In Canada, an estimated area of 200 000 square kilometres, or about 2% of the country’s total area is covered by glaciers and icefields. A huge quantity of freshwater is frozen in the polar ice caps and in high mountain glaciers. Glaciers exert a direct influence on the water cycle by slowing the passage of water through the cycle. Like groundwater, glaciers are excellent natural storehouses of water. Glacier-fed rivers, which include many of the largest rivers in Alberta and British Columbia, reach their peak flow during hot summer weather when other sources of water in these regions may be scarce. They are, therefore, extremely important to the relatively dry Prairie region as sources of water for irrigation, electric power, and uses by communities located close to these rivers.
