Industry is Canada's largest water user, using 30.6 billion cubic metres in 2009 to cool machinery and equipment, produce energy, clean goods for manufactured items, and act as a solvent.2 Of the industrial water users, thermal-electric power producers withdraw 86 per cent. Manufacturers take 12.4 per cent—where water is mainly used in paper industries, primary metals industry, and chemicals industries. Mining industries are responsible for 1.6 per cent of total industrial withdrawals.
It is important to note that industrial and thermal-electric water withdrawals are fundamentally different from net consumption. Water withdrawal measures the total amount removed from the watershed, including volumes that are returned. When water is used for cooling by industry, the net consumption is often 10 per cent or less of the gross withdrawal. It is also important to note that almost all industrial water in Canada is taken directly from the watershed and is not purchased from a water utility. Water pricing for industrial purposes refers to any fees associated with water allocations, not to the cost of municipal water.
Average residential water use per person dropped slightly from 335 litres per day in 2001 to 327 litres per day in 2006.3 Domestic water use includes drinking water, as well as all water withdrawn for homes, municipalities, commercial establishments, and public services like hospitals.
Residential water use per capita is generally lower in cities and larger communities than in smaller communities. For example, residential per capita water use averaged 294 litres per day in cities with a population greater than 500,000 or more, compared with 496 litres per day in municipalities with a population of between 2000 and 5000.4 This may be linked to water metering and volume-based pricing. Homes, institutions, and businesses in cities and larger communities are more likely to have water meters than those in smaller communities. Municipalities that charge according to the volume of water used have a lower average daily consumption rate.
Main agriculture water uses include irrigation (85 per cent) and livestock watering (15 per cent). Irrigation needs differ among the various regions of Canada. Some areas, such as southern Alberta, have a relatively large portion of land under irrigation. Other regions, such as Quebec, have a very small portion of the arable land under irrigation. Irrigation is needed mainly in the drier parts of Canada, such as the southern regions of Alberta, British Columbia, and Saskatchewan. These regions account for 85 per cent of all irrigation in Canada.
Some water users are more efficient than others. When the amount of water returned to the environment is taken into account, the proportions change considerably. Water use in agriculture is particularly inefficient, returning less than 30 per cent of water consumption.5 That's why agriculture represents the largest consumer of water in Canada.