4 Water Quantity for Domestic Needs

How much water must a domestic well provide to meet the needs of a household? Estimates vary greatly, ranging from about 70 to 300 L/day per person, depending on the type of fixtures in a house, personal habits and expectations, socio-economic conditions, and cultural factors. The lower estimate of 70 L/day per person is associated with domestic water needs during emergency situations, such as a camp for displaced persons during a natural disaster, of which 30 L/day is for drinking water and cooking (Figure 12). The upper limit represents typical water use in North America, where households use more water per capita than most other countries. In the United States, the average domestic water use is approximately 300 L/day per person (Dieter and Maupin, 2017). In Canada, the average domestic water use is approximately 215 L/day per person (Statistics Canada, 2019). The average domestic water use in European counties is 130 L/day per person (EurEau, 2017), which is about half the amount used in North America.

Figure showing domestic water needs during emergencies

Figure 12 Domestic water needs during emergencies (modified from WHO, 2011).

Most of the water needed for domestic purposes is for non-potable uses, such as washing and toilet flushing. A typical breakdown of domestic water use is 10 percent for cooking and drinking, 25 percent for laundry and cleaning, 30 percent for toilet flushing, and 35 percent for bathing (Environment Canada, 2011). The amount of water needed for non-potable purposes has been declining as newer water fixtures are made to use less water (e.g., water-efficient toilets, shower heads, clothes washers). This has caused per capita domestic water use to decline in recent decades. For example, in Canada, the average per capita domestic water use declined by 24 percent between 2005 and 2013 (Statistics Canada, 2017b), and in the United States it declined by 7 percent between 2010 and 2015 (Dieter and Maupin, 2017).

Water use in a household may be concentrated into a period of one or two hours. Therefore, a domestic well must be able to meet both the long-term average daily needs of a household and the short-term peak demands. The well yield must be able to meet the long-term daily household needs, but the short-term peak demands can be provided by a combination of the well yield and water storage, either from water stored in the well or from a storage tank incorporated into the home’s water system. The amount of water available from well storage can be calculated from the well depth, well diameter, the pump intake setting, and the static water level. Box 1 provides examples of how this calculation is done to determine if a domestic well can provide an adequate water supply.


Domestic Wells – Introduction and Overview Copyright © 2022 by John Drage. All Rights Reserved.