CHICAGO – The Chicago City Council overwhelmingly voted Wednesday to decriminalize marijuana possession, joining a wave of states and big cities that have opted for fines instead of arrests for small amounts of the drug.

Starting Aug. 4, police can issue tickets of between $250 and $500 for someone caught with 15 grams or less of pot – the equivalent of about 25 cigarette-sized joints. Given that more than 18,000 people are arrested for pot possession in Chicago each year, the new law could generate millions of dollars for the city.

The push for pot tickets marks the latest in an increasingly long line of Mayor Rahm Emanuel’s maneuvers to find new sources of money that largely rely on penalizing people who run afoul of the law.

The mayor counted on bad behavior to balance his first budget, anticipating that the city would raise $26 million in increased fines for such offenses as failing to cut high weeds and not feeding parking meters.

This fall, cameras are expected to begin clocking motorists who speed on Chicago streets, resulting in tickets of up to $100 and tens of millions of dollars for the city. Emanuel framed that controversial plan as a way to leverage technology to better protect children near schools and parks.

Emanuel insisted Wednesday that the marijuana fines aren’t about the money. “It’s about what (police officers) were doing with their time,” he said. “The only revenue I’m interested in, I don’t want to be paying for these officers time and a half to sit in a courtroom.’