozen years is largely to blame, according to a recently released civil grand jury report.

That generosity is contributing to an eye-popping increase in the public payroll. The grand jury found that the cost of city salaries and benefits, which include pensions, has grown by 33 percent over the past decade — and it’s expected to keep up that pace for at least five more years. That will add another $698 million to the public tab.

And while these estimates come right out of the city’s budget forecasts, said grand jury member Christopher Bacon, “it’s a bigger problem than I think the city has wanted to face.”

According to veteran City Hall watcher and Chamber of Commerce Vice President Jim Lazarus, the mounting retirement expenses “for the foreseeable future (will) require a substantial general fund payment into the pension system.”

That, in turn, could force the city to cut services, and it may “affect the number of employees ... and the wage and benefit packages (the city) can afford,” Lazarus said.

It’s worth noting that the city has paid almost twice as much in pension contributions as workers over the past decade. In that time, the city’s annual contribution has more than tripled, to $526.8 million.

At the heart of the city’s pension troubles, the civil grand jury found, are 10 ballot measures approved by voters between 1996 and 2008 that allowed for retroactive increases to employee retirement benefits.

“These retroactive increases were very expensive gifts to employees and retirees from taxpayers, paid for with money borrowed at a high interest rate from the retirement system, and paid back over 20 years by taxpayers,” the grand jury said.

Among them was Proposition H in 2002 to boost police and firefighter pensions — which had the backing of everyone from the entire Board of Supervisors to Sen. Dianne Feinstein and Rep. Nancy Pelosi. Their ballot argument, plus a statement from then-Controller Ed Harrington, said there would be “no costs to taxpayers for at least 10 years,” thanks to the pension system’s “large surplus.”

If the retirement surplus was “ever exhausted,” police and firefighters would be required to negotiate with the city “to pay for the added benefit themselves,” the advocates said.

That never happened, we’re told — although police and firefighters now pay a higher percentage into their pensions.

After reviewing the impact from the wave of retroactive pension increases, the grand jury concluded that a series of mayors, members of the Board of Supervisors, city controllers and retirement board members “did not fulfill their responsibility to watch out for the interests of the city and its residents.”

City Controller Ben Rosenfield, while acknowledging the seriousness of the rising pension debt, blames more recent events for the city’s predicament. Pension recipients are living longer, he said, and the courts overturned a 2011 city initiative that would have limited cost-of-living increases for retirees — delivering a $1.3 billion blow to San Francisco’s pension savings.

And while the grand jury also points to $1.4 billion in investment losses dating back to the economic crash of 2008, city retirement board member Victor Makras says the agency’s own poor investment strategies are the real issue.

“We can’t blame (the recession) anymore,” he said. “We are responsible for prudently investing.”

Downsizing: When Carol Christ took over as UC Berkeley’s chancellor last week, not only did she become the first woman to occupy the job — she also broke with tradition by deciding not to move into the gated campus mansion made notorious by the costly spruce-up by her predecessor, Nicholas Dirks.

More than $1 million was spent in recent years remodeling University House for Dirks and his professor wife, Janaki Bakhle — including $247,000 authorized by former UC President Mark Yudof to renovate the kitchen, paint the place, refinish the floors and install new window coverings.

The university also spent close to $700,000 — 2½ times the original budget — to install a security fence after protesters sprayed graffiti on the house.

Plus, Bakhle swapped nine Persian rugs for six newer ones — at a net cost of at least $90,000.

University House has been home to UC presidents and Berkeley chancellors since 1911 — so why isn’t Christ moving in?

“Because I have a lovely house in Berkeley that I love,” she told The Chronicle’s Nanette Asimov. “But I will use University House extensively for entertaining.”

Christ was promoted from her job as interim executive vice chancellor and provost at Berkeley and will earn $531,939 in her new position — the same salary Dirks was making. She says that in addition to giving up the keys to University House, she and the rest of the campus’ senior leadership will skip a raise next year as UC Berkeley deals with a $110 million deficit.

San Francisco Chronicle columnists Phillip Matier and Andrew Ross appear Sundays, Mondays and Wednesdays. Matier can be seen on the KPIX-TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call (415) 777-8815, or email matierandross@sfchronicle.com. Twitter: @matierandross