Bainbridge parks supporters are hoping to turn a private jewel into a public gem.

Island voters will be asked during the Feb. 10 Special Election to approve a 20-year bond sale that would pay for the purchase of the Sakai property, 22.87 acres of largely undeveloped land that sits between Madison Avenue and Highway 305.

Supporters of the ballot measure say it’s a rare opportunity to get a truly unique piece of property for the public’s use.

“It’s all about creating a central recreational open space that’s in the middle of Winslow,” said Bruce Weiland, co-chairman of People for Parks, the pro-park campaign. “It’s the island’s heart and center.”

Weiland said although the Bainbridge parks district has parks across the island, there isn’t much in the Winslow area itself, where most of Bainbridge’s population calls home.

“This is literally the largest undeveloped parcel within the central core of Winslow,” Weiland said.

“This is the game. This is it,” he added, noting that if the property is not purchased for the public it will most likely be put up for private sale and jam-packed with homes. “This is not just another piece that we can add to the inventory. This is a once-in-a-lifetime chance.”

If the ballot measure is approved by voters, the Bainbridge Island Metropolitan Park & Recreation District will issue $5.9 million in bonds to pay for the Sakai property.

A supermajority vote is needed for the parks proposal to pass. The measure must get 60 percent approval from voters, and the turnout must be 40 percent of the 2014 General Election or more (which means at least 4,734 voters must cast ballots for the election to be validated).

The bonds would be repaid over 20 years by an excess property tax levy of approximately 8 cents per $1,000 of assessed value, or roughly $36 per year for the owner of a $450,000 home.

Supporters say the chance to create a central park on Bainbridge, however, is priceless.

“Thirty-six bucks a year is a bargain for this property,” said Jason Shutt, co-chairman of People for Parks.

The land includes 9 acres next to Madison Avenue, right across from the Bainbridge Aquatic Center and Ordway Elementary, land that could be actively used for recreation, he said.

“It’s not just more land that’s going to the raccoons and the deer,” Shutt said.

Although support has been widespread for the proposal — Shutt said folks he’s talked to have characterized the land purchase as a “no-brainer” — there has been some opposition.

Jean Capps, chairwoman of the Committee Against the Measure, said she thinks the property is overpriced and unneeded.

She said the county assessor values the Sakai property at $1.8 million.

“We’re paying a really high price; thousands per acre more than we should,” Capps said.

“My other concern is that we have 41 parks and 1,479 acres of parkland,” she added. “And they all require maintenance and improvements and so forth. There are costs there.”

Capps also noted that the property would come off the tax rolls if it’s purchased by the parks district, and that would increase the tax burden on islanders.

“We are one island and yet there’s five taxing agencies.

I feel like I’m being priced off this island,” she said.

Though supporters have touted the features of the property — it includes a 2.2-acre lake, the third largest on the island — Capps said the land is not as special as some have said.

It’s former farmland, she said, thick with brambles and alders.

“This is not what I would consider a beautiful park,” Capps said.

But Weiland said opponents of the measure are mistaken when they claim the property is overpriced, and he also noted that tax bills won’t rise if the proposal gets a “yes” vote at the ballot box.

“That is simply factually untrue that the price is too high,” he said.

The price was set by an independent appraisal, and the park district is legally prohibited from buying property that costs more than its fair market value.

Weiland pointed to the property Harrison Hospital obtained for its new medical center just north of the Sakai property on Madison Avenue, which was purchased for four times its assessed value.

“The bottom line is, assessed value is not a good indicator of real property values,” Weiland said.

Islanders also won’t see a net increase in their property tax bills, he added, because the new levy would be offset by the expiration of the 20-year bonds for Gazzam Lake and the Grand Forest that were paid off in 2014.

There’s no other large piece of undeveloped land that could be used for a park for Winslow, where most of the island’s population lives, he said.

“For people who like Manhattan, you try to imagine what Manhattan would be without Central Park. That’s the kind of lasting legacy we’re trying to create,” Weiland said.