Visitors to the Nordegg area will notice a whole lot of ‘shoreline’ around the man-made Abraham Lake.
The water level is very low this spring, as noticed this week by Aurum Lodge owner Alan Ernst.
Since visitors are expected to flock to the area on the May long weekend, Ernst wants to remind area residents that driving vehicles onto the lake bed is not permitted.
Cars and trucks used to get stuck in the mud near the lake every year. This becomes a big concern once water levels start to rise again, said Ernst, since this can be as much as a foot or two daily during peak run-off.
When the lake is very low, as it is now, Ernst believes possible to see the old air strip and foundations of the ranger station at the mouth of the Cline River. These were abandoned after the dam and reservoir were put into operation in 1972 with the construction of the Big Horn Dam.
About 54 square kilometres of the Kootenay Plains were flooded 50 years ago to help with power generation in the province. At the time, no public consultation was needed, even though this impacted the Stoney Nakoda First Nation people, flooding their pastures, cabins, graves and trapping area.
The resulting lake was named after Silas Abraham, a Stoney Nakoda guide and hunter who lived on the Kootenay Plains and later on the Big Horn reserve from the 1870s to 1964.
The artificial water body is Alberta’s largest reservoir, located on the North Saskatchewan River.
Abraham Lake, best known for its peculiar ice bubbles in the wintertime (these are formed from methane gas released from decaying plants on the lake bed that become trapped in the ice) is usually 32 km long. But the water area has shrunk compared to the wide expanse of visible lake bed.
While the lake’s water levels fluctuate widely from season to season, a spokesperson from TransAlta, which operates the Big Horn Dam, was not available on Friday to explain why the lake level was dropped so much this spring.
Ernst suspects it was drained more than usual, following exceptionally high water levels in 2021, which required the activation of an emergency spillway for an extended period in summer.
A photo he took of the Cline River estuary, including the North Saskatchewan River and Elliot Peak, shows a lot of snow at higher elevations. If the weather abruptly warms and the area gets a lot of rain, the run-off in the upper North Saskatchewan will be significant, he added.
“With another hot summer predicted, accelerated ice melt may well again fill up the lake by mid-to-end of August.”
Although Alberta Environment does not regulate Abraham Lake water levels, it does control Dickson Dam and so evaluates snowpack and spring weather conditions.
Snowmelt above the Kootenay Plains “is two or three weeks ahead of schedule and is approximately 70 to 100 millimetres less than it was at this time last year, but remains within the normal range,” states an email from the provincial department.
Conditions at a higher elevation shows snowmelt just beginning. “It is about 60 millimetres higher than this time last year, which is above the average range.”
An Alberta Environment spokesperson said mountain runoff volumes for the Red Deer River at Dickson Dam are expected to be average. But “it’s important to remember that mountain snowmelt itself cannot cause a flood,” he stated, as much depends on the amount of spring rain or snow, its intensity and the soil moisture.
Due to a drier fall and winter, Gleniffer Reservoir water levels are now below average. But higher elevation snowmelt is expected to start filling the reservoir in late May and June, added the spokesperson.
Dickson Dam operators regulate Gleniffer Reservoir to find a balance between ensuring a year-round water supply and preventing the flooding of downstream communities. Water levels are adapted to balance these risks, taking various conditions, including precipitation, into consideration.