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.
Water resources management in Guatemala
The hydrographic system is divided into three primary drainage basins. First, the Pacific Ocean drainage basin covers 22% of the country and counts 18 watersheds. Some of the rivers in this zone transport volcanic sediments to be deposited along the coast and contributes to coastal flooding due to reduced depths of tidal marshes. Annual surface runoff in this basin is 25.5 km. The Caribbean Sea drainage basin covers 31% of the country and has 10 watersheds. Average annual surface runoff in this basin is calculated at 31.9 km. The Gulf of Mexico basin covers 47% of Guatemala and 10 watersheds. The rivers in this basin have the largest flows in the country and drain towards Mexico. Surface runoff in this basin is 43.3 km.