Dominated by the Great Lakes–St. Lawrence River Basin, the Atlantic Ocean watershed in Canada spans more than 1.5 million square kilometres. Other major watersheds within its boundaries include the Churchill River in Labrador and the Saint John River in New Brunswick. Industry in the region is considerably thirsty, using 27.5 billion cubic metres of water each year, which amounts to withdrawing just over 12 percent of the area's annual surface flow.
Great Lakes Basin
The Great Lakes Basin is home to approximately one out of every four Canadians, for whom the lakes provide drinking water, a sewage outlet, hydroelectricity and recreational opportunities. It is also the backdrop for massive industrial, commercial, agricultural and urban development. And the flow from Lake Erie to Lake Ontario forms that iconic vista: Niagara Falls.
Spreading across nearly a quarter of a million square kilometres, the Great Lakes Basin, which includes Lakes Erie, Huron, Michigan, Ontario and Superior, and traverses parts of eight American states and two Canadian provinces. Together, the Great Lakes are the world's largest surface freshwater system, containing 21 percent of the planet's fresh water. Ninety-nine percent of that water, however, is the leftover ancient glacier melt and is non-renewable.
St. Lawrence River
The St. Lawrence is Canada's third longest river, boasting the highest discharge of any Canadian river. But it has been drastically altered from its natural state due to centuries of exploration and commerce conducted along its shores. The St. Lawrence system has been dammed for hydropower, diverted and dredged to form the St. Lawrence Seaway, one of the world's busiest shipping corridors. As a result, wildlife in the river has paid the price. More than 20 animal and plant species in the St. Lawrence system are listed as vulnerable, threatened or endangered. Yet it continues to be the lifeblood of the region, providing 45 percent of Quebec residents with water.