That was the admission Friday by County Clerk/Auditor Steve Rawlings during a special County Commission meeting with Utah Tax Commission members and other state tax authorities.

"We're not certain the extent of the error, but the biggest factor seems to be in the Bountiful area," Rawlings said, attributing the problem to a change in computer programs.

That blooper, combined with the boom in the real-estate market since 2005 - plus recent county tax increases - combined to deliver sticker shock to thousands of south Davis taxpayers.

The combination resulted in a $5.7 million windfall for county coffers; Davis commissioners have devised a plan to return that windfall to property owners in November in the form of one-time tax relief.

County Assessor Jim Ivie described how his department switched from an old appraisal program to a new, streamlined system this year.

"We were having to merge the old with the new," Ivie explained.

In that process, appraisers made some data-entry errors, Ivie said, and Bountiful's new growth rate was set at 8 percent - as seen in other parts of the county - rather than the city's actual 4 percent.

Said Rawlings: "We got hard hit in the residential arena." He noted that some saw their tax bills double, or increase by more than $1,000.

By law, counties must reappraise all property every five years. One-fifth of the parcels get reappraised each year, with routine annual adjustments.

Davis officials hope to equalize the tax burden over the long-term by beefing up staff to allow reappraisals of all county properties each year.

On Friday, Rep. Paul Neuenschwander, speaking on behalf of his Bountiful and North Salt Lake constituents, said: "The citizenry there feels there has been a large windfall" - in terms of tax dollars flowing to county coffers. He expects tax reform to be a hot topic in the 2008 legislative session.

State officials met with Davis commissioners Friday out of concern the one-time abatement plan might not pass legal muster - or could establish a dangerous precedent for other legislative bodies.

However, Davis County Attorney Troy Rawlings expressed full confidence in the proposal, saying that state law gives commissioners the authority to address inequities.

"This is not only what we can do but what we should do," he said. "What we have here is an injustice and we're trying to correct that."

cmckitrick@sltrib.com

What's next

Monday is the deadline for property owners to file appeals at the Davis County assessor's office if they believe their assessed property values have been set too high.s

This appeal differs from Davis County's plan to offer one-time tax abatement in November, via line-item deductions on individual property-tax bills. To comply with state law, applications will be included with November's tax bills, which taxpayers must sign and mail back with their payments.

Here's how that one-time plan works: Property owners who saw their valuations rise more than the average 24 percent over the past two years can sign an application and get their tax bill trimmed by $100 for every $20,000 above that threshold.