CALAIS, Maine — City officials set the 2010 mill rate this week, dropping it from $24.70 per $1,000 valuation to $23.40 per $1000.

City Manager Diane Barnes, however, warned that a restructuring of property valuations could mean homeowners may not see a reduction in their tax bills.

Calais Tax Assessor Lorna Thompson explained that a 20 percent across-the-board increase was programmed into the software that calculates property assessments, and then each property was depreciated from there.

She said the impact for each property would be different based on age, size and condition.

Thompson said the state of Maine asks all towns to assess at 100 percent, but penalties can be levied if assessments drop below 70 percent. That percentage is accomplished by comparing the selling price of a property to its valuation.

Thompson said Calais was at 88 percent of sales in 2009, and this year the ratio was 85 percent.

She said adjusting the cost schedule software is an annual move in some communities. In Calais, sales amounts have been outpacing the city’s assessments, Thompson said.

“It is a buyer’s market right now, but the turnaround in sales is much longer,” she said. “However, Calais property sales seem to be chugging right along. We’re not really seeing it as bad as you see on the nightly TV news. Our sales seems to be doing fine.”

Barnes explained that the City Council’s goal was to cut the tax rate by 1 mill in order to lessen the impact of the new assessments and the loss of $170,000 in state revenue.

Many cuts were made, she said, including eliminating local dispatch, several positions and services.

“We also had to make up for a loss of $75,000 in excise taxes,” she said, and residents will feel the impact of the Legislature’s reduced homestead exemption. Barnes said the exemption changes this year from $13,000 to $10,000, which equates to a tax increase of about $70.