In 2005, Riverside police hit their high-water mark for arresting drunk drivers. Officers that year hauled in a whopping 140 people for driving drunk in Riverside, a number it hasn’t come close to since. In 2009, the number of DUI arrests in Riverside slid to 59.

But the downward trend in DUI arrests by Riverside officers appears to be over. In 2010, Riverside police made 77 DUI arrests and on April 5, Police Chief Thomas Weitzel released a report indicating that Riverside had made 40 DUI arrests during the first quarter of 2011 alone, putting the department on a pace for 160 this year. That would be the highest number of DUIs in Riverside since 2005.

According to Weitzel, the rise in the number of DUI arrests is no accident. At the beginning of 2011, Riverside police instituted permanent shifts for its officers. But Weitzel wanted a commitment in exchange.

“At the end of 2010, we had a department-wide meeting where we set priorities,” Weitzel said. “I felt I gave them the opportunity to go on permanent shifts. As chief, I wanted to receive something in return.”

What Weitzel wanted was aggressive DUI enforcement from his midnight shift. Of the 40 DUIs made by Riverside police during the first three months of the year, 36 of those were made by the midnight shift. Officer Brian Greenenwald, hired by the department in 2008, has been by far the most aggressive in making those arrests, sometimes making two per night.

Greenenwald made 33 of the 77 DUI arrests the department logged in 2010, three times as many as the next highest officer.

“He’s aggressive and it’s very contagious,” Weitzel said.

Weitzel said the drop-off in DUI arrests from 2006-2010 reflected a few factors, including a manpower shortage that resulted in officers pulling more overtime shifts.

“They were getting burned out and needed to be refocused,” Weitzel said. “Last year we had over 450 bookings where we held someone in custody. That was up significantly from [395 bookings in] 2009. If the first three months of 2011 are an indication, we’ll surpass that.”

Another reason for fewer DUIs was a shift in priorities from the borders of the village to inside Riverside.

“Traffic enforcement has been the wish of the residents,” Weitzel said.

Police have responded to that wish during the day by more aggressive enforcement in school zones. But at night, there’s little in the way of traffic or parking enforcement to be done, Weitzel said.

That may be reflected in the fact that Riverside police issued 341 fewer parking tickets in 2010 compared to 2009. The number of parking tickets issued by Riverside police has plummeted since 2007 when nearly 3,400 were written. In 2010, police wrote 1,947 parking tickets.

“There aren’t that many parking violations in Riverside anymore,” Weitzel said. “There’s not this great demand for us to be out there issuing citations for illegal parkers in the central business district.”

As far as getting back to 2005-era DUI figures in Riverside, time will tell. A strong first quarter doesn’t necessarily mean a blockbuster total by the end of the year. In January 2008 alone, Riverside police made 35 DUI arrests. That turned out to be 40 percent of the 87 DUI arrests made by Riverside police during all of 2008.