(UPDATED, Oct. 19, with a statement from Idaho Falls superintendent George Boland about the district’s bond-redemption and escrow accounts.)

IDAHO FALLS — A grassroots group is opposing the mammoth price tag on Idaho Falls’ school bond issue, and attacking the district’s ubiquitous claim that the measure won’t trigger a tax hike.

The group, dubbed “D91 Taxpayers,” launched a website and Facebook page last month to combat the district’s $110 million bond issue to fund upgrades to its two large high schools. The measure will go before voters Nov. 7 and require a two-thirds supermajority of votes to pass.

Group members say the big-money initiative to upgrade the schools is unnecessary, and a likely harbinger of future tax increases.

“Our patrons are our economic engine,” said Idaho Falls superintendent George Boland. “Why would we jeopardize their trust by lying?”

Despite at least one false statement made about the bond issue from the district’s spokeswoman earlier this week, Boland pointed out that Idaho Falls’ market value is surpassing early growth projections needed to keep a tax hike at bay.

Plus, he promises to dip into millions in the district’s reserve funds to cover added costs if the growth slows.

Will property taxes rise if the bond passes?

It’s hard to say, but one way to predict a bond issue’s long-term financial impact on taxpayers is to look at past market value growth.

Idaho Falls’ net taxable value has grown by almost a $1 billion since 2006 — good news for bond supporters, since a bigger tax base softens the blow bond issues and levies have on local taxpayers.

And the district’s market value continues to swell, with 2017’s annual growth already coming in at over 6 percent this year, according to Bonneville County numbers. The district’s most recent 20-year compound growth rate is 4.29 percent.

But growth since 2006 has been shaky at times. The district saw four consecutive years of decline from 2010 to 2013.

In a KIFI Local News 8 story published Wednesday, Idaho Falls School District spokeswoman Margaret Wimborne said the district would need “a couple of years of 5 percent growth, a couple of years of 2.5 percent growth and then a number of years at 0 percent growth.”

But financial experts at Piper Jaffray, the asset management firm in line to sell the project’s bonds, say the district will need to grow by a lot more than what Wimborne indicated if it wants to avoid an increase to its annual levy rate of $424 per $100,000 of taxable value. This growth includes 5 percent per year from 2019 to 2020 and 2.5 percent per year from 2021 to 2029. The bond issue’s remaining nine years, 2030 to 2039, would require no growth.

D91 Taxpayer spokeswoman Lisa Keller said unknown future growth renders the district’s claim of no tax increase misleading, at best.

“At worst, it’s unethical,” she said.

But Boland pointed to a other failsafes to curb a potential tax hike tied to the measure if the needed growth doesn’t pan out.

“Idaho Falls School District 91 has approximately $4 million available for bond payments in its bond-redemption and escrow accounts,” Boland said. “If necessary, the district could also access additional moneys from the general fund liquid balance.”

Is $110 million necessary?

Keller and other opposers say no.

They question the need for a new Idaho Falls High School, and say the district prematurely tabled plans to remodel both buildings.

“They had other options, but they shelved them for a $110 million bond,” she said. “Don’t get me wrong, we need something, but this is too much.”

Idaho Falls trustees originally explored ways to remodel both Idaho Falls and Skyline high schools, but ultimately settled on what Boland called the “biggest bang for the buck” — a remodel of Skyline and a complete rebuild of Idaho Falls at a new location.

But it’s not just a bigger bond issue that bothers Keller. Relocating Idaho Falls High would gut a historic part of Idaho Falls, she said.

“Property values will drop, even if they repurpose that school,” Keller said.

Boland argues that plans to rebuild Idaho Falls High anew stem from months of feedback gathered from patrons, not an executive decision on the district’s part.

“These are not my schools,” he said. “They belong to the patrons.”

Will the measure pass?

Again, it’s hard to say.

Keller is doubtful, arguing that the district could be starting high with the mammoth measure in order to eventually whittle it to a more realistic amount.

If the neighboring Bonneville School District’s experience with a similarly priced bond issue is any indicator, the measure is doomed — at least this time around.

Four years ago Bonneville trustees floated a $95 million bond measure to build both a new high school and a new middle school. The proposal failed to receive a majority of votes, let alone the supermajority a bond issue needs to pass in Idaho.

After failing a second and third time, the district whittled the measure to $63.5 million by ditching an original request for a new middle school. The measure passed in 2015. (Click here for a look at Bonneville’s strain on local taxpayers stemming growth.)

Boland expressed confidence in the measure, adding the public will decide on election day.

Keller said: “What’s the message we are sending out kids by amassing all this debt?”