"It was a cross between 'The Poseidon Adventure' and 'Jurassic Park,'" said Jake Veasey, the zoo's director of animal care, conservation and research.
Veasey and other workers spent the weekend at the African Savannah exhibit juggling two challenges at once: moving shivering giraffes out of belly-deep water and securing an angry hippo that had escaped his holding area.
A glass window had to be broken for Veasey to get into a building to tend to the giraffes — skittish creatures that don't cope well with cold and stress.
The building was so full of murky, brown water that he had to don a wet suit and swim to the back of the building to get to the giraffe enclosure.
At that point, the hippos were still where they were supposed to be, but, just in case, a shipping container was placed over a window that the hippos could have swam through.
Water levels eventually rose high enough for the dangerous herbivores to swim over the tops of their enclosure. Now they were able to move freely about the African Savannah building.
"There was the potential for the hippos to swim out of this building into a flooded zoo and potentially into the Bow River and we could have had hippos God knows where," said Veasey.
"They could have been 20 or 30 miles downstream."
Veasey said the powerful beasts could have easily pushed through the glass front doors, so cinder blocks and construction equipment were put there to block their way.
One of the two hippos, an older female named Sparky, stayed put. But a younger male named Lobi was much more adventurous.
"He was having a whale of a time just exploring a much bigger hippo pool than he was used to."
Lobi stayed at the front of the building for a while, while Veasey and his colleagues were around the back, trying to coax nervous giraffes out of the building and to dry land through an unfamiliar exit.
The zookeepers had to live with the possibility that Lobi could come closer. They had a high-calibre rifle handy just in case.
"They certainly kill more people in Africa than lions ever do. They're arguably the most dangerous African vertebrate," said Veasey, who could only tell where the hippo was by the rustling of debris.
At one point, Lobi managed to squeeze through a narrow door into a corridor and found himself stuck — and furious.
"It's a human being door that you could never comprehend a hippo could go through."
He said getting Lobi out of the corridor was just about as easy as squeezing toothpaste back into a tube.
Veasey and his team considered cutting out metal work to free the creature, but eventually built him a ramp made out of sandbags so that he could climb over a bar and back to his enclosure.
"Of course he's an angry hippo and he's trying to attack us and the sandbags as we're dropping them in, literally in front of his mouth."
Lobi did make it over — his hippo hide squeaking against the metal — and the crisis was over.
Keepers are working to hard to keep the giraffes warm and nourished. The zoo is particularly worried about a 19-year-old female named Carrie, who isn't eating as much as she should be.
"Giraffes are quite delicate animals, despite their size and strength," said Veasey.
"We're hopeful that the giraffe are going to pull through, but there is the potential that we may lose animals, including giraffes ... as the consequences of that stressful 48-hour period kick in."
So far, at least two peacocks that were free to roam the zoo grounds have died. In the mayhem following the flood, the birds crashed into objects and broke their necks.
The zoo also had to make the difficult decision not to rescue 140 tilapia fish that were in the hippo enclosure, because doing so would have taken too long and taken attention away from other animals. Six of the zoo's 12 piranhas also died.
Most of the zoo's animals are currently crowded into facilities elsewhere on the property in less than ideal conditions.
"We're now dealing with problems that are going to start arising due to stress, due to confinement and the sooner that we can remediate exhibits to bring animals back into their home enclosures, we can relieve stress on the animals."
Clement Lanthier, president and CEO of the zoo, said all the animals' enclosures will need to be inspected before they can return.
"We'll have to make a decision very soon if those spaces are not safe and sound. We'll have to start relocating some of our animals to other zoos," he said, adding that several other zoos have offered help.
He said it would be at least two weeks — possibly longer — before the zoo can open. It might be able to reopen in phases.
On Tuesday, many areas of the zoo were dry, but others were caked in thick mud. The island on which it's situated was still without power, but generators were humming.
The zoo's main restaurant, the Kitamba Cafe, was a mess, with leaves and branches strewn about. The kitchen was so damaged it will need to be gutted.
Hundreds of metres of fence need to be replaced after huge chunks of land eroded into the Bow river.
"The landscape of the zoo will change dramatically," said Lanthier.
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