Cobb County property taxpayers are getting another reminder this spring of just how bad the local economy has been. Chief appraiser Phil Hogsed said Wednesday that his office, which tracks valuations for unincorporated Cobb, its six municipalities and both local school systems, is sending out about 160,000 notices of reductions in value to property owners.

"That's more than we've ever sent out," he said. "In the early 2000s, we sent about 100,000 per year, but of course, those were increases."

Yes, times have changed.

Such notices are a double-edged sword for property owners. On the one hand, they mean that the tax on the property will be less, which property owners obviously do not mind. But they also denote a corresponding drop in the property's value. And that's not just bad for the property owners, but for local tax digests - the total value of all taxable real and personal property and registered vehicles in a given jurisdiction.

Cobb's tax digest went down very slightly last year, $67.3 million, or .02 percent, to an overall value of about $30 billion. That was the first time the digest had dropped in more than two decades. And that hit was a pittance compared to what's ahead this year. The value of the digest is expected to drop by between 9 and 11 percent this year, according to Hogsed. A hit of that size - about $2.4 billion - will have major ramifications on local governments.

Last year Hogsed's office was widely criticized because of the public's perception that it was not giving proper weight to falling property values. Assessments invariably went up during good times and deserved to be rolled back during bad times, critics correctly said. But the county last year reduced assessments on only about 12 percent of Cobb's 230,000 homes, even though headlines were dominated by news about home foreclosures and real estate meltdowns. Hogsed said that low figure was the result of the county having taken a non-aggressive stance toward reassessments through the years.

This year is different. The county is rolling back the assessments on 69 percent of residential revaluations. The greatest number of such decreases is found in Austell - very hard hit by September's historic flooding - where 82 percent of assessments were rolled back. Marietta was close behind, with 78 percent receiving a lower revaluation, and the figure for unincorporated Cobb was 68 percent.

To its credit the state Legislature last year passed a law requiring tax appraisers to consider "distressed" sales when determining fair market value. Such sales are a small, but still significant fraction, of transactions in Cobb.

"We're still talking less than 2 percent, but it's enough to affect the market," Hogsed said. "We'd like to think that we've bottomed out and we're on the way back up. But I'm not sure that's true yet in commercial."

Cobb's real estate prices will eventually be on the way back up, no question. But until then, the county's appraisers are doing the right thing by taking market conditions into full consideration as they prepare property assessments. And keep in mind that the impact on next year's valuations - and tax digest - could be just as dramatic.