By John Pomeroy Western Canada is undergoing the most rapid economic expansion in its history, an expansion that depends on adequate and reliable water resources for our communities, industry and agriculture. Water is also critical to aquatic life and the pristine environment that we cherish. Western water is currently unpredictable, misunderstood, and diminishing. We need better predictive tools if we are to manage our water resources in a responsible and sustainable fashion. Our country is steward to about 20 per cent of the world’s freshwater. Our cold regions – the Rockies and the Yukon and Northwest Territories – are the source of much of western Canada’s water. Yet we have limited ability to assess and predict the stability of this resource given shifts in land use and changing climate. We simply don’t understand the complex snow, glacier, permafrost, vegetation, wetland, lake, stream and climate systems that control water supply. Our ignorance is risky. Alberta and Saskatchewan cities, manufacturing, potash mines, and irrigation depend almost completely upon the Saskatchewan River system which delivers water from the Rocky Mountains to the Prairies with minimal contribution from local runoff. And river flows are dropping. Natural flows entering the South Saskatchewan River have dropped 15 per cent since the early 1900s. Low flow years in this river coincide with low spring snowpacks in the Rockies. Water use is closing in on our self-imposed limits: Alberta used up to 42 per cent of the natural flow in a recent low snowfall year – close to the limit of 50 per cent specified in the Prairie Provinces Water Board Master Agreement on Apportionment. Since 1912, there has been a decline in real flows of the South Saskatchewan River of about 40 per cent due to diminished supply and increased use. Further north, the Yukon and Mackenzie Rivers are growing economic development and population corridors, but stream flow has declined dramatically in the last 30 years. Proposed oil and gas developments involve hundreds of expensive bridges or pipeline stream crossings – yet we cannot predict how high to build these crossings to ensure cost-effective and safe engineering designs during spring floods. Floods also threaten riverside communities. Excessive runoff from the Rockies in June 2005 caused more than $420 million in flood damage in Alberta and Saskatchewan. Weather systems that affect all of the Northern Hemisphere are generated in our high mountains and northern latitudes. Better prediction of this weather – storm or drought – depends upon our knowledge of snowcover, lakes, and wetlands. Despite its many lakes and wetlands, water is not abundant in the North. Vast tracts of its lands are as dry, or drier, than the Prairies in terms of annual snowfall and rainfall. Only low evaporation and exceptionally poor drainage allow standing water to accumulate. Furthermore, modest streamflows limit the potential for industry and hydroelectricity, and do not effectively transport pollution away from the source. Water quality problems of northern settlements can be severe. Another widely-publicized but serious misconception is the link between declining glaciers in the Rockies and future water shortages on the Prairies. It is true that glacier-covered area in the Rockies has declined substantially: 37 per cent for the South Saskatchewan River basin and 22 per cent in the North Saskatchewan basin since 1975. The melt of these glaciers is important to local, glacier-fed mountain streams, but they are now so small they don’t contribute significantly to the river flow. Recent federal studies show glacier melt now accounts for less than 0.6 per cent of yearly flow of the Bow River at Calgary and less than 1.8 per cent in the North Saskatchewan River at Edmonton. Even in the driest months of late summer, glaciers now only account for 2.4 per cent and 7.8 per cent of monthly flow. Downstream storage and flow control reservoirs such as Lake Diefenbaker make the significance of these glacial contributions negligible. The flow of the Saskatchewan River system is driven largely by snowmelt. It is snowpack rather than further glacier decline that we should be concerned with. Water management demands more than conjecture; it must be based on sound scientific and engineering principles. The Centre for Hydrology at the University of Saskatchewan is directed toward improving understanding of water resources and developing hydrology as a geophysical science. National and provincial funding agencies have invested almost $3 million in hydrological research and facilities at the Centre. Most recently, the Canadian Foundation for Climate and Atmospheric Sciences committed $2.5 million to the Improved Processes and Parameterisation for Prediction in Cold Regions (IP3) Network. Based at the Centre for Hydrology, IP3 is a Canada-wide research network devoted to improving understanding of surface water and weather systems in cold regions, particularly in Canada's Rocky Mountains and Western Arctic regions: issues of key importance to agriculture, urban and industrial development. We cannot chart a responsible course with our water resources by flying blind. We need these strategic investments in research to develop the predictive tools we need to sustainable manage our water. Without them, our continued prosperity and the fate of our environmental treasures will both be in question. John Pomeroy is a professor of geography and Canada Research Chair in Water Resources and Climate Change at the University of Saskatchewan. |