Only one of two dueling measures to reform the pensions of San Francisco city workers was passed by voters on Nov. 8 — a collaborative proposal crafted by various city officials and labor and business leaders.

Proposition C was approved and put on the ballot by interim Mayor Ed Lee and all 11 members of the Board of Supervisors, and was passed by about 69 percent of voters, according to complete unofficial election results.

The measure, which only needed majority approval, is expected to save the city about $1.3 billion over the next 10 years, said Nathan Ballard, spokesman for the pro-Prop C campaign.

Proposition D, backed by Public Defender and mayoral candidate Jeff Adachi, who gathered signatures to put it on the ballot, called for higher pension contributions from city workers but got the support of only about 34percent of voters.

“San Francisco voters chose the path of collaboration instead of the path of confrontation,” Ballard said.

Prop C “goes a long way toward addressing our unfunded pension liability, and does it fairly, with the participation of the people that are most affected — the employees of San Francisco and the taxpayers of San Francisco,” he said.

Colin Dyer, spokesman for Adachi’s mayoral campaign, said Adachi “of course is disappointed to see that Proposition D isn’t going to pass.”

However, Dyer said Adachi is considering it “a small victory” that “Prop C was initially proposed because of his work over the past two years” on the pension issue.

Adachi proposed a similar measure, Proposition B, on last year’s November ballot, but that, too, was voted down by more than 57 percent of voters. Dyer said Adachi wanted more extensive reform but this year’s Prop C “is on the right track.”