Global warming could wreak havoc with Canada’s prized freshwater supply over the next 100 years, sapping some of the country’s hydroelectric power potential, lowering lake levels and paving the way for more severe drought, a new report says.

The paper from Natural Resources Canada details a horror show of potential problems that could result if global surface-air temperatures increase between 1.4 to 5.8 degrees C by 2100 as climate-change researchers predict.

“Changes of this magnitude would significantly [affect] water resources in Canada,” says the water resources section of a bigger study called “Climate Change Impacts and Adaptation: A Canadian Perspective,” which cautions that predictions in this area are inexact.

The report says potential effects of climate change might include:

* Increased likelihood of severe drought on the Prairies, parts of which are suffering through their second or third consecutive drought this summer;

* A shrinking supply of potable water and more illness from contaminated water;

* Ruined fish habitat and spawning areas and possible loss of species;

* A Complete drying-up of some lakes in the Arctic and sub-Arctic region.

The paper summarizes the past five years of research on climate change. It warns that warming temperatures could shrink the supply of snow-melt-generated freshwater available during summer months when water is already in high demand. “Across southern Canada, annual mean streamflow has decreased significantly over the last 30 to 50 years, with the greatest decrease during August and September,” the report says.

The quality of Canada’s freshwater may also suffer from more extreme conditions brought on by climate change, the report says. “Lower water levels tend to lead to higher pollutant concentrations, whereas high-flow events and flooding increase turbidity and the flushing of contaminants into the water system.”

Hydroelectric power in southern Canada, where most of the population lives, might also be hit by climate change, the report says. “Studies suggest that the potential for hydroelectric generation will likely rise in northern regions and decrease in the south, due to projected changes in annual runoff volume,” it says.

The added pressure on hydro power might be greatest during warmer summers ahead when water levels are lower. Then, “more frequent and intense heat waves” will “increase air-conditioner usage and therefore electricity demand.”