A Statistics Canada study found fresh water supply is dropping on average by an amount that equals 1.4 million Olympic-size swimming pools or about the volume of Lake St. Clair a year. Water yield, from precipitation and melting snow and ice, declined overall by 8.5 per cent in southern Canada between 1971 and 2004, declining on average by 3.5 cubic kilometres a year.
Canadians used about 1.2 per cent of the average water yield in 2005. 34% of Canadians live in the Great Lakes drainage region but it only produces 4% of the national renewable water yield.
This century will bring damage to Canada's lakes and rivers and the fish that live in them beyond Canadians' worst nightmares, the country's best known water scientist will tell a conference today.
"Considering its importance to all life on Earth, it is strange that fresh water has been our most mistreated and ignored natural resource," says David Schindler of the University of Alberta.
"Canadians have a rather cavalier attitude" toward lakes, swamps and rivers, probably because we have so many of them.
Mr. Schindler says the many problems in our fresh waters may not seem too bad, individually. But the problems interact to make each other's effects worse, he says. For instance, global warming makes lakes more vulnerable to acid rain, and acidic water makes fish more vulnerable to UV light coming through a thinned ozone layer. He calls the three together "a triple whammy."
"The overall effect will be the degradation of Canadian fresh water on a scale that was not comprehensible to the average Canadian at the end of the 20th century," he writes in this month's Canadian Journal of Fisheries and Aquatic Sciences.
His keynote speech today at an environmental conference in Toronto will based on this article, and the journal itself is sponsoring the environmental conference on lakes, rivers and fisheries.
As a new century starts, he sees many dangers coming together, With global warming underlying all of them.
"Increased research and a national water strategy offer the only hope for preventing a fresh water crisis in Canada," his article concludes.
Mr. Schindler is a former researcher with the Department of Fisheries and Oceans.
Last month he was one of three finalists for the $1-million Gerhard Herzberg Canada gold medal, given to Canad's top science researcher, and he has won two blobal prizes given to water scientists for life-time research.
Among the threats he sees:
Great Slave Lake hasn't been studied in detail since 1956, but is now having to cope with mining pollution, fisheries and industrial pollutants. Great Bear Lake "has never been comprehensively studied." Both are in the Northwest Territories.