The Chief of Dettah, N.W.T., is concerned that an expansion project that may extend the Ekati diamond mine's life by a decade will have negative effects on caribou.
Technical sessions are being held for aboriginal organizations, government and others this week at the Tree of Peace Friendship Centre in Yellowknife as part of the project's environmental assessment.
Dominion Diamond Corporation wants to develop the Jay kimberlite pipe, which is located under Lac du Sauvage, about 25 kilometres southeast of the current Ekati mine.
The company needs to build a horseshoe-shaped dike with a surface area of four square kilometres around the pipe. The resulting open pit would be one of the largest at Ekati — about 370 metres deep.
The project includes building a new road that will be used to transport ore from the pit to the existing processing facility. Caribou crossings will be built into the road.
Dettah Chief Edward Sangris, who attended Tuesday's session on caribou, says he's worried about the Bathurst herd that migrates through the area in the spring and after calving.
"The caribou don't have navigational aid like the humans do; we cannot direct them to go here and there," said Sangris.
"No matter how many precautions they put into the traffic management consideration, it will always have an effect on caribou. In my view the footprint for development is getting bigger and the footprint for caribou is getting smaller."
Dominion Diamond says the Jay project should not have significant effects on migrating caribou. It says research shows migrating caribou generally avoid the current mine site.
In 2014, the company delayed development plans for a second pipe under Lac du Sauvage in order to reduce the mine expansion's footprint.
The company says it will temporarily shut down operations when large numbers of caribou are in the area.
It plans to release a draft of its traffic management plan by the end of the month.