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Gauges washed away led to misreading Oldman River: AB Environment

Days after Oldman River peaked in Lethbridge, questions are now being asked why predictions were so far off and so rapidly changing.

You may recall Thursday afternoon, when officials closed schools and told parents to pick up their children from daycare, as it was anticipated Lethbridge’s two bridge crossings could close.

As it turns out, the river didn’t peak until 36 hours later and it was nowhere near the 1995 flood levels originally predicted.

One reason was revealed by flood forecasters on Tuesday morning.

“We lost guages,” said Evan Friesenhan of Alberta Environment’s River Forecast Centre, who also blames overland trapping of water. “I don’t just mean malfunctioning, but gone, as in completely washed away.

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All five floodgates opened at the Oldman dam on Thursday.

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Based on river flow rate, precipitation and soil moisture, computer models determine the need to warn communities downstream.

“From what we were told by Oldman River dam, a certain discharge was coming out of the dam,” said Friesenhan. “When it went past that location, the flows were much less than that, creating major issues for our models because it uses that date from what is coming from upstream.”

Questions also surround the dam’s release.

At Paradise Canyon Golf Resort, just metres from the river, a close eye is kept on the reservoir’s capacity.

All of June, that number was over 90 per cent, leading one to ask, why wait?

“What I’ve heard a lot is, ‘Below the dam, there aren’t a lot of people affected,’ ” said Mike Fleischhauer, Paradise Canyon’s general manager. “If you go to Fort Macleod, talk to farmers and ranchers, you go southeast of here, there are people affected.”

“Those people are probably waiting for the same answers we are.”

Global News contacted Alberta Environment.

A statement reads, “Our dam operators, river forecasters and water teams work extremely close together before, during and after a flood event. Appropriate information was shared and appropriate actions were taken.”

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That action having an unyielding impact downstream, where officials say the damage could have been much worse.

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