The province said it chose the Ghost Dam option due to its smaller project footprint and fewer overall impacts
The three options included building a dam near Mini Thni (the townsite formerly known as Morley); relocating the Ghost Dam; or building it on the eastern edge of Glenbow Ranch Provincial Park.
Wednesday’s announcement means the province will expand the existing Ghost Reservoir to protect downstream communities on the Bow River and provide water security for the river basin.
“Increasing water storage capacity is critical to protecting Calgary and other communities along the Bow River from future floods and drought,” Environment and Protected Areas Minister Rebecca Schulz said in a news release. “Based on the data collected in the study, one option, the relocated Ghost Dam, is clearly the best choice to move forward with.”
In its release, the province said it chose the Ghost Dam option due to its smaller project footprint and fewer overall impacts to the environment, property and infrastructure, while providing comparable water storage to the Glenbow East option.
The Glenbow East option posed higher risks to downstream communities during construction, according to the province, including Calgary.
“After reviewing multiple options, the Alberta government has determined that the relocated Ghost Dam option is significantly better than the Glenbow East option due to its lower cost, ability to mitigate future droughts and floods, and fewer social and environmental impacts,” the government said in a news release.
“Its earth-fill 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.”
An assessment in 2020 estimated the cost for the Glenbow East dam would have been $992 million, with the Ghost Dam and Morley options pegged at $917 million and $922 million respectively. The Morley price tag didn’t include land swaps and other possible compensation, however.
— With files from Bill Kaufmann
More to come …