Cavell Tarn overflowed Saturday morning, washing out the road immediately below the parking lot and indefinitely closing the Mount Edith Cavell day-use area to visitors.
According to Pam Clark, visitor experience manager for Jasper National Park, the incident was caused by a combination of factors, including hot, dry weather, high water levels and heavy rainfall the night before.
“There was an accumulation of melt water and then just preceding the event there was a heavy rain event, and a lot of rock and debris and mud and ice just fell from that.
“So there was nowhere else for the bathtub to flow,” she said, noting that the tarn, located at the foot of Mount Edith Cavell, always has high water in August, as was seen two years ago when Ghost Glacier fell from the side of the mountain.
Over the weekend, initial reports suggested the overflow was caused by falling ice from Angel Glacier, but according to Clark, there is no indication of that.
“This is very different from 2012 in that there weren’t any big chunks of ice deposited around the lake,” she said, referencing the scene after 70 per cent of Ghost Glacier fell into the tarn in the early morning hours of Aug. 10, 2012.
Rather, the Aug. 16 washout, left behind debris spanning from the tarn to the road—fortunately for Parks Canada, the water avoided all of the new infrastructure that has been placed in the last two years.
“There was no damage to any of the new facilities: the little easy trail or the benches or the picnic tables. The water didn’t come that close,” said Clark.
The highway crew has already cleared the road of debris, but it will remain closed indefinitely as Parks analyzes the scene and determines exactly what happened.
To do that, staff will consider the evidence on the ground, as well as time lapse photos.
That analysis will help Parks to determine when it’s safe to reopen the area to the public.
“Public safety is our primary concern,” said Clark, noting that she knows people are keen to explore the area, but until it’s safe to do so it won’t be open.
The road is, however, accessible from the junction of Highway 93A up to the Edith Cavell Hostel for those who have reservations for the hostel or with outfitters in the Tonquin Valley, as well as to hikers with backcountry permits for the Tonquin Valley.
The remainder of the road will remain closed.
Parks completed a risk assessment for the area following the fall of Ghost Glacier in 2012. Since then it has been working to implement the recommendations within the report, and according to Clark, the agency has gained a lot of ground.
That includes closing the Lower Path of the Glacier trail, discouraging people from going down to the tarn by building a platform and placing safety signage. The next step is to install new interpretive signage.
Nicole Veerman
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