A group of men drinking beer on a front porch a couple of weekends ago shut off their music just as police approached.

A neighbor had called about the sounds pumping from the East Washington Street residence just after midnight.

Officer Niles Mercer, leaving his patrol car to join them on the porch, asked the men to take the party inside.

“If I have to come back, I’ll give you a disorderly house,” he said.

But it wasn’t necessary. By the time he was back at his car in no more than 10 minutes — the routine length of such a visit —the last of the men was already indoors.

“I’m happy,” he said, smiling. “They’re happy.”

That night, April 10, Iowa City police responded to 12 noise complaints. And over the course of that weekend, from April 8 to April 10, they wrote six citations for disorderly house.

With an ordinance on the horizon that will ban anyone under 21 from being in a bar after 10 p.m., many in the community have been eyeing that number, with some members speculating it may jump. Officers, such as Mercer, aren’t so sure — but say they have a plan, just in case.

First, they’ll wait to see if anything changes.

If the party moves from the Pedestrian Mall into neighborhoods, Iowa City Police Chief Sam Hargadine has said his department would increase neighborhood patrols and use grant funding to supplement patrol watches with officers specifically assigned to address house parties, according to a March 17 memo to Iowa City city councilors.

University of Iowa police will also return to patrol the Pedestrian Mall — as they did last year — as temperatures climb to help address issues of violence. Such a move frees Iowa City officers to move into neighborhoods, if the need arises, said Charles Green, the assistant vice president for UI police.

Still, Iowa City police aren’t planning to make staffing changes until they see exactly what effect the ordinance will have after it’s implemented on June 1, said Iowa City police Lt. Mike Brotherton, who is in charge of the late-night shift.

“Some people thought that when we went 19, it would cut down on the issues downtown, but you still see 18-year-olds,” he said. “The question is, how many people will still be downtown when they are 18, 19, or 20?”

The answer remains to be seen, as does whether house parties will multiply.

UI experts weighed in their thoughts for the latter question in an April 16 guest opinion in The Daily Iowan, saying the number of house parties likely won’t increase, especially not to an extent that would counter the reduction of drinking downtown.

Peter Nathan, a former UI provost and alcohol expert, and Anne Helene Skinstad, a UI associate professor of community and behavioral health, wrote: “Seeking, finding, then attending a house party is much more difficult than walking to the Pedestrian Mall and entering a bar. For this reason, access to alcohol by UI students will be substantially diminished.”

A study funded by the National Institutes of Health found that on college campuses where police directed more officers to “party patrols” and cracked down on drunk driving, drinking wasn’t displaced. Instead, the students started self-policing, and the number of alcohol-related issues decreased, according to the 2009 study by Bob Saltz of the Pacific Institute for Research and Education. The nonprofit organization focuses on problems associated with alcohol and drug use.

In Iowa City, officials wait to see what’s next.

The market for fake IDs may flourish, Brotherton speculated. Or perhaps, the officer continued, a savvy business owner may open an alcohol-free establishment for those under 21.

He said he knows for certain, though, that college students won’t stop gathering on weekend nights.

So does Mercer. The officer of two years, who regularly patrols both neighborhoods and downtown between 11 p.m. and 7 a.m., said dealing with house parties and downtown is different, but neither one is any more difficult than the other.

Driving his car along Gilbert Street around bars’ closing time, he said, “People do foolish things downtown, and they do foolish things at house parties.”