Residential water use in the U.S. and Canada
The approximate average quantities of water applied toward specific purposes have to be estimated because only total use of residential customers is metered and recorded for time periods of one month or longer (although the AMR and advance metering infrastructure (AMI) technologies allow for more frequent readings).
[3] In the United States, a nationwide compilation of these metered quantities by the United States Geological Survey (USGS) shows average domestic water deliveries (for both indoor and outdoor purposes) by public water suppliers to single-family and multifamily dwellings were about 89 gallons (337 liters) per person per day in 2010[4] and 83 gallons (314 liters) in 2015.
Because the distribution of indoor use in the sample of homes is positively skewed, a more appropriate measure of central tendency is the median, which is about 125 gphd (or 472 lphd).
Toilet flushing is the largest indoor use of water, followed by flows through kitchen and bathroom faucets, showers, clothes washers, leaks, bathtubs, other/miscellaneous uses, and dishwashers.
Since the late 1990s, total indoor use has decreased by 22 percent, primarily due to the improved water efficiency of clothes washers and toilets, among other low-flow fixtures.
Toilet flushing makes up about 24% of overall household water consumption (at average daily volume of 33.1 gphd or 125 lphd).
A recent study shows that about 21 percent of all toilets in 5 states (Arizona, California, Colorado, Georgia and Texas) have a flushing volume that exceeds 1.6 gallons/flush.
A widespread use of more efficient showerheads (with flow rates of 1.6 gpm) would reduce average water use for showering by 2 gphd (7.6 lphd)(or by 8 percent).
Dishes can be washed by hand in a sink or in an automatic dishwasher (DW), which was present in 84 percent of the end use study homes.
[1] The average water volume per load was 6.1 gpl (23 lpl) and dishwashers accounted for about 1 percent of total indoor use.
Significant reductions in some end uses of water could be achieved not only through the adoption of efficient technologies (i.e., fixtures and appliances) but also through consumers' small behavioral changes to reduce water use and wastage and by eliminating customer side leakage through automated metering and leak alert programs.
