Ypsilanti Township officials did a tally of registered single-family rental properties during September, when the total hit 1,997, or 13 percent of the residential units in the township.

That figure is up by more than 1,000 homes — or 109 percent — since 2008, which officials attribute to landlords snatching up the high number of foreclosed homes in the township. And those numbers only include single-family homes, not apartment buildings or complexes.

With the influx of renters has come a growing number of nuisance and criminal complaints at rental properties, and that has presented a new set of challenges for Washtenaw County Sheriff's Department deputies and township officials.

But a new strategy developed by deputies Lisa Farst and Erin Larkin seeks to provide police officials with an effective tool in addressing renter issues.

Each time a tenant is cited for any type of violation or arrested, a deputy fills out a form that is forwarded to the landlord or property owner by administrative officials. Lt. Jim Anuszkiewicz said that can include an arrest for a crime, an ordinance violation or a housing assistance violation.

The Sheriff’s Department over the past several months has been meeting with landlords whose tenants have regularly tied up police resources, and deputies are increasingly using the new tactic to curb issues caused by renters.

Those property owners police officials have met have usually said they aren’t aware of the issues their tenants are causing, Anuszkiewicz said.

“What we’ve heard in meeting with these landlords is they’re not always aware there’s a problem and the tenant doesn’t provide information that the police were out there.” he said. “After we meet with the landlords, communicate the problems and provide them with an action plan on how to move forward, it has mostly eliminated responses. That in turn helps out because we’re able to do a lot more things rather than responding to same location.

“This is an attempt to improve quality of life in neighborhoods in Ypsilanti Township and around the county.”

The Sheriff's Department and Ypsilanti Township are partnering on the effort, though it likely will be expanded countywide if it's successful.

Mike Radzik, director of the office of community standards, said the implications for the spike in renters for residential neighborhoods "are powerful." Rental homes make up 13 percent of the township's single-family housing stock, compared with 6 percent three years ago. If the upward trend continues at a rate of 15 percent over the next three years, then one of every five homes will be rented out by 2014, Radzik said.

Radzik said nuisance crimes and code violations are tougher to resolve at rental properties in part because police and ordinance officers usually only have contact with tenants and don't know who lives there or who is loitering.

Meetings with landlords and property managers have generally gone well, and they are mostly cooperative because the Sheriff's Department's success helps both parties, Anuszkiewicz said

“We’ve had an extremely positive response and are always looking for ways they can help us out and get rid of problems. Obviously, the more successful we are, then the more successful they are going to be.”

The Sheriff’s Department also is alerting aid agencies at the state and local levels when tenants who receive government housing assistance aren’t following the rules of their housing agreement through a local housing commission or HUD.

Anuszkiewicz said violations could include tenants housing unauthorized occupants, health and safety violations, tenants failing to cooperate with an investigation or tenants committing crimes. If a person is found to be violating their housing assistance agreement, then the department will contact the local housing agency providing assistance or housing vouchers.

That task has proven difficult, Anuszkiewicz said, because there are so many housing agencies from which people receive assistance. But he added that it is worth the effort and “a step in the right direction.”

Township officials also have been gathering data on how many people receiving housing assistance or vouchers live in the township, and they are concerned that there is a disproportionate amount compared with neighboring communities.

The township board authorized its attorney to gather data on the issue this year.

The West Willow neighborhood is one that has been most impacted by the spike in the township's rental properties. It was once largely filled with homeowners, but is estimated to hold more than 35 percent rental properties in 2011.

The New West Willow Neighborhood Association has tried to reach out to landlords and renters to involve them in the community, but some landlords are unresponsive or even jailed, NWWNA President Angela Barbash said.

Barbash said she was unaware of the Sheriff Department’s new efforts, but is optimistic the new measures combined with the neighborhood association's and the township's approach will help address some of the issues in West Willow.

Anuszkiewicz said he also is optimistic.

"We have seen some pretty good results, which is due to responsible apartment complex managers and landlords telling their tenants they are no longer going to be welcome unless they straighten up," he said.