Where fly fisherman Shane Olson once paddled summer tourists around in a boat, he now guides them by foot – carefully navigating shallow waters one step at a time. “Every year, these rivers seem to be getting smaller, faster,” Olson, 48, said, whipping a gleaming fishing line over the Crowsnest River about 70 kilometres from the U.S. border. It is an alarming trend in Canada’s breadbasket, and a sign of water scarcity to come as climate change speeds the melting of Rocky Mountain glaciers feeding rivers that deliver water to some seven million people across the Prairies.