The North Shore Land Alliance is close to buying a 28-acre Mill Neck residential property to convert to open space.
The Old Westbury-based organization offered $5.2 million to purchase the land, which was accepted on Dec. 18 by the Humes family, which has owned the property for decades.
President Lisa Ott said both parties have signed a contract and expect to close in January.
Large blocks of open space are limited on Long Island, and state officials say work needs to be done to protect the amounts left.
"It has been a conservation priority for the Land Alliance for many years because of its connectivity to preserved lands, geographic features such as streams, ponds and wetlands and a diversity of plants and animals," Ott said.
The Humes property is located within the New York State-designated Oyster Bay Special Groundwater Protection district and was named a critical bird habitat by the U.S. Fish and Wildlife Service, the alliance said.
The organization will begin community outreach to create a conservation plan once it owns the property. The Alliance has helped conserve 1,007 acres in Nassau and Suffolk counties since its inception in 2003, Ott said.
Preserving open space not only protects the environment on Long Island, but also stimulates the economy and tourism, can bolster private property values, and can reduce the cost of government services associated with residential development, according to the 2014 New York State Open Space Conservation Plan.
The plan is updated every four years by a committee consisting of representatives from several state agencies, including the Department of Environmental Conservation, local municipalities and nonprofit organizations.
"Preserving open space is important everywhere," said Robert Marsh, the DEC's natural resource supervisor. "It is particularly important on Long Island because of the level of development we have here . . . there is limited open space available."
Marsh said the DEC owns about 20,000 acres of open space on Long Island.
The Humes property is located adjacent to more than 100 acres of protected land, including the Shu Swamp Preserve and 15 acres of Nassau County-owned land purchased from the Humes family in 2008.
"These conserved areas and surrounding lands nurture the headwaters of a series of rivers, lakes and waterways that eventually reach the Oyster Bay National Wildlife Refuge and the Long Island Sound," Ott said.
Mill Neck Mayor Peter Quick said village officials are "thrilled that it's going to be preserved."
The organization is funding the offer with donations and loans.
County Executive Edward Mangano said in a statement that he commended the Alliance for its efforts.
"Acquisition of this environmentally sensitive property will help connect preserved lands, streams, ponds, wetlands and protect endangered plants and animals," Mangano said.