He made the speech, which he called "Cherokee Unplugged," during the Board of Commissioners' meeting on Tuesday night.
In his outlook for 2010, he said property values in Cherokee "will be slipping in the 7- to 10-percent range," which would amount to a $5 million impact on the taxes collected for the general fund and fire fund combined.
Ahrens said the county government will be monitoring the situation over the next six months before the millage rate is set.
An increase in the millage rate, he said, "has to be considered."
The board is also looking at how service levels may be affected by the projected loss of revenue.
"You look at where you can afford to have a slight decrease in the level of service and where can't you afford to have a decrease," he said about measuring the service level.
Commissioner Harry Johnston said the county is taking every opportunity to "freeze" vacant positions in anticipation that the position may be cut in the 2011 budget. The county government, he added, is already operating lean.
"It is questionable that we can absorb a 7- to 10-percent reduction without drastic cuts that I don't think the people of the county want to see us make," Johnston said.
He added it would be "very difficult" to manage next year's budget without changing the millage rate.
County Manager Jerry Cooper said he, the board and the county staff will be reviewing "a number of things" to find ways to cut expenses and mitigate any impact on taxpayers.
"The board is committed to a low property tax," Cooper said about evaluating the millage rate.
The county's general millage rate, which stands at 4.381 mills, is the second lowest in the state behind Forsyth County.
During his address, Ahrens also talked about the county's efforts to identify properties to acquire for greenspace. Buying land for green space is one of the uses identified for the county's $90 million parks bond.
The board has also asked the state legislature to allow a one-cent tax for transportation, Ahrens said, which could generate $30 million a year for the county.
Ahrens in his address mentioned as well the county's effort to develop a marketing initiative to bring more companies to Cherokee.