With news that 80 Oakland Police Officers will be laid off in a matter of hours, Oakland Police Officers Dometrius Fowler (l to r) and Paul Phillips report for third shift duty on Monday July 12, 2010 in Oakland, Calif. Both officers, who have been with the force in Oakland for 2 1/2 years, worry if these layoffs happen that they might be next to go. Fowler worries that crime will increase and says it is the mismanagement of money that is the real blame for this problem. (Mike Kepka / The Chronicle)

Oakland's police union said Monday that its members agreed to pay more into their pensions and accepted a later retirement for new hires, concessions that depend on voters passing a four-year, $360-a-year parcel tax in November.

If voters pass the ballot measure, the City Council has agreed to lay off no officers for three years.

However, if voters do not pass the parcel tax and a modification of a prior parcel tax also on the November ballot, the department would be left with roughly 574 officers. In December of 2008, the department had a record high of 837 officers, but now has 686 due to attrition and the layoffs of 80 officers on July 13.

"The police officers in this department are heroes every day," said the police union's president, Dom Arotzarena. "They've given their lives for this city. They've now given more."

Under the agreement, officers would pay 4 percent of their salaries toward their pensions starting in 2011. They would pay 7 percent in 2012 and the full 9 percent in 2013. Currently, all other city union workers pay at least 9 percent.

In addition, the police union accepted a later retirement for new hires. Officers now can retire at age 50 and earn 3 percent of their salary for every year served. Under the agreement, the retirement age would move to 55.

State pension rules do not allow the city to lift the retirement age for active employees, according to city staff.

The union vote did nothing to alleviate the concerns of Marleen Sacks, an Oakland resident who has twice sued the city over a prior police staffing parcel tax, Measure Y, that she believes the city misspent. With no minimum staffing requirement included in either of November's ballot measures, Sacks said she opposes them, too.

Oakland residents, she said, could pay more for officers but get less service because attrition erodes the department by about 60 officers a year.