Ghost Dam to move downstream for flood, drought mitigation

The Ghost Dam will be relocated downstream as part of an extreme-weather mitigation plan aimed at floods of the once-a-century variety, such as the massive regional flood of 2013, the province has announced.

It will control a large body of water to be known as the Bow River Reservoir.

LISTEN | Discussing Ghost Dam water management:

Calgary Eyeopener8:06Bow River reservoir

The Ghost Dam will be relocated further downstream, in the latest attempt to protect Calgary from flooding.

The executive director of an environmental non-profit saysthere's good news here but the devil will be in details coming in the next phase.

"The Bow Valley is extremely important to us and for wildlife and diversity," Mike Murray of the Bow River Basin Council told the Calgary Eyeopener in a Thursday interview.

"By adding an expansion to an existing site, you are lowering some of your footprint, instead of two new sites. The amount of water that can be held back is comparable."

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Another option got the thumbs down, in part, due to pushback over possible flooding from residents of the town of Cochrane, just west of Calgary.

"The Glenbow East option posed higher risks to downstream communities during construction, including Calgary. Its earthfill dam would also be more susceptible to erosion and failure during large flood events compared to the relocated Ghost Dam, which is a concrete gravity dam," the Alberta government wrote in a Wednesday release.

The announcement concludes Phase 2 of the project, where three options were considered.

"Water management is very complicated," Murray said.

"The Ghost relocation seems to be the best option, because you are limiting how much change you are going to make in that area."

There are many factors to consider.

"You have to balance [mitigation objectives] with other needs. It's going to be a costly process, there are social and community interests at hand, as well as the environmental concerns."

The province's environment minister says the choice was clear.

"Increasing water storage capacity is critical to protecting Calgary and other communities along the Bow River from future floods and drought," Rebecca Schulz said in a release.

"Based on the data collected in the study, one option, the relocated Ghost Dam, is clearly the best choice to move forward with."

Phase 3 is next, covering engineering and regulatory approvals.