Contents
- Residential water use statistics: household totals and indoor use
- Residential water use statistics: toilets, faucets, and leaks
- Residential water use statistics: laundry, dishwashers, and other fixtures
- Residential water use statistics: showers, bathing, and hot water
- Residential water use statistics: outdoor demand and regional variation
- Residential water use statistics: U.S. domestic water supply
- Sources
Residential water use statistics: household totals and indoor use
Household water use varies widely across the homes and study sites measured. In the Residential End Uses of Water Version 2 study (REU2016), billing records for 23,749 homes across 23 sites showed average annual household use of 88,000 gallons, with a standard deviation of 32,000 gallons. The median was 83,000 gallons. Site averages ranged from 44,000 to 175,000 gallons per household per year. The billing data were mostly from 2010, so these figures describe that study’s participating homes, not a current national average. (Water Research Foundation, Residential End Uses of Water, Version 2: Executive Report)
The same report put average indoor use in its single-family study households at 138 gallons per household per day. A separate sample of homes built to EPA’s WaterSense New Home Specification Version 1.0 averaged 110 gallons per household per day. Because this is a comparison between distinct samples, it does not by itself establish why their averages differed. (Water Research Foundation, Residential End Uses of Water, Version 2: Executive Report)
EPA offers a broader general reference: the average American family uses more than 300 gallons of water per day at home, and roughly 70% of that use occurs indoors. The page does not specify an observation year or household details for this estimate. EPA also says outdoor use accounts for 30% of household use nationally. These broad figures are useful context, but their scope and underlying measurement details differ from the specific WRF study samples. (U.S. EPA, “How We Use Water”)
Residential water use statistics: toilets, faucets, and leaks
In REU2016, toilets were the largest listed indoor end use, accounting for 24% of average indoor single-family household use, or 33.1 gallons per household per day. Faucets accounted for 19% (26.3 gallons), while leaks accounted for 12% (17.0 gallons). These are corrected values from the report’s erratum; the first printing’s Figure 1 contained errors. (Water Research Foundation, REU2016 Erratum)
| REU2016 indoor use | Share of average indoor use | Gallons per household per day |
|---|---|---|
| Toilets | 24% | 33.1 |
| Faucets | 19% | 26.3 |
| Leaks | 12% | 17.0 |
| Clothes washers | 17% | 22.7 |
| Dishwashers | 1% | 1.6 |
| Other indoor uses | 4% | 5.3 |
Shares and daily volumes are the corrected Figure 1 values for average indoor single-family household use in REU2016. “Other” includes evaporative cooling, humidification, water softening, and uncategorized indoor uses. (Water Research Foundation, REU2016 Erratum)
The two WRF study editions also report indoor use per person, which helps compare end uses without confusing household size with fixture demand. Average daily toilet use was 18.5 gallons per capita in REU1999 and 14.2 in REU2016. Leak use was 9.5 and 7.9 gallons per capita per day, respectively. Faucet use was 10.9 in REU1999 and 11.1 in REU2016. These are values from two study samples, not a continuous national time series. (Water Research Foundation, Residential End Uses of Water, Version 2: Executive Report)
The 1999 study measured an average of 3.48 gallons per toilet flush across its 12 sites, with a standard deviation of 1.19 gallons. Participants averaged 5.05 flushes per person per day. Among 1,188 logged homes, 101 (8.5%) used ultra-low-flush toilets almost exclusively; this group averaged 9.5 gallons per capita per day for toilet use. The 2016 study found that 37% of its homes had average flush volumes below 2.0 gallons, compared with 8.5% in the 1999 sample. The studies’ samples and periods differ, so this comparison should not be read as a national adoption estimate. (Water Research Foundation, Residential End Uses of Water (1999); Water Research Foundation, REU2016 Erratum)
Residential water use statistics: laundry, dishwashers, and other fixtures
Clothes washers represented 17% of average indoor single-family use in corrected REU2016 figures, or 22.7 gallons per household per day. Dishwashers represented 1%, or 1.6 gallons. In the per-capita comparison between WRF editions, clothes-washer use averaged 15.0 gallons per person per day in REU1999 and 9.6 in REU2016; dishwasher use averaged 1.0 and 0.7 gallons, respectively. Those comparisons reflect each study’s participating homes. (Water Research Foundation, REU2016 Erratum; Water Research Foundation, Residential End Uses of Water, Version 2: Executive Report)
The 1999 study logged an average of 0.96 laundry loads per day across 1,188 households, including 26 homes that reported having no clothes washer. The average observed washer volume was 40.9 gallons per load, with a standard deviation of 12.2 gallons; the median was 39.8 gallons. Three-quarters of observed loads used between 25 and 50 gallons. This is historical monitored-use evidence, not a current machine-efficiency benchmark. (Water Research Foundation, Residential End Uses of Water (1999))
A separate REU2016 monitored subset of 94 homes measured hot water by end use. Clothes washers averaged 4.4 gallons of hot water per household per day, equal to 9.7% of monitored hot-water use. The subset’s small size and focus on hot water mean these values should not be substituted for the larger study’s general end-use averages. (Water Research Foundation, Residential End Uses of Water, Version 2: Executive Report)
Residential water use statistics: showers, bathing, and hot water
In the 1999 residential end-use study, researchers recorded 48,727 shower events over two years. An average event used 17.2 gallons, lasted 8.2 minutes, and had a reported mean flow rate of 2.1 gallons per minute. A separate summary of recorded shower durations found that 71.5% lasted between 4 and 10 minutes; the median was 7.2 minutes. Across the 12 study sites, mean shower flow was 2.2 gallons per minute and the median was 2.02. The event-level and site-level flow figures come from different reported summaries. (Water Research Foundation, Residential End Uses of Water (1999))
The same study’s logged-home average for shower use was 11.6 gallons per capita per day. In the later REU2016 monitored hot-water subset of 94 homes, showers used an average 17.8 gallons of hot water per household per day, or 39.1% of monitored hot-water use. Faucets accounted for 15.4 gallons (33.8%), and baths for 2.6 gallons (5.7%). In total, the monitored homes averaged 45.5 gallons of hot water per household per day, equivalent to 33.2% of their measured indoor water use. This subset describes hot water in those monitored homes, not all homes in the larger study. (Water Research Foundation, Residential End Uses of Water (1999); Water Research Foundation, Residential End Uses of Water, Version 2: Executive Report)
Residential water use statistics: outdoor demand and regional variation
Outdoor use can be a substantial share of a household’s total, but it varies with the homes and study groups being measured. EPA says outdoor water use accounts for 30% of household use nationally, without specifying the observation year or the underlying sample on its page. By comparison, the 1999 WRF study’s logged-home figure reported average outdoor use of 100.8 gallons per capita per day. That historical study value is not a current national estimate and is expressed per person rather than as a share of household use. (U.S. EPA, “How We Use Water”; Water Research Foundation, Residential End Uses of Water (1999))
Within REU2016, a Landscape Group of 838 homes averaged 101,000 gallons of total household use annually. Outdoor use accounted for half of that, or 50,500 gallons per household per year. The report also classified participants by actual irrigation relative to theoretical irrigation requirement: 72% applied less than 70% of the requirement, 16% fell within 70–130%, and 13% applied more than 130%. The reported percentages total 101%, likely because of rounding; they describe this Landscape Group, not U.S. households generally. (Water Research Foundation, Residential End Uses of Water, Version 2: Executive Report; Water Research Foundation, REU2016 Erratum)
For this same group, the report estimated that eliminating irrigation above theoretical requirements would reduce average outdoor use by 8,200 gallons per household, or 16%. This is a modeled conservation scenario for the study group, not a measured saving achieved by households. (Water Research Foundation, Residential End Uses of Water, Version 2: Executive Report)
Residential water use statistics: U.S. domestic water supply
Household fixture studies describe end uses in participating homes. USGS domestic water statistics answer a different question: how much water people obtain from self-supplied sources, such as private wells. In 2020, about 17% of households in the conterminous United States had self-supplied water sources. For the lower 48 states, USGS estimated self-supplied domestic withdrawals of about 4,740 million gallons per day, including about 4,073 million gallons per day for indoor use and 667 million gallons per day for outdoor use. These are modeled withdrawal estimates for 2020, not total household consumption from all public and private supplies. (U.S. Geological Survey, “Domestic Self-Supplied Water Use”)