The environmental impacts of what would be the Northwest Territories' fourth diamond mine are being studied in Yellowknife, the capital.
The Gahcho Kue project is a joint venture between De Beers Canada (51%) and Mountain Province Diamonds (49%). Twenty years of exploration has uncovered three mineable kimberlite deposits: 5034, Hearne and Tuzo.
But to get to the kimberlites, part of Kennady Lake, which sits on top of the deposits, would have to be drained. The lake is about 1% the size of Lac de Gras, the location of the Ekati and Diavik diamond mines, says De Beers Canada, the operator of the project.
A spokesperson for the company told CBC News the deposits would be open-pit mined rather than mined from the side, in order to access the kimberlites, which she described as "carrot-shaped":
“So to minimize the amount of waste we take out of the ground as we mine, it makes far more sense to do a circular motion around that carrot, if I can call it that, so that you can extract the carrot in pieces.”
De Beers Canada would re-route the lake, remove the fish, and refill it once mining is finished. The northeast basin of the lake would remain, separated from the lake by a small dyke.
De Beers Canada filed an environmental impact statement in December last year. A decision is expected by mid-2013.
Image of the Gahcho Kue project is by De Beers Canada.