Mystic — Stonington First Selectman Rob Simmons and other proponents of the Mystic River Boathouse Park project urged support Saturday for the proposed town purchase of a 1.5-acre parcel of land on the Mystic River.

About 100 residents attended an open house at the Route 27 site tucked between Mystic Seaport and an ice cream stand.

Simmons said the parcel’s availability represents a “once-in-a-lifetime” opportunity to preserve public access to waterfront property, a key goal of the town’s 10-year Plan of Conservation and Development.

Plans call for turning the site into a public park.

Friends of Stonington Crew, a group that supports the high school’s crew program, which has outgrown its current location at the Seaport, would seek to develop a privately funded boathouse on the property.

“At some point, the town has to step up to the plate,” Simmons said.

In fact, it’s Stonington taxpayers who will decide whether the town commits to the $2.2 million purchase, either via a Sept. 20 town meeting vote or a subsequent referendum.

The Board of Finance voted unanimously last week to recommend that the town approve bonding for the purchase.

The Board of Selectmen will decide whether to adjourn the town meeting to a townwide vote.

So far, Simmons said, there has been no groundswell of support for a referendum, which would involve additional cost.

Mike O’Neill, director of rowing for the Stonington crew, said the town’s acquisition of the site would provide the high school crew program with a “permanent home” and boost efforts to promote public rowing.

Founded as a club sport 17 years ago, crew at Stonington High is now one of 11 such varsity programs in the state. With 90 boys and girls participating, it is the high school’s largest sport, O’Neill said.

Over the years, he said, more than 30 crew participants have won athletic scholarships — their total value exceeding the cost of the riverfront property.

Bill Fain, a Seaport Heights resident who attended the open house, was supportive of the proposed purchase.

“I’m feeling pretty good about it,” he said. “It’s a beautiful spot, and it would be a wonderful public good to make it available for everyone’s use.”

Fain, a real estate broker, said the development of a public park at the site would enhance nearby property values.

Two other Mystic residents, Carlas Pilo and Wendy Bradford, said they had questions about how the proposed park would impact traffic on Route 27, a much-traveled link to Interstate 95.

“You have to convince me that people will be able to get boats in and out of here,” Pilo said. “It seems like a lot for a small property.”

The town enlisted the Trust for Public Land, a nonprofit organization it has worked with the past, to negotiate with the owner of the 1.5 acres, Fred Baumgarten.

Fred Boling, the trust’s project manager, said the trust has secured an option on the property and would deliver the deed for it to the town if residents approve the purchase.

b.hallenbeck@theday.com