NORTHWEST TERRITORIES
Frank T'Seleie Sr. has watched the Mackenzie River transform since he was a young boy living near Fort Good Hope.

Ice on the Mackenzie River at Fort Simpson this spring. Water levels dropped to some of the lowest levels in more than 30 years this summer and hydrologists blame lack of precipitation not just in the Northwest Territories, but along the entire system that feeds the river. - NNSL file photo

"I noticed when we were kids, we had certain swimming spots that no longer have water in those areas," said the community's vice-chief. "Over the past, I'd say 30, 40 years, it has changed considerably, the river. Particularly this year."

Water levels dropped to some of the lowest levels in more than 30 years this summer and hydrologists blame lack of precipitation not just in the Northwest Territories, but along the entire system that feeds the river.

"The whole Mackenzie system is affected by a very large area in the southern Yukon, northern B.C. and also northern Alberta," said Roger Pilling, hydrometric supervisor with Water Survey of Canada, based in Fort Simpson. "All those areas have been fairly dry so that's the biggest factor."

The water level at Fort Simpson is typically about five metres, but had fallen to 4.4 metres by the beginning of October, Pilling said. The record low was observed in 1981 when water levels fell to 4.2 metres.

The Peace and Athabasca Rivers feed Great Slave Lake, which drains into the Mackenzie River. Lack of precipitation in B.C. and Alberta resulted in low water levels in those rivers as well, Christine Roger, a media relations worker with Environment Canada, stated in an email to NWT News/North.

"The rivers and lakes in this system are all connected, so the low levels in the Peace - Athabasca system translate into low water levels in Great Slave Lake - the source of the Mackenzie River," Roger stated in the email.

Levels in Great Slave Lake dropped throughout the summer to about 25 cm below average by October, according to Environment Canada.

Roger stated that water levels in the Liard River, which joins the Mackenzie River at Fort Simpson, were also low this summer.

"The Liard flows from southeast Yukon and northeast B.C. and was near record lows from late July until early October," she added in the email.

It isn't just a lack of rainfall this year that's responsible, Roger added. The summer of 2013 was dry in B.C., Alberta and Saskatchewan and snowfall that winter was average to below average in the Peace-Athabasca watershed.

Conditions were similar in the Northwest Territories, Pilling said.

"We had a fairly dry winter last year and then followed by a dry summer, so it's kind of a long, drawn-out thing," he said. "It's below normal precipitation for this summer and even last winter the precipitation was at or below normal in pretty well the whole Mackenzie River basin."

Snowfall this winter is one of the factors that will determine the river's fate next year, Pilling added.

"The big thing is that we've had below normal precipitation and, unless we get above normal precipitation this winter, it's likely going to be low possibly even in the future," he said. "Great Slave Lake is such a big factor in the flow on the Mackenzie River, so unless we get significant precipitation over the next period, even all this winter, the water levels are likely to remain low."

David Campbell, head of B.C.'s River Forecast Centre, said the province's hydrologists are watching to determine whether the dry spells signal a larger trend.

"We've certainly seen that in the Peace region in B.C. We've had several fairly low flow years in the last five years," he said. "It seems that it has been more common the last few years. I don't think we've got anything definitive to say, but it's certainly something we're keeping tabs on, whether or not there are longer term trends going on."

The human impact

T'Seleie Sr. said he worries about the impact the W.A.C Bennett Dam in B.C. is having on the Mackenzie River.

The dam regulates the flow of the Peace River. In an email to NWT News/North, Mora Scott, media relations officer with B.C. Hydro, said both the W.A.C Bennett and Peace Canyon dams have a "very small impact" on flows into the Mackenzie River.

But T'Seleie Sr. said he is also concerned about warming temperatures increasing the amount of landslides along the river, which builds up silt in the riverbed.

"The silt in the water, that's frost thawing out along the river and then it washes down during the rainstorms," he said. "All that silt collects down here."

Low water levels forced Northern Transportation Company Ltd. to cancel barge service for the year as of mid-September. T'Seleie Sr. said if there is a trend and water levels continue to stay low, residents who depend on the river will be the hardest hit.

"Barges have been cancelled and if it continues the way it is, we're in real trouble," he said. "We don't have road access other than the winter road, so it's going to affect the communities if it continues to go the way it is."