Some local environmentalists are fuming over a new Niagara conservation authority plan to build a zip line attraction on sensitive land in Binbrook.

The Niagara Peninsula Conservation Authority (NPCA) plans to build zip lines through a quiet, heavily treed area at Binbrook Conservation Area. On Tuesday, Hamilton city council's planning committee made that easier with a 4-3 vote to rezone it.

Conservation fans packed the gallery, saying the NPCA's mandate should be protecting nature, not putting zip lines near wetland.

The conservation area already has fishing, canoeing, a beach, a splash pad and other amenities, said Brett Harrington, chair of the volunteer-run Glanbrook conservation committee. This area is dedicated to hiking and species at risk.

"They've foregone their objectives to become a commercial enterprise," Harrington said.

Harrington likened the Binbrook plan to Thundering Waters, a planned NPCA-approved residential and entertainment development on 484 acres near Marineland.

The Binbrook land is home to 175 varieties of birds and migrating monarch butterflies, Harrington said. The Ministry of Natural Resources and Forestry also said there were several bat species at risk there, although the zip line plan will keep away from cavities they use to nest.

NPCA planners, meanwhile, say the authority has covered its bases.

The Binbrook attraction, called Treetop Trekking, will include a Treewalk Village and aerial courses, said Brynne O'Neill from GSP Group.

Aerial courses won't go across the wetlands, she said. There will also be a 15-metre buffer of vegetation around the wetland. Construction will happen outside breeding bird and bat season. In five years, the NPCA will also evaluate the project to make sure it isn't harming the environment.

Brenda Johnson, Ward 11 councillor, said the NPCA evaluating its own cash-generating project is a conflict of interest. She also thought people weren't informed enough. Harrington's group, for example, was never consulted.

The NPCA will also cut down 100 trees for the project. Thirty-one of those trees are dead or ailing. The rest are healthy. It will plant 100 new trees nearby.

City planning staff approved the project. So did councillors such as Terry Anderson, who is temporarily in the Ward 7 chair.

Zip line parks encourage people to get off the couch, he said, and kids to go outside.

"One of the problems we have as a society is we have so many kids sitting in front of the television with their video games," he said. Without a zip line park, "those birds will be there but no one will see them."

City council still has to ratify the rezoning Sept. 26. On Tuesday, though, Harrington sounded defeated.

"Obviously I'm disappointed," he said. "Conservation areas should be about conservation."

Jason Farr (Ward 2), Terry Anderson (7), Maria Pearson (10), Robert Pasuta (14)

Doug Conley (9), Brenda Johnson (11), Judi Partridge (15)