A river once poured into an icy Yukon lake. Now it’s just a trickle
Everything changed with the Kaskawulsh Glacier’s dramatic retreat
Along this stretch of Alaska Highway, where it curves between the southern edge of Lhù’ààn Män lake and the rugged peaks of the southwest Yukon, the dust storms can blow so thick that drivers have been forced to pull over. Where the two- lane road crosses the A’ay Chù river, sand drifts across the pavement as if it were snow.
Past the yellow motel in Destruction Bay and down a rutted gravel road, the small bay that once served as a place of respite for migrating birds has shrunk, exposing more parched land.
In Burwash Landing, worn wooden docks are stranded on a mudflat, out of reach of the water that used to lap at their sides. And in the coldest months, springs that once gurgled far below the surface of the lake have created new soft spots in the ice that make winter travel more dangerous.
Climate change has gripped the North. In a dramatic display of its power, a receding glacier stole the river that feeds this lake.
The consequences have rippled throughout the watershed. Now Kluane First Nation is being forced to adapt.
Deep in the St. Elias Mountains, the toe of the Kaskawulsh glacier was pushed up against a rock hill. For more than a century its meltwater had fed two glacial lakes that spilled over into two different rivers.
Most of that fresh water flowed north into A’ay Chù — the Southern Tutchone name for the Slims River. A’ay Chù is the major water source for Lhù’ààn Män or Kluane Lake. Water from this lake, in turn, feeds the Kluane River, and eventually flows into the Yukon River for its final journey to the Bering Sea.
Everything changed over the course of just a few days in May 2016. It took more than a century of fossil fuel combustion to make it happen. As the climate warmed — average annual temperatures increased by 2.3 degrees across northern Canada between 1948 and 2016 — the Kaskawulsh glacier receded. Eventually it pulled back just enough from the rock hill that a narrow channel opened through the ice between the two glacial lakes and gravity did the rest.
The higher lake drained into the lower, directing the entire meltwater flow first east to the Kaskawulsh River, and eventually south toward the Pacific Ocean.
A’ay Chù is now a shadow of the river it once was. Its typical inflow to the lake it feeds, Lhù’ààn Män, dropped from more than 350 cubic metres per second to 60 cubic metres per second in the month of July.
In turn, the lake’s summer peaks have dropped 1.6 metres and some experts say the lake could keep getting lower until eventually it stops feeding the Kluane River, Lhù’ààn Män Tága, altogether.
Sam White stops hiking and turns to survey the land below. From Thechàl Dhâl — Sheep Mountain — he can see the braided channels the river carved through its silty bed winding north toward Lhù’ààn Män.
This is where A’ay Chù used to pour into the lake — a fan of brown, sediment-laden waters merging with a picturesque blue.
Today the river is a relative trickle, carrying only water from the mountain creeks that feed into the valley. The delta is mostly dry. And, when the katabatic, or gravity-driven, winds that carry cold air off the glacier gust through the valley, they blast sand from the riverbed.
On the windiest days, dust storms block the mountains from view, says White, a Kluane First Nation citizen, who runs the eco-tourism and fishing guide business Kluane Big Katch.
“The silt is not going into the lake, it’s coming into our air. The air quality here has really changed,” White says. “When you breathe it, it plugs up your nose.”
He leaves the trail and takes a more direct path up the rocky slope. There are Dall’s Sheep just ahead.
This is Kluane National Park and Reserve. It’s home to Canada’s tallest peaks and its largest icefield. A vast 22,000 square kilometres of breathtaking wilderness.
For Kluane First Nation, there is painful history to this park and the two-lane road that marks its northern boundary — both served to restrict access to food from the land.
Now, Lhù’ààn Män, the lake Kluane people came to rely heavily on for food, is in jeopardy. These traditional foods, food harvested from the land and water, are critical to the health of Kluane people, said KFN Chief Bob Dickson.
“We hunt the moose, caribou, sheep, and we eat a lot of the fish out of this lake,” he says.
The Kluane Game Sanctuary, a portion of which later became the national park, was established during the 1940s in an effort to curb over-hunting by the army. It was the middle of the Second World War and troops had arrived to build the Alaska Highway.
Kluane First Nation people were banned along with everyone else from hunting and trapping in the sanctuary, and later the park — barred from lands that had supported them for centuries.
They were forced to settle in Burwash Landing, a lakeshore trading post just off the highway. First Nations had traditionally used this area as a summer camp.
It was decades before KFN people were allowed to harvest food within the park’s boundaries again. Though Parks Canada has made considerable efforts to build trust, some Kluane people, haunted by the fear of arrest, never returned.
Chief Dickson says some elders, “even though they have the right to hunt, they’re still scared to hunt (in the park).”
Today, Kluane First Nation, which has 241 citizens, is a selfgoverning First Nation with a constitutionally protected land claim agreement. The KFN government is based in Burwash Landing, where about 95 people live full time.
“People got used to this lake; we use it for foods,” Chief Dickson says.
He’s standing on the shores of the Lhù’ààn Män, looking out at the choppy waters, past the mudflats where the wooden dock is languishing and unused.
“We’re feeling this first hand,” he says. “Look at what’s happening with the lake, with our climate here.”
“Barring a renewed advance of the glacier, which is unlikely in our warming climate, the beheading of Slims River is permanent,” Dan Shugar and John Clague wrote in an essay for the Alpine Club of Canada’s 2018 State of the Mountains Report. The amateur mountaineering association has published three State of the Mountains reports since 2011 to share information about changes underway in alpine environments.
In 2017, Shugar, a geomorphologist at the University of Calgary, Clague, an environmental earth scientist at Simon Fraser University, and a team of other scientists from Canada and the U.S. published a study in the journal Nature Geoscience about the “river piracy” that cut the glacial flow of water to A’ay Chù.
The retreat of the Kaskawulsh Glacier, which began slowly in the1800s, sped up in the second half of the 1900s due to humancaused climate change. Between 1956 and 2007, it retreated 655 metres, according to the Nature Geoscience paper. Shugar and Clague found there was only a 0.5 per cent chance that the glacier retreat over the past century could have been caused by anything other than human-caused climate change.
Glaciers retreat when the mass lost to melt, called ablation, is greater than the mass gained through annual snowfall, or accumulation.
The Kaskawulsh behaves like the vast majority of glaciers around the world; as the climate warms, its toe, or terminus, retreats. The glaciers nearby are different.
The Lowell, Dusty, and Donjek glaciers beside the Kaskawulsh are surge glaciers — meaning they periodically advance very quickly. This typically happens after an extended period when ice and snow build up at the highest point of the glacier. Eventually, so much weight builds at this high point that the glacier must rebalance and the ice surges forward.
“We normally interpret the retreat of glaciers as the glacier melting away because of climate change, but you can’t interpret surge glaciers in the same way,” said Luke Copland, who holds the University of Ottawa’s research chair in glaciology.
Christine Dow, the Canada Research Chair in glacier hydrology and ice dynamics at the University of Waterloo, plans to drill into the three glaciers in the St. Elias icefields — the Lowell, Donjek and Kaskawulsh — using heated pressurized water and monitor them from the inside.
The idea is to find out what’s happening underneath these glaciers, how and why they move when they do, and how climate change is affecting these dynamics.
Meanwhile, as regular glaciers continue their retreat, more rivers are at risk.
“There are numerous locations in the mountains of northwest North America where drainage will be perturbed, and possibly re-routed, as glaciers continue to retreat. Lakes that are currently dammed by glacier ice will disappear and the meltwater that feeds them will take different routes,” Shugar and Clague wrote in the State of the Mountains report.
Canada has more glacier area than any other country, aside from Antarctica and Greenland. While most of this glacier coverage is found in the Arctic, where rapid melting is contributing to sea level rise, the mountain glaciers in B.C., Alberta, the Yukon, and the Northwest Territories are critically important sources of freshwater that support fish, wildlife and communities.
These glaciers in the Western Cordillera mountain region, which covers the Yukon, B.C. and parts of Alberta and the N.W.T., are projected to lose between 74 per cent and 96 per cent of their volume by the end of the century, according to the federal government’s recent climate change report, and it could spell trouble for fresh water supplies and hydro-electricity generation.
Already, “climate warming, combined with periods of reduced precipitation in western Canada, has contributed to total thinning of glaciers in the southern Cordillera by 30 to 50 metres since the early 1980s,” the federal climate report said.
In the Yukon, glaciers and icefields shrank by 22 per cent between1957 and 2007, the report said.
Right now, rapidly melting glaciers are sending more meltwater into rivers and lakes in the western Cordillera region than they would be without climate change, according to John Pomeroy, the Canada Research Chair in water resources and climate change at the University of Saskatchewan.
“It’s sort of like spending out your savings account to supplement your chequing account, but eventually your savings account runs out,” he said.
“The world is trying to avoid warming up by 1.5 degrees and there’s global consensus that going beyond that would be disastrous. Northwestern Canada, the Yukon and the high mountains through the Cordillera have already warmed up much more than 1.5 degrees,” Pomeroy said.
“We are seeing a catastrophe in these areas through the loss of snow and ice.”
The precise impact the glacier loss has on a particular watershed depends on how climate change unfolds. In some areas, more precipitation is expected, which could mean more spring snowmelt to help offset the loss of seasonal glacial meltwater.
“The part that worries me the most is when we get severe drought years,” Pomeroy said.
In those years, the glaciers are a safety net.
“Without the glaciers or with greatly reduced glaciers, we won’t have that, and a dry summer will be a dry summer for river flow as well.”
Melt from glaciers in northern B.C. contributes about 30 per cent of the water that flows through the Whitehorse generating station, according to Andrew Hall, the CEO of Yukon Energy.
It’s the only one of the Yukon’s three hydro generating stations that relies even partially on glacier meltwater, he said.
This year, the Whitehorse area experienced one of the driest springs of the past two decades, and glacier melt has helped buffer the impact on hydro generation.
While Whitehorse is expected to get more precipitation as the climate changes, the region is also going to see more extremes, which could mean more frequent drought, Hall said.
For at least the next 50 years, Yukon Energy expects the inflow of glacial meltwater will continue feeding the Whitehorse hydro plant, Hall said, which should help offset the impact of severe droughts over the next few decades.
Kluane First Nation wasn’t afforded so much time to prepare for the consequences of the Kaskawulsh Glacier’s dramatic retreat.
For the last three years it was a struggle to get boats into Lhù’ààn Män. The Yukon government marina in Destruction Bay, about 15 kilometres south of Burwash on the highway, sat empty, its floating dock set aside. The water was so shallow, boats couldn’t be launched.
Sam White, whose business depends on getting his boat in the water, knew of a few other options, but none of them was easy. Trucks kept getting stuck.
“We were breaking all sorts of stuff,” he says. And “pulling each other out with chains.”
For those who manage to get out on the water, there are other changes to contend with.
In the western, shallow arm of the lake — officially the Brooks Arm, but known locally as the “Little Arm” — the weeds, which can now more easily reach the sunlight, are taking over.
“Try to drive through there with your boat, you’re constantly cleaning weeds off your prop and if it goes into your circulation you blow your motor,” White says. “A lot of people just avoid it.”
The shallow water in the Little Arm has made it more difficult for Kluane people to access cabins used for hunting, trapping and other traditional activities.
Boat access to prime moose hunting along the back channels and creeks off Lhù’ààn Män Tága, the Kluane River, has also been lost.
“It eliminates a lot of our traditional territory,” Chief Dickson says. “You’re stuck on one single thread, one pathway right down the middle of the valley. You can’t run off into all these little tributaries. I’ve been down the river and got stuck on a big rock because it’s so low.”
New challenges arrive with the cold weather. Freeze-up is not only happening later in the year, the ice is less predictable.
“Local people used to have a mind map of the lake and where to avoid,” says Pauly Sias, a KFN citizen and the executive director of the Dän Keyi Renewable Resources Council, a local resource management advisory body. “You no longer know where the soft spots are.”
Many of these “soft spots” in the ice are caused by natural springs bubbling up through the lake — moving water takes longer to freeze. These springs were always a concern, but Kluane people knew where they were and knew never to trust the ice above them.
As the lake level dropped, springs that were once far below the surface suddenly created new hazards.
Elder Dennis Dickson has a trapline northeast of Burwash, across the lake. He doesn’t trap too much anymore, but when he does, he’s mostly after marten.
On a good trail that’s already
cleared, it takes four or five hours by snowmachine to reach his first cabin and the first part of his journey is across a frozen Lhù’ààn Män.
Dickson says the ice is changing. “This year never froze ’til after Christmas on the far end (of the lake).
“The Little Arm — the Brooks Arm — there’s lots of streams underneath, you’ll be going along, you’ve got to watch in the wintertime. Always stay close to shore, if you ever go down the middle, you’ve got to watch. It could be -30, -35, it’ll be wide open,” Dickson says.
It wasn’t like that before “because it was deeper.”
The ice near the lake’s outflow to Kluane River, Lhù’ààn Män Tága, has also been compromised. Dickson almost lost a snowmachine there once. “The water is not deep, but it’s a nuisance,” he says, one that’s forced him to choose a new route across the lake.
Wildlife have changed their routines as well.
South of Burwash Landing, Sharon Kabanak stands on a parched piece of land.
“The ducks used to land here all the time. It was kind of like a duck sanctuary,” she says, “but it’s all dry now.”
Her grandchildren had to travel farther to hunt ducks this spring. “We used to crawl out here and the ducks would be sitting in the water right here,” she says.
White, whose cabin is nearby, says this small bay is about half the size it used to be. Some ducks still land here, but not as many, he agreed.
Some are questioning what all these changes mean for the fish, a critical food source for Kluane people.
With the major reduction of glacial meltwater, Lhù’ààn Män waters may warm, said Ellorie McKnight, who is working on a PhD in ecology and has been monitoring the lake’s thermaldynamics, or temperature, since 2015. “Kluane is still a cold-water system,” she said, but any warming could affect fish habitat.
If the lake gets warmer, lake trout — a key food source for KFN and a fish that thrives in cold water — could be largely confined to deeper waters, said Heidi Swanson, a professor and fish ecologist at the University of Waterloo.
The good news is that Lhù’ààn Män is quite deep and its churning waves, driven by the winds, bring deeper, colder water to the surface which should help preserve more of the lake trout’s habitat.
Also a concern is the spawning habitat. Fish tend to spawn in shallow areas, preferring to lay eggs on gravel bars. If the water level has dropped so that these spawning areas are now dry, those habitats have been lost.
Spawning areas that are still underwater, but shallower, could be too warm for the eggs, Swanson said.
Fish in these northern lakes tend to adapt quickly to change, she said, “but it all depends on what other habitat is available.”
Some salmon spawning habitat has been lost downstream in Lhù’ààn Män Tága, the Kluane River, according to Fisheries and Oceans Canada. The first Chum salmon to hatch since the big change in 2016 will return as adults next year and the federal department said it will monitor to see if the loss of spawning habitat has impacted salmon numbers. Environment and Climate Change Canada has conducted thermal imaging of the shoreline around Lhù’ààn Män and that data should help determine how much spawning habitat remains available in the lake.
“That being said, folks often tell us that when the water is warmer, the flesh is softer and there can be more parasites and so the quality of fish may change,” Swanson said.
“People don’t like soft flesh ... it doesn’t taste very good.”
For now, Chief Dickson says the “fish I eat are pretty good ... I had trout yesterday.”
Sam White, who spends considerable time on the water each summer, says there have been a few positives to the change in the lake.
It’s a lot more stable now. In the past, the water level could fluctuate by more than 1.5 metres between the winter lows and summer peaks, which were driven by glacier meltwater. People won’t have to adjust their docks with the seasons anymore, he says.
In some ways the fishing has improved, too.
Without the massive inflow of silt from A’ay Chù, the lake stays clearer, which is good for fishing. You can actually see the hook through the water, White says.
Much more of that silt gets into the air though, and that’s a major concern for the community.
Jill Bachelder, who recently completed her master’s in chemistry, monitored the dust at the mouth of A’ay Chù for three weeks last summer and found slightly elevated levels of arsenic, which she said occurs naturally in the groundwater and in the lake.
“It’s definitely a point of concern,” she said. “We’re not able to really say exactly how (if at all) that will impact the local wildlife and people in the area because we just didn’t sample long enough last year.”
This year, the research team, led by two professors at the University of Montreal, has stepped up its monitoring to better understand the potential health risks for people and animals.
Back in Burwash Landing, Chief Dickson is looking out at the lake, past the dock that’s sitting on dry land, and the deep tracks in the muck where people struggled to get their boats into the water over the last few years.
This is climate change. And, there’s more change to come, but the communities along the shore of Lhù’ààn Män are adjusting.
Earlier this spring, the Yukon government spent about $100,000 to dig out the bottom of the marina in Destruction Bay to let more water in. The community can use the boat launch again, and for the first time in a couple of years, the annual summer Kluane Lake Fishing Derby is back on.
Chief Dickson said Kluane First Nation is looking at building a new boat launch in Burwash as well, so KFN citizens don’t have to drive all the way to Destruction Bay.
But adapting to the changes is going to require more than infrastructure.
“We have to relearn our traditional knowledge all over again because things are changing,” Dickson says. And it’s not just the lower lake level. The winters are getting warmer, there’s more rain, and the moose rut — mating season — is happening later in the fall.
“We’ll live with it,” Dickson says. “When they created a national park they moved us here and we adapted to that. I think we’re going to adapt to this, just the same.”