75,000 People Forced From Their Homes as Calgary, Alberta, Floods

More rain and snow melt than the city can handle

Rivers fed by torrential mountain rains spilled across the prairies of southern Alberta Friday, turning Calgary streets into rivers and threatening to wash away a similarly monstrous flood in 2005 as the western Canadian province's most costly natural disaster.

Calgary Mayor Naheed Nenshi said the Bow and Elbow rivers were carrying as much three times as much water through Calgary as they did during that flood, which obliterated roads, chased residents from their homes and drowned livestock on the way to causing more than $400 million in damages.

"The Bow River looks like an ocean at the moment," he said.

Even as Calgary was dealing with the brunt of the flooding, residents downstream of the city—backed by engineers rushed into place by the Canadian military—braced for the coming floods.