Canada's US$7b dam tests the limits of state power

New York

RUGGED, remote and prized for its rare microclimate, the Peace River Valley in north-eastern British Columbia is an agricultural oasis in northern Canada. Alfalfa, watermelon and barley fields sprawl across a landscape flecked by caribou tracks and seasonal trappers' huts, which reflect the role that indigenous peoples have played in this fertile land for more than 10,000 years.

But little of this abundance will be around much longer.

Within a decade, water will flood a 51-mile (82km) stretch of the river, the result of a US$7 billion hydroelectric dam and power station, known as Site C. It will be one of the largest public infrastructure projects in Canadian history.

The project has prompted mounting opposition and legal challenges from industry experts, former government officials, local landowners, aboriginal communities and others who say Site C poses a risk to the environment and violates constitutionally protected …