Household Water Use

AEX-420
Agriculture and Natural Resources
Date: 
05/27/2020
Karen Mancl, PhD, Professor, Food, Agricultural, and Biological Engineering, Ohio State University Extension

Household water use is on the decline, which is good news. Water use by families was steadily increasing since the 1950s reaching its peak in the late 1990s. The required use of low-flush toilets and the introduction of low-water using washing machines is making all the difference. Water use per person has decreased 15% over the 17-year period 1999 to 2016, from an average of 60 gallons to 51 gallons per person per day. The biggest reductions were in water used to flush toilets and wash clothes. Figure 1 shows the typical household water use.

Modified pie chart that breaks household water into these categories and percentages: Flushing toilet 28%, Washing clothes 19%, Bathing 25%, Cleaning 23%, and Cooking & Drinking 5%.

Figure 1. Typical household water use (2016).


Whether the household gets their water from a public water system or their own well (13% of the population), using less water saves money. Less water means fewer treatment chemicals, less pumping costs, and lower demand for heating water. Using less water also reduces the demand on sewage treatment and septic systems, lowering sewage treatment costs. 

Household water leaks remain a problem and have been found to increase water use by 9.5 gallons per household each day. Efforts to fix a leaking faucet or running toilet can have a big impact.  

The amount of water used by fixtures has changed over the years. The most significant changes were in toilets (Table 1) and washing machines (Table 2). The current federal standard for toilets is 1.6 gallons per flush down from the 5 to 7 gallons per flush of older fixtures. WaterSense labels show the fixture has passed third party testing for performance and efficiency. Some new toilets use even less water at 1.28 gallons per flush. 

The biggest household water savings come from washing clothes. New machines use less water per load with front loading washers having the biggest water savings. It is worth replacing an old appliance or fixture to save water.

Table 1. Changes in toilet water use over time.
  Toilet (gallons per flush)
Before 1950 7.0
1950 - 1980 5.0
1980 - 1994 3.5 – 4.5
After 1994 1.6

 

Table 2. Changes in washing machine water use over time.
  Washing Machine (gallons per load)
Before 1980 56
1980 - 1990 51
After 1990 43
Front-loading 27


References

Water Research Foundation. 2016. Residential End Uses of Water. waterrf.org/research/projects/residential-end-uses-water-version-2

Swistock, BR and WE Sharpe. 2016. Water Conservation – How Much Water and Money Can You Save? Penn State Fact Sheet. extension.psu.edu/water-conservation-how-much-water-and-money-can-you-save