Plans to redevelop the Ridgewood Reservoir site are on hold while state officials decide whether it should be designated a wetlands area.
The city Parks Department had been poised to unveil three potential redesigns for the site. But officials said that won't happen until the state Department of Environmental Conservation makes its decision.
"The DEC has received letters of concern about the Ridgewood Reservoir over the past couple of years, including a request to designate the area as a wetland," said DEC spokeswoman Maureen Wren.
"More information is being gathered to determine whether or not it meets criteria for state mapping as a wetland," she said.
The decommissioned reservoir, which straddles the Brooklyn-Queens border, is made up of three basins on 50 acres of land.
Nature has reclaimed the site and the basins are filled with various trees, mosses and wetland plants.
The city has been mulling plans to transform the area into a park and possibly place much-needed sports fields on the grounds.
But local residents and elected officials have been lobbying to keep the reservoir a wild nature preserve.
"The community has said all along that this is wetlands and it should be protected," said David Quintana, a local activist. "The money they are wasting on designs and other things should go toward renovating the fields that exist at Highland Park."
Parks officials said this week they are pushing ahead with plans to fix perimeter paths and lighting around the reservoir.
"We're working closely with the city Department of Environmental Protection and state Department of Environmental Conservation to investigate conditions on the site," the Parks Department said in a statement. "The environmental considerations at this site have been taken into account since the start of the project."