The rains started to fall about five days ago in southern Alberta, according to meteorologists. The rains were significant. They quickly added up to eight inches in some places, experts said.
The still partially frozen landscape, not able to soak up this unprecedented deluge, flooded neighborhoods from Canmore to Calgary and beyond. It was this unique convergence of factors that played a role in this week’s flood devastation, experts said.
“To have these very large flood events … the stars have to line up,” Uldis Silins, a hydrologist at the University of Alberta in Edmonton said.
“In this particular case, it was a little bit of precipitation preceding the heaviest rainfall, and then a period of 16 hours of very heavy rainfall in the Elbow. In the Crow’s Nest Pass, it was about 12 hours of very heavy rainfall on top of already wet ground,” he added.
Referring to Alberta’s steep landscapes that played a role in the flooding, Silins said, “And then in the case of the Elbow, that’s occurring in the headwaters of a very steep watershed, and so those flows then are routed down fairly quickly down valley. In the case of Calgary, they arrived fairly quickly.”
In addition to Alberta’s so called “unforgiving landscape” which forces waters to run down rapidly, another factor that contributed to the flooding, according to meteorologists, was the already soggy ground from previous rains.
Flood waters have killed at least three people and forced 75,000 to flee from their homes, reports say.
“The entire town has been evacuated,” Raziya Gulamhussein, a Calgary resident said. “I hope this is once in a century event.” She added that to have Calgary under water was alarming.
Bow and Elbow rivers were overflowing. Waters soaked homes and carried away bridges. They turned streets into dirty canals. Sources said two bodies were recovered from High River on Thursday.
“I grew up here, I’ve spent a lot of time on the Bow and Elbow Rivers,” Calgary Mayor Naheed Nenshi said. “And I have never seen the river that high or that fast. Particularly that fast. The Bow River when I saw it looked like you were looking at an ocean. I was there looking at that same bridge in 2005 and this is no comparison.”
The waters rose to the 10th row of Saddledom, the city’s hockey arena. Schools remained closed Friday amid road closures and transit interruption. The deluge forced the evacuation of the Calgary Zoo.
“This is reminiscent of Noah’s ark,” Gulamhussein said, referring to the Biblical narrative.
Calling the unprecedented level of flooding “stunning,” Canadian Prime Minister Stephen Harper said it was not clear if things would get worse. He noted that the weather had gotten better and the water seemed to have peaked. Harper said he was shocked at the magnitude of the flooding in Alberta.
“This is incredible. I’ve seen a little bit of flooding in Calgary before. I don’t think any of us have seen anything like this before. The magnitude is just extraordinary,” he said.
“We’re all very concerned that if gets much more than this it could have real impact on infrastructure and other services longer term, so we’re hoping things will subside a bit.”
Mayor Nenshi said Saturday, the high water levels had not declined. Many neighborhoods in Calgary remained under water.
“We’ve sat at the same level for many, many hours now,” Nenshi said. “There is one scenario that would it go even higher than this, so you’ll either see the Bow river continue at this level for many hours or you will see it grow even higher and we’re prepared for that eventuality.”
Calgary’s unique terrain has helped put the city under water. Unexpected weather, and the still frozen landscape have assisted in creating miserable conditions.
By Perviz Walji