One major aspect of environmental sustainability has to do with sustainable water consumption. Unlike many other resources, the physical quantity of water on earth is effectively constant, with a volume of approximately 1.386 billion cubic kilometres existing within the bounds of earth’s atmosphere. It can be found in the following places:
Aside from being pretty important in the lives of biological organisms, water is used in many ways by humans. Two major considerations in the sustainability of water are consumption within the limits of renewable fresh water and minimizing pollutants which have adverse effects on organisms that use the water.
Here are some statistics about the consumption of freshwater. The volume of water that is replenished by rain is considered renewable water. Sources such as groundwater are not renewable since they are replenished very gradually. Surface water sources, such as rivers, that are active parts of the water cycle are renewable only up to the point that the volume of water used will be replaced by rain. Because not all the water on earth is accessible or useful, it is important to consume water in a sustainable way that does not exceed the total renewable freshwater resources available.
On earth, humans withdrew 3985.682 billion cubic metres of freshwater in 2014 for the following purposes:
In Canada water is used in slightly different proportions than in the world as a whole.
The total freshwater withdrawal of Canada in 2014 was 38.8 billion cubic metres. 838 million cubic metres of this water was used for irrigation of crops. While irrigation levels vary by province, the highest average volume of water used for irrigation of an individual farm in 2010 was 254000 cubic metres. Of the 7685 Canadian farms that used water for irrigation in 2010, the water used was from the following places:
The following chart shows how much water various industries used in Canada in 2009.
After use, manufacturing industries discharge remaining water, typically into surface freshwater sources.
As for domestic use of water, the average Canadian living in a household served by a municipal water system used 91615 litres, equivalent to 91.615 cubic metres, in 2011.
So, those were some facts about water use. The links to the sources where all this data came from are below.