Ghost Reservoir dam deal to help protect Calgary from flood over 5 years for $5.5M per year

Alberta will pay TransAlta $5.5 million a year for the next five years to use its Ghost River Dam to help protect Calgary from flooding and its Kananaskis dams to guard against drought.

The five-year deal extends an arrangement the power company has reached on a one-off basis with the Government of Alberta, as the only major flood-mitigation measure on the Bow River upstream of the province's largest city.

• Ghost Reservoir to be used for flood protection
• Ghost Reservoir levels lowered for flood prevention
• High water level at Ghost Dam not cause for concern, TransAlta says

Mayor Naheed Nenshi, who had been pressing for a long-term arrangement with TransAlta, welcomed the deal.

"This is a valuable agreement that will help protect Calgarians who live and work along the Bow River," he said in a release.

"This is not only an important investment in the protection of people and the environment, it's an investment in the resilience of our economy through the protection of downtown Calgary."

The deal offers protection to Calgary but doesn't guarantee the city will avoid damage in the event of another major flood.

Special operation of the dam and reservoir can mitigate against roughly 20 per cent of the volume of water seen during the 2013 flood, members of city council heard during a committee meeting Wednesday.

Summer control of Ghost Dam

The agreement means the province can dictate water levels at the Ghost Reservoir for flood-mitigation purposes between May 16 and July 7.

By keeping the levels lower than they would normally be, the excess dam capacity can be used to hold back water if there were to be a sudden high-water event.

Alberta Environment said last year's agreement provided an extra 65 million cubic metres of flood storage during the high run-off season.

The $5.5 million is to compensate TransAlta for lost hydroelectric generation capacity, in what is projected to be a break-even deal.

"TransAlta expects to cover lost revenue if and when water levels must be lowered and power cannot be generated for customers, but does not expect to make a profit," the company stated.

Drought mitigation, too

The new, five-year agreement also gives the province year-round control of reservoir levels at TransAlta's dams at Barrier Lake, Upper Kananaskis Lake and Lower Kananaskis Lake for the purpose of drought mitigation.

"Both flood and drought are serious concerns in southern Alberta," Environment Minister Shannon Phillips said in a release.

"This agreement provides more storage capacity and greater flexibility to help protect communities along the Bow River from the potentially devastating effects of flood and drought, and the uncertainties of a changing climate."

Western Irrigation District general manager Erwin Braun was pleased to have drought mitigation included as part of the deal.

"We want to make sure there is enough water to grow crops in a dry year," he said in a release.

"Good water management and collaboration are the keys to dealing with both flood and drought."

Ghost Lake Village residents impacted

Not everyone has been happy about the lower water levels on Ghost Lake, however.

Some residents of the Village of Ghost Lake complained last summer about the impact of the changes to the dam operations.

"My well is so low that my pump can't draw water out of it right now, and my neighbour's wells, three of the four houses have gone dry," Andre Vryheid told CBC News last June.

• Ghost Reservoir water levels frustrate residents
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Mike Weinert, owner of Ghost Lake Marina and campground, said the low water also impacted recreation on the lake, which his business relies on.

"This year we'll survive but I certainly can't do that for many more years," he said last summer.