DAYTON — Changes to the way Montgomery County tallied the number of vacant and abandoned properties countywide has provided a more accurate picture of the extent of the problem, officials say.

An incomplete count in May 2010 listed 1,622 properties, according to the Montgomery County Auditor’s Office. The refined list, compiled in December, included more than 7,000 properties.

“As this problem of blight and abandonment bloomed, we realized we needed better data and we felt real estate records were a good place to start,” Auditor Karl Keith said. “The problem didn’t come up over night.”

Keith said properties on the refined list had to meet at least two of three criteria including: two or more years property tax delinquent, water is shut off or, an assessment levied for mowing or other service to remove a nuisance.

During the most recent count, the county determined 13,737 properties were at least two years delinquent on taxes; 28,490 had the water shut off and 17,851 had assessments. Of those, 7,077 met two criteria.

“I think that’s a real (accurate) number,” Keith said.

Dayton topped the list with 6,225 abandoned properties, followed by Trotwood with 348. The cities of Englewood and Oakwood along with Butler and Perry townships landed at the bottom of the list with one property each listed.

The county did not have complete data from jurisdictions on water shut-offs for the first count, Keith said.

“We had a lot of data, but not a lot of good data,” he said. “We knew we had a problem, because of all the foreclosures.”

Keith said the list will enable communities, as they work on long-range planning, to target areas where resources are needed to combat blight. The more accurate method of determining exactly where vacant houses are located also will be helpful to the auditor’s office in setting values in 2014, Keith said.

“Having 7,000 abandoned properties in the county is draining community resources and it hurts the value of other neighborhood properties,” Keith said.

There are about 250,000 total properties in Montgomery County.

Contact this reporter at (937) 225-2362 or josmith @DaytonDailyNews.com.