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Glaciers in the Purcell Mountains in BC Hydro's Columbia Region.

February 12, 2009

BC Hydro keeps an eye on shrinking glaciers

Posted by Rob Klovance

As if forecasting electricity demand isn't enough, global warming has thrown us another curveball. In a province where we're understandably proud – and fortunate – to get the majority of our power from clean and renewable hydroelectricity, we now have to be concerned about shrinking glaciers.

“Glacial contributions to our hydroelectric production have decreased over the decades as glaciers have been retreating,” says Sean Fleming, a hydrologic modeller working on BC Hydro’s Runoff Forecasting Team, and an adjunct professor at the University of British Columbia. “We look for an estimate as to what degree that will continue and how that will impact our total capacity, our operations and how that balances with other climate changes.”

The long-term outlook is not good – it was recently estimated that B.C.'s glaciers will disappear in the next 150 years. But it may not be as bad as it initially looks, or it may be worse.

According to Fleming, water lost from shrinking glaciers could either be compensated or aggravated by other climatic changes such as the timing of snow melt, temperature and precipitation.

“The question is how will these balance out to create a net impact on hydro power availability,” says Fleming.

BC Hydro hydrologists have begun to watch the rate of glacial recession in the province as part of a forecasting picture that goes as far as 2080.

The effects of glacial recession on water resources vary from one region to the next. In northwestern B.C. glacier recession is leading to stream flow increases, but in the southern part of the province – where most of Hydro’s glaciated watersheds are located – it’s leading to stream flow decreases. In both cases, the trend in glacier volume is reduction.

The two areas that the Runoff Forecasting Team are watching closest are the Columbia-Kootenay and Coastal-Bridge River regions. These areas include the highest percentage of the total area covered by glaciers in BC Hydro watersheds.

BC Hydro is working with other groups such as the Western Canadian Cryospheric Network and the Pacific Climate Impacts Consortium to study how glacial recession is going to affect bodies of water used for hydroelectric production.

To determine the specific effects of glacial recession on reservoir inflows, they use the output from global climate models for various emission scenarios and run those through hydrologic models.

“Basically we take all the climate models you hear about in the news and run each one with a number of emission scenarios,” says Fleming, pictured to the right in a photo at the Trapridge glacier in the Yukon. “Those projections of temperature and precipitation are then plunked into watershed models. We then make projections of how reservoir inflows will change.”

There will also be engineering studies on how hydroelectric generation will be affected by those projected changes in inflows. Hydrologic studies are already underway in the Bridge River region and plans are set to begin studies in the Columbia region.

In the end, it all comes down to this. Sooner, rather than later, we're going to have to get serious about reducing our energy consumption. It's a huge part of B.C.'s short-term goal of electricity self-sufficiency by 2016, and it's the best available answer we have to the ravages of global warming.

So, in case you're not already a Team Power Smart member, join now. And if you're already a member, keep plugging away at that 10% reduction goal and beyond. And think about spreading the word to those friends and family who may feel that because electricity is still a relative bargain in B.C., there's no real need to save.

Rob Klovance is managing editor of bchydro.com and, thanks in part to his slippers, is on his way to exceeding that 10% reduction goal for the second straight year.

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The views expressed in this blog do not necessarily reflect those of BC Hydro.