Panel recommends extra outlets for flood-prone lakes

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This article was published 06/04/2013 (4812 days ago), so information in it may no longer be current.

A panel examining the regulation of two large flood-prone Manitoba lakes has recommended additional outlets be built to better regulate them.

On Friday, the Lake Manitoba/Lake St. Martin Regulation Review Committee said a second channel should be constructed between Lake Manitoba and Lake St. Martin, with water from the former draining into the latter.

The goal would be to provide a total outlet capacity for Lake Manitoba in line with the original design of the Fairford Control Structure.

In its 140-page report — one of two government-commissioned studies released Friday on the 2011 flood — the committee said there was “an overwhelming interest and demand” from Manitobans for a second Lake Manitoba outlet.

“Many have suggested that additional outlet capacity must be sufficient to avoid the flooding that would be experienced in a repeat of a 2011-sized flood,” the report’s authors said.

But the cost of building a channel capable of handling so much water for such a rare event would be hard to justify, they said. Instead, they suggested a smaller outlet and recommended the province undertake the necessary engineering studies.

The committee also recommended the emergency channel built to reduce pressure on Lake St. Martin be made permanent. It had to be closed once the emergency passed because it was constructed without the usual environmental approvals.

No cost estimates were provided.

Harold Westdal, chairman of the regulation review committee, said his group is also urging the province to lower water levels on Lake Manitoba for five years.

He said the move is necessary to re-establish shoreline vegetation. It would also mean the lake would “start from a slightly lower level” in case of a future flood.

Westdal said although it was outside the committee’s terms of reference, the group recommended the government increase the capacity of the Assiniboine River downstream from the Portage Diversion.

He said much of the damage caused by the operation of the diversion in 2011 was not due to its increased capacity but to the “exceedingly long period of time” that it operated that year.

“It ran for over 100 days,” Westdal said of the diversion. “Typically… it might have been running for 14 days.”

Also outside the regulatory committee’s purview was the question of whether flooding along Lake Manitoba and Lake St. Martin was artificial — caused by flood-control operations designed to protect Winnipeg and other centres. Westdal said the issue was “top-of-mind” whenever the committee met with the public.

While the matter is complex and far from clear cut, it was clear where the public stood, he said. “I think for the people around Lake Manitoba, though, the answer is pretty simple: As far as they’re concerned there were measures that were taken that knowingly led to flooding on Lake Manitoba and Lake St. Martin.”

— Larry Kusch