Sustaining our water supply

Water is considered a renewable resource: “renewable” referring to that portion which circulates back and forth in the hydrologic cycle. However, pressures on the resource are growing. For example, between 1972 and 1996, Canada's rate of water withdrawals increased by almost 90 percent, from 24 billion m3/yr (cubic metres per year) to 45 billion m3/yr. But, our population increased by only 33.6 percent over the same period, illustrating the growth in our thirsty lifestyles. As the readily available supplies of fresh water are being used up, we begin to see that there are real limits to how much water we can count on.

Limiting factors

• Although Canada has a significant amount of fresh water, we possess only seven percent of the world's renewable freshwater supply.
• In Canada, 84 percent of the population lives in a narrow southern band, while 60 percent of our water supply flows north to the Arctic Circle.
• Our growing population, and our growing thirst for water, are being concentrated in expanding metropolitan areas, and are forcing water regulators and policy makers to find ways to stretch available supplies even further.
• Increasing pollution of surface and groundwater is further reducing the supplies of readily available, clean water.
• Because our water use almost always leads to some degree of deterioration in water quality, the less water we withdraw, the less we upset the natural balance of our aquatic ecosystems. And, the less we upset the ecosystem, the less we have to spend to restore the water quality to an acceptable standard for public use.
• Finally, financing by municipal governments for the treatment of water supplies and wastewater is becoming increasingly constrained.

We can, however, make a significant contribution to solving these problems by reducing unnecessary levels of water use. To do so requires that we identify the areas within our homes, businesses, and processes where we waste water and then make appropriate changes, either in our fixtures, or in our water-using habits.