Taking a cue from Berkeley's approach to controlling rowdy fraternity parties, Rohnert Park passed an ordinance Tuesday to crack down on noisy parties.

The unanimous City Council vote comes shortly after the start of the fall semester at Sonoma State University, whose students helped make Rohnert Park the No. 1 place in the county for raucous parties.

The ordinance allows for an initial warning, but provides for a $500 penalty if police have to show up twice within two months at the same address. Penalties escalate to $750 for a third response and $1,000 for a fourth complaint. Landlords also will be liable, unless they show diligence in evicting unmanageable tenants.

"We feel this is a fair approach that will also protect the community," Councilman Tim Smith said.

A few students spoke against the ordinance, saying it would spoil their fun. But council member Vickie Vidak-Martinez replied that "no one should have fun at someone else's expense. We're trying to make the city safe and comfortable for all to live in."

Rohnert Park police said they modeled the proposal on a 12-year-old ordinance in Berkeley, which is home to a large University of California campus. Berkeley's law also includes tiered fines for repeat offenders.

A student leader from Sonoma State praised Rohnert Park officials for meeting with students and university administrators last spring when the party ordinance was first discussed. The ordinance was delayed until the new academic year to allow students time to comment. It is expected to go into effect in about 45 days.

"I think it's a fair and equitable and reasonable ordinance that takes all of our concerns into account," said James J. Reilly III, legislative representative for the SSU Associated Students , the student government.

On a per capita basis, Rohnert Park is the rowdy party leader of Sonoma County. Last year, Rohnert Park police logged 772 party calls, or 18 calls per 1,000 residents. While Santa Rosa had more party complaints - 1,505 - it averaged only 10 calls per 1,000 residents because of its larger population.

Rohnert Park police said there has been a steady rise in the number of party calls over the past two years, and they increase as students start returning to school.

In August, September and October of 2004, party calls increased so significantly that they accounted for about 10 percent of the patrol workload from 9 p.m. to 7 a.m.

City officials said they weren't targeting Sonoma State students, and there are other spikes in party complaints during July and December when students aren't in school.

The existing city ordinance was considered inadequate because it only allowed police to bill for the cost of their response if officers had to show up twice for the same party on the same day.

The Department of Public Safety wanted to change the ordinance so they could bill residents who have two or more party calls over a six-month period.

Students said that could make it even tougher for them to find rental housing. Most students who attend Sonoma State live off campus. Slightly more than 1,000 live in Rohnert Park.

Instead of the twice in six months threshold, the council opted to penalize offenders who have more than one loud party over a two-month period.

Police said they want to target the perennial party houses, the ones that generate repeat complaints. In most cases involving noisy parties, police do not have to return to the same address. But about 45 residences last year generated three or more police responses. And one house had nine police calls.