PUBLISHED: 30 July 2012

Canadian Water Facts

Canadian Water Facts

Water Supply

  • Annually, Canada’s rivers discharge 7% of the world’s renewable water supply – 105 000 cubic metres per second[1].
  • Mackenzie River is the longest river in Canada at 4 241 kilometres[1]
  • Wetlands cover an area of more than 1.2 million square kilometers(14% of Canada’s land areas) this is roughly 25% of the world’s wetlands. Making Canada the largest wetland area in the world[1]
  • Canada has 563 lakes having an area greater than 100 square kilometres[1]
  • Glacial erosion created a number of the lakes on the Canadian Shield, including the Great Lakes[1]
  • Almost 9%, or 891 163 square kilometres, of Canada’s total area is covered by fresh water[1].
  • Approximately 60% of Canada’s fresh water drains north, while 85% of the population lives within 300 kilometres of the southern border[1].
  • Currently, there are 2921 active water level and stream flow stations being operated in Canada[1].
  • Glacier ice over 100 000 years old is found at the base of many Canadian Arctic ice caps[1].
  • It is estimated that about 2% or 200,000 km2 of Canada is covered by glaciers and icefields. This is more lake area than any other country in the world[1].
  • Canada’s longest inland waterway stretches 3 700 kilometres from the Gulf of St. Lawrence to Lake Superior[1].


Water Demand

  • Residential indoor water use in Canada: toilet – 30%; bathing and showering – 35%; laundry – 20%; kitchen and drinking – 10%; cleaning – 5%[1]



  • 40% of Canada’s boundary with the United States is composed of water[1]
  • The Canadian Government has firmly expressed that they will not export water to foreign countries[2]
  • As of 2010, rivers and streams that cross the border with the United States now fall under the same protection that was already in place for waters that straddle the border, such as the Great Lakes[2].



  • Canada is the third largest producer of hydroelectricity in the world behind China and Brazil[3]
  • The largest hydro-electric power development in Canada is the James Bay project in Quebec, which started producing electricity in 1982[1]
  • Although the Canadian Dam Association register of dams (2003) reports 933 large dams in the country, there are many thousands of smaller dams[1]


Health and Safety

  • The most severe flood in Canadian history occurred on October 14 to 15, 1954 when Hurricane Hazel brought 214 millimetres of rain in Toronto region in just 72 hours[1].
  • Health problems related to water pollution in general are estimated to cost Canadians $300 million per year[1]
  • Floods are the most costly natural disasters in Canada in terms of property damage[1].
  • Between September 2001 and August 2002 drought affected over 65% of prairie cropland in Canada[1]
  • Among the worst floods in Canada’s recent history was Manitoba’s Red River flood of May 1997[1]

Regional Facts


  • The wetlands of Lake Ontario have suffered severe loss over the last two centuries due to agricultural drainage and urban encroachment[1].
  • The first Canadian Heritage River was the French River in Ontario, designated in 1986[1]

Great Lakes

  • The Great Lakes support 45% of Canada’s industrial capacity[1].
  • The Great Lakes sustain a $100 million commercial fishing industry and a $350 million recreational fishing industry[1]
  • The Great Lakes provide drinking water to 8.5 million Canadians.
  • 25% of Canadians agricultural capacity is supported by the Great Lakes[1].
  • Only 1% of the waters of the Great Lakes are renewed each year by snow melt and rain[1].
  • The Great Lakes are the largest system of fresh, surface water on earth, containing roughly 18% of the world’s fresh, surface water[1].
  • The combined shoreline of the Great Lakes is equal to about 45% of the earth’s circumference[1].
  • Severe storms on Lake Erie can result in short term lake level changes of up to 4 metres[1]


  • For more interesting facts specific to Alberta, see our page on Alberta Water Facts.
  • The Prairie Provinces contain roughly 770 dams[1].
  • About 75% of all agricultural water withdrawals in Canada take place on the Prairies, mainly for irrigation[1]
  • 15-25% of the Prairie Region is wetland[1]
  • A farm dugout, a small on-farm reservoir, is a common type of surface water source on the Canadian Prairies[1].  


  • Quebec has more dams than any other province with 333 large dams[1]
  • The 1996 Saguenay basin storm and associated flood in Quebec led to 10 deaths and over $1500 million in damages[1]
  • Levels of organic contaminants (PCBs) and inorganic contaminants (Cu, Zn, Pb, Hg, Cd and As) in the sediments of northern Lake Saint-Pierre have fallen by 50% since 1986[4]
  • The St. Lawrence–Great Lakes hydrographic system is one of the largest in the world. It drains more than 25% of the Earth’s freshwater reserves and influences environmental processes across much of North America[4].
  • The St. Lawrence is made up of five main water masses and nine secondary water masses associated with the main tributaries. Each of these water masses has its own distinct natural physical and chemical characteristics[4]
  • The Quebec portion of the St. Lawrence River widens in three places, forming stretches of open water large enough to be considered lakes, but with a typical river flow. These three fluvial lakes are Lake Saint-François, Lake Saint-Louis and Lake Saint-Pierre[4].


  • Everyone on Prince Edward Island uses groundwater to meet their daily water needs.
  • The majority of the Prince Edward Island (57%)  depend on private wells for their water supply.
  • The Eel River Bar, is one of the longest natural sandbars in North America. Fresh water laps its shores on one side, salt water on the other[5]
  • At low tide, watch the Saint John River crash through a narrow gorge and tumble into the harbour, but during high tide the same river flows in the opposite direction. The Bay of Fundy’s incredible tides are too strong for the Saint John River, forcing the waters to flow upstream twice a day, every day[5].
  • In 2000, the Kennebecasis Watershed Restoration Committee (KWRC) reported 24 different species of fish from 13 different families. Some of the more common species found include the Atlantic salmon, rainbow trout & striped bass[5].


  • Great Bear Lake, located in the Northwest Territories is the largest lake in Canada at 31 328 square kilometres[1]
  • The deepest lake in Canada is Great Slave Lake, located in the Northwest Territories, with 614 meters being the deepest point.   
  • In Canada, the individual river system with the largest drainage area is the Mackenzie River, with 1 805 200 square kilometres[1].


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