"We want to come up and say, `Before you sell it at the yard sale for $15, take a look at the true value of this gift you have,'" he said, surrounded by Canadian environmentalists.
Kennedy's target is a 9-meter-high dam a private company wants to build on the Magpie River, a 200-kilometre ribbon of wild water 900 kilometres northeast of Montreal. The company, Hydromega Services Inc., wants to generate 40 megawatts of electricity.
It says it would create as many as 150 short-term construction jobs and enough power to supply 40,000 homes and future industry in the economically impoverished north shore of the St. Lawrence River.
"We're eliminating nothing," countered Jacky Cerceau, the energy developer's president, who showed up at the news conference.
"We're only going to impact 150 meters of the river. White-water rafting is still possible."
Preserving the rafting, and turning the Magpie and its watershed into a national park, is the main reason Kennedy came to Quebec.
The dam, he said, would likely not cause species extinction or destroy major swaths of forests like some past Quebec mega-projects he's helped kill.
But Kennedy believes damming the river will kill a budding eco-tourist industry and rob future generations of one of the world's last unspoiled rivers.
"It's going to destroy that river as an economic resource for this industry, for white water," said Kennedy, president of the U.S.-based Waterkeeper Alliance.
Overnight, Kennedy's entry into the debate has transformed the Magpie River into a front-page political issue in Quebec.
It has already put Premier Jean Charest, who courted environmentalists in the election campaign, under pressure to follow the Parti Québécois' lead. The former PQ government scuttled plans for almost three dozen dams on rivers, leaving only the Magpie project and two others on the drawing board.