To cheers and near-thunderous applause, Bainbridge parks commissioners approved the final property purchase Thursday in the years-long effort to expand the Gazzam Lake Preserve.

Commissioners for the Bainbridge Island Metropolitan Park & Recreation District voted unanimously to buy 30 acres west of the lake.

The total purchase price was $831,837, but donations from Keep Gazzam Wild — the grassroots group that raised more than $200,000 to help prevent the land from being developed and a road punched through the preserve — will also be used to cover the costs.

The park district’s portion of the new 30-acre purchase is $620,000, plus a share of the closing costs.

The purchase follows last month’s purchase of the nearby Knudson property for $100,000.

“It’s nice to see something we’ve been working on for so many years move,” said Parks Commissioner Ken DeWitt.

Members of Keep Gazzam Wild were in the audience at Thursday’s meeting and rejoiced when the board approved the purchase. Adding the land to Gazzam Lake Preserve, which was created in 1995 and expanded in 2000, 2004 and 2005, will prevent the development of 15 new homes along the west side of the lake.

Commissioners also voted Thursday to make the purchase with a single payment, which will save $10,000 and additional interest.

The sale is expected to close on April 19.

“This was an amazing grass roots effort and shows the community’s commitment to keeping the Gazzam Lake Preserve intact as one of Bainbridge Island’s natural jewels,” said Karen Molinari, campaign coordinator for Keep Gazzam Wild. “Over 300 donors contributed to the project. We are forever grateful to the community for stepping up to this challenge.”

Commissioners also authorized parks staff to apply for funding assistance for the acquisition form the Washington Wildlife and Recreation Program.

Perry Barrett, a senior planner with the district, said the grant funds could be used retroactively on land acquisitions.