For some, a proposal for a $50 million upgrade to the Kootenai County Jail means an equal amount of property tax relief.

It shouldn’t be that way. Jail expansion should stand on its own merits. But it’s hard to ignore the property tax dividends that the county’s popular half-cent sales tax brings. County residents have twice supported using a local-option tax to pay for jail expansion, with 61 percent approval in 1996 and with nearly 70 percent approval in 2003 after the Idaho Supreme Court ruled the original tax unconstitutional and the Legislature fixed the problem.

Last November, county residents added an exclamation mark during an advisory vote when 75 percent supported expanding the local-option tax to cover purchases and projects other than jail expansion, the only activity it can be used for now.

Apparently, Kootenai County property owners have embraced the local-option tax, which shifts the cost of jail expansion off the unpopular property tax and onto the sales tax, paid to some extent by out-of-county visitors and tourists. The cost of the expansion causes sticker shock — $30 million in construction and $20 million in “soft costs” for design, financing and contingency funds. But no one can argue that the expansion isn’t needed. Nor that the property tax relief isn’t wanted. Despite concerns raised by Concerned Businesses of North Idaho, the option tax has worked well for Kootenai County. Voters should support it again.

The Nov. 8 vote requires two-thirds approval for passage.

Under the proposal, half of the money collected from the half-cent sales tax would be used to expand the jail and half for property tax relief. County officials are asking to expand the jail capacity from 325 prisoners to 632 as well as enlarge the kitchen, booking area and other jail infrastructure. Of the added housing space, 162 cells will be reserved to isolate an increasingly dangerous jail population. Even Concerned Businesses agrees the expansion is needed.

The business organization, however, has raised several valid questions in asking unsuccessfully for the commissioners to remove the jail measure from the November ballot. It’s concerned that there’s too much soft money in the local-option proposal, that the language of the ballot allows the county wiggle room to use excess money from the tax for other detention projects, and that there are no incentives to retire the debt earlier than the designated 10 years.

Concerned Businesses is also understandably bothered by the cost of future staffing at an expanded jail.

Colleen Allison, jail expansion spokeswoman, says excess money could be used to refurbish the temporary holding cells at the county courthouse. That’s acceptable. Beyond that, the commissioners should set a clear precedent for future commissions that the sales tax should end when the expansion is paid for.

Despite the questions raised by Concerned Businesses, the sales tax remains a better way than a property tax to pay for this necessary work.