List of longest rivers of Canada
Nine rivers in this list cross international boundaries or form them. Four—the Yukon, Columbia, Porcupine, and Kootenay—begin in Canada and flow into the United States. Five—the Milk, Pend d'Oreille, Saint Lawrence, Red, and Saint John—begin in the United States and flow into Canada. Of these, the Milk and the Kootenay cross the international border twice, the Milk leaving and then re-entering the United States, the Kootenay leaving and then re-entering Canada. The drainage basins of these nine rivers extend into both countries; in addition, the drainage basins of six others—the Fraser, Assiniboine, South Saskatchewan, Saskatchewan, Nelson, and Winnipeg—extend into the United States even though their main stems flow entirely within Canada.
Okanagan Basin Water Board
Water is one of the most precious and important natural assets in the Okanagan Basin. Even though the Basin is endowed with several large lakes, the supply of clean, reliable water is inherently limited by the semi-arid to arid climate, which brings minimal precipitation and high evaporation and evapotranspiration rates. In fact, according to Statistics Canada the Okanagan Basin has the lowest, per capita availability of fresh water in Canada. Water shortages have already occurred in some areas of the Basin, and are expected to occur more widely and frequently in the future.