In response to this predicted decline in water levels throughout the basin -- including and especially in the Great Lakes, the argument is put forward that "the construction of four additional control structures would make it possible to efficiently manage water levels throughout the entire basin, from Lake Superior to Quebec City, whatever the available flow, at an estimated cost of $5 billion to $6 billion."
The
Gazette article does raise some important policy and planning questions, which are also discussed in detail by a
Mowat Centre of the University of Toronto report that Gingras cites. A careful read of the
Mowat Centre report, however, appears to suggest caution on the climate change front. As the report notes, climate models vary widely when projecting future water levels in the Great Lakes and St. Lawrence (GLSL) basin. Indeed, the report devotes an entire chapter to the topic, entitled "The Uncertainty of Future Water Levels." The conclusion appears to be that the future levels of the GLSL basin cannot be reliably predicted.
Consequently, any policy and planning decisions should be based on this large uncertainty, and not on potentially highly unreliable viewpoints that water volumes and levels in the basin will fall "by 20 per cent to 30 per cent from existing levels over this 21st century." According to my understanding of the climate modeling review within the
Mowat Centre report, we simply do not know if water levels will decline, increase, or stay approximately constant over the rest of this century.
The historical
water level data in the basin supports a more cautious approach. Over the past few decades, water levels in the basin have declined, but since the start of records in 1918, there is some variation in trends. The level of Lake Superior has a significant declining trend, Lakes Michigan and Huron have a non-significant trend with a positive (increasing lake level) correlation, and Lakes St. Clair, Erie, and Ontario all have significant increasing trends. Overall, it appears that during the last century, there is a net increasing trend in GLSL water levels, notwithstanding the more recent three-decade long decline.
Is the current decline -- within a century long net increasing trend -- just part of a short-term cycle, or is it a longer trend that policy makers need to respond to? We do not know. If the trend over the last 30 years continues, water levels will decline over time. If the trend over the past century continues, it appears water levels throughout most of the basin will increase over time. Ambiguity abounds.
If such predictions of future water levels in the GLSL basin have high uncertainty, so do our policy and infrastructure planning and construction responses. Until predictions are better defined, the default position should always be one of doing nothing rash, i.e., maintaining the status quo as best as practical and continuing with a continuous and iterative optimization procedure as additional information and improved predictions become available. Avoid the water crisis shock doctrine approach to environmental policy making -- which was also
recently evident down
in Texas, and instead take a measured response that appropriately incorporates our uncertainties and the strong possibility that a cyclical phenomenon is at work.
