...continued from Part 1
By 2050, scientists anticipate B.C. will be about six per cent wetter overall, but summers will be hotter and drier. Winters – particularly in the north – will be warmer and wetter, which means some of the precipitation that used to fall as snow will fall as rain.
Although the projected increase in precipitation means the utility does not expect glacier loss to hurt power generation, the shift from snow to rain may affect the way they store water. Glaciers and snowpack release water throughout the summer and act as a reliable, natural reservoir for BC Hydro. Rain is much harder to predict.
Darren Sherbot, BC Hydro’s manager of system optimization in generation, says the utility is already starting to struggle with precipitation falling as rain instead of snow.
“We had several record flood events [on Vancouver Island] this year, just because we had rain instead of snow and our reservoirs were full, and we couldn’t manage that,” he says.
Right now, however, he says Hydro has no plans to make reservoir capacity bigger to compensate.
You can still see the characteristics of the glacier water in the river when it gets to Terzaghi Dam just outside Lillooet. The water in the reservoir is bright green. There is no fish ladder at Terzaghi, and after the dam was built, the salmon population, on which local First Nations depended for hundreds of years, dwindled dramatically.
Today, band members no longer fish in the Bridge River. Instead, they use the Fraser, right by the confluence where water from the Bridge empties into the larger river.
“Because there aren’t enough fish [in the Bridge] … we leave them alone,” says Gerald Michel, the Xwisten fisheries and land use co-ordinator. “We try to help them increase their numbers.”
However, Mr. Michel is worried that the water in the Fraser is too warm. When it gets above 20 C, the chances for disease and infection in the fish are higher.
Young salmon will have higher mortality rates, and adult salmon returning to the Fraser to spawn may die before they can hatch a new generation.
The dam regulates the volume of water from the Bridge being released, so some cold water still makes it downstream and into the Fraser in dry years, but Mr. Michel does not know what will happen as the glacier and snowpack dwindle and more snow falls as rain.
Similarly, the Nooksack Indian Tribe in Washington is investigating whether salmon in the Nooksack River will be able to survive the eventual disappearance of glaciers in the area.
Mr. Michel has spent most of his life downstream from a retreating glacier, so he will see the changes sooner than most. As glaciers leave the landscape, Prof. Clarke predicts, the rest of the country will be altered as well.
“I think quite a lot of the national identity is connected with the fact that we are kind of a country with real winter, and glaciers are part of a particular sense of what Canada is,” he says. “So we’re going to lose that.”
Number of glaciers in B.C. and Alberta: approximately 17,595 (from a 2005 inventory)
Number in the world: almost 200,000
Common feature: almost all of world’s glaciers are in retreat
Water lost: 22 billion cubic metres every year from B.C. glaciers alonehttp://www.theglobeandmail.com/news/british-columbia/troubled-waters-face-bcs-bridge-glacier/article27985100/?cmpid=rss1