Water efficiency spans household demand, fixtures, leaks, irrigation, commercial buildings and the energy used to heat water. The figures below distinguish observed measurements, program specifications, modeled estimates and case-study outcomes across the United States, with dates and scope stated for each measure.
Key Water Efficiency Statistics
These are the most useful headline figures across household, product, commercial and national water-efficiency data:
- In 2015, U.S. residents used an average of 82 gallons of water per person per day at home.
- Bathrooms accounted for more than 50% of indoor household water use in an EPA estimate for U.S. homes whose survey period was not stated.
- Showering accounted for nearly 17% of residential indoor water use in an EPA estimate with no stated measurement year.
- U.S. showering uses nearly 1.2 trillion gallons annually in an EPA national estimate.
- Residential outdoor water use is nearly 8 billion gallons per day in an EPA estimate for the United States.
- WaterSense-labeled products are at least 20% more water-efficient than standard models while maintaining equal or better performance under the program specification.
- WaterSense toilets use no more than 1.28 gallons per flush under the current EPA calculator assumption.
- Standard showerheads use 2.5 gallons per minute, compared with a WaterSense maximum of 2.0 gallons per minute.
- A WaterSense showerhead saves an average family more than 2,700 gallons per year in an EPA modeled annual-savings estimate.
- The average family can waste 180 gallons per week from household leaks in an EPA estimate.
- Household leaks can waste nearly 900 billion gallons nationally each year in an EPA extrapolation.
- Up to 50% of outdoor water can be lost to wind, evaporation and runoff from inefficient irrigation in an EPA estimate.
- A WaterSense controller can reduce average-home irrigation use by up to 30% in an annual modeled scenario.
- WaterSense and its partners had saved 11.2 trillion gallons cumulatively through the end of 2025 according to the program’s estimate.
- U.S. water use in 2015 was about 322 billion gallons per day, 9% below 2010 across all sectors and withdrawal categories.
- Water heating consumed an average 2,706 kWh of electricity per U.S. household in 2020 according to EIA RECS data reported by the U.S. Department of Energy.
- Replacing older flushometer toilets in a modeled 10-story office with 1,000 occupants could save nearly 1.2 million gallons per year.
- Kennesaw State University saved more than 650,000 gallons in six months after switching dormitory showerheads in a 2014 case study.
Contents
- Household water efficiency statistics and indoor demand
- Fixture water efficiency data: toilets, faucets and showerheads
- Leak, irrigation and behavior water efficiency statistics
- Home water efficiency savings and WaterSense programs
- Commercial water efficiency statistics for buildings
- Water efficiency trends, energy use and national outcomes
- Water efficiency case studies and adoption results
Household Water Efficiency Statistics and Indoor Demand
The U.S. household baseline includes indoor and outdoor demand, and the measures are not interchangeable. USGS reported average total domestic use of 88 gallons per capita per day in 2010 and 82 in 2015, combining public-supply deliveries with self-supplied use; the 2015 home-use figure is not total national withdrawal.
| Household measure | Figure | Period and scope |
|---|---|---|
| Home use per person | 82 gallons per person per day | United States residential use, 2015 |
| Indoor use in bathrooms | More than 50% | EPA estimate; period not stated, U.S. homes |
| Residential indoor use from showers | Nearly 17% | EPA estimate; period not stated, United States |
| Average-family showering | Nearly 40 gallons per day | EPA modeled estimate; period not stated |
Sources: About WaterSense, Showerheads, and Public supply and domestic water use in the United States, 2015.
EPA estimates that U.S. showering uses nearly 1.2 trillion gallons per year, while residential outdoor water use is nearly 8 billion gallons per day. Outdoor use averages more than 30% of household water use and can reach 60% in arid regions, so geography substantially changes the balance between indoor fixtures and irrigation.
At least 40 state water managers expected shortages in some portion of their states under average conditions over the following decade in a 2014 assessment. That is a manager-expectation survey, not an observation that shortages occurred in every state or region.
Fixture Water Efficiency Data: Toilets, Faucets and Showerheads
WaterSense sets product thresholds, while EPA calculators use modeled assumptions for older equipment and household behavior. The following comparison keeps those categories separate.
| Fixture or model | Water-use figure | Measurement type and scope |
|---|---|---|
| Pre-1980 toilet | About 5 gallons per flush | EPA modeled vintage average |
| Toilet installed 1980–1994 | About 3.5 gallons per flush | EPA modeled vintage average |
| Toilet installed after 1994 | About 1.6 gallons per flush | EPA modeled vintage average |
| WaterSense tank-type toilet | No more than 1.28 gallons per flush | Current calculator assumption |
| Standard showerhead | 2.5 gallons per minute | Current EPA comparison |
| WaterSense showerhead | No more than 2.0 gallons per minute | Current specification |
Source: How the WaterSense Calculator Works and Showerheads.
WaterSense-labeled products are at least 20% more water-efficient than standard models while maintaining equal or better performance. WaterSense faucets and aerators are about 30% more efficient than standard faucets, according to EPA’s cited estimate.
EPA’s calculator assumes 5.05 toilet flushes per person per day. That is a behavioral input for savings modeling, not a direct count of every household’s use.
A WaterSense showerhead is modeled to save an average family more than 2,700 gallons of water annually, more than 330 kWh of electricity annually, and more than $70 in annual water and electricity costs. Actual results vary with use, utility rates and the energy source used for water heating.
Replacing all old toilets with WaterSense models is modeled to save an average family 13,000 gallons and $130 in annual water costs. Replacing old bathroom faucets and aerators is estimated to save an average family $250 over the products’ lifetime; both figures are modeled scenarios rather than guaranteed bill outcomes.
Leak, Irrigation and Behavior Water Efficiency Statistics
Leaks and behavior create savings opportunities without requiring the same fixture replacement assumptions. EPA estimates the average family can waste 180 gallons per week from household leaks, equivalent to nearly 9,400 gallons per year in the agency’s annualized estimate, while national household leaks can waste nearly 900 billion gallons each year.
Other household actions in EPA scenarios include:
- Running a full dishwasher only when it is full can save nearly 320 gallons per average family per year, assuming one fewer load per week.
- Turning off the tap while brushing can save 8 gallons per day, depending on tap flow and brushing duration.
- EPA’s twice-daily brushing and five-times-weekly shaving scenario saves nearly 5,700 gallons per person per year.
Outdoor irrigation has a wider range of possible losses. Up to 50% of outdoor water can be lost to wind, evaporation and runoff from inefficient irrigation, while an improperly maintained automatic system can waste up to 25,000 gallons annually per household.
A well-managed irrigation system can reduce household irrigation use by 15%, nearly 7,600 gallons per household annually in an EPA scenario. These are estimates and upper-bound examples, not a randomized national trial.
Home Water Efficiency Savings and WaterSense Programs
Controller upgrades show how the same landscape can produce different modeled outcomes. Replacing a clock-based controller with a WaterSense controller can reduce average-home irrigation use by up to 30% and save up to 15,000 gallons per average home annually, depending on the baseline controller and landscape.
EPA’s full-adoption showerhead scenario estimates that installing a WaterSense showerhead in every U.S. home would save more than 260 billion gallons annually and avoid about $2.5 billion in annual water-heating energy costs. This is a counterfactual national scenario, not observed adoption or observed bill savings.
| WaterSense measure | Modeled or program result | Scope |
|---|---|---|
| WaterSense showerhead | More than 2,700 gallons saved per family per year | Average U.S. family |
| All-home showerhead adoption | More than 260 billion gallons saved annually | United States households |
| All-home showerhead adoption | About $2.5 billion avoided annually | Water-heating energy costs, United States |
| WaterSense program | 11.2 trillion gallons saved cumulatively | Through end of 2025 |
| WaterSense program | $278 billion in cumulative bill savings | Through end of 2025 |
Sources: Showerheads and Accomplishments and History.
WaterSense and its partners attributed 11.2 trillion gallons of cumulative savings and $278 billion in cumulative consumer water and energy-bill savings through the end of 2025. These program totals are estimates based on modeled product savings and rates, not direct metering of every labeled product.
Commercial Water Efficiency Statistics for Buildings
Commercial restroom specifications use a different context from household tank-type toilets. WaterSense flushometer-valve toilets use no more than 1.28 gallons per flush, 20% below the federal 1.6-gallon standard, and the commercial flushometer specification sets a minimum flush volume of 1.0 gallon per flush to support drainline transport.
EPA’s modeled 10-story office with 1,000 occupants illustrates building-scale impact:
- Replacing older flushometer toilets could save nearly 1.2 million gallons per year and nearly $10,000 annually.
- Replacing toilets in the women’s restrooms alone could save nearly 870,000 gallons per year.
- Replacing older flushometer toilets nationwide in commercial facilities could save an estimated 39 billion gallons per year.
Source: Commercial Toilets.
The office figures are scenario estimates tied to occupancy, fixtures, usage and utility assumptions. The national 39-billion-gallon figure is also a counterfactual replacement scenario, so it should not be read as current measured commercial savings.
Water Efficiency Trends, Energy Use and National Outcomes
USGS reported total U.S. water use of about 322 billion gallons per day in 2015, 9% below 2010. This measure covers all sectors and withdrawal categories, so it is broader than household efficiency.
In 2015, about 283 million people received potable water from public-supply facilities, representing about 87% of the U.S. population. About 42.5 million people, or 13%, supplied their own domestic water; these populations should not be combined with fixture-specific household scenarios as if they were the same dataset.
Source: Public supply and domestic water use in the United States, 2015.
Water heating connects water efficiency with household energy demand. EIA RECS data reported by the U.S. Department of Energy show average U.S. household water-heating electricity use of 2,706 kWh in 2020; that figure covers electricity consumption and excludes water-heating energy supplied by non-electric fuels.
Water Efficiency Case Studies and Adoption Results
Case studies show what occurred in named settings, but their results should not be generalized without local context. Kennesaw State University dormitories in Georgia saved more than 650,000 gallons in six months after switching showerheads in a 2014 intervention, reduced water use by about 28%, and saved $6,500 in water bills over the same six-month period.
Source: Shower Better.
Kohler introduced 120 WaterSense-labeled products in 2023: 7 toilets, 70 bathroom faucets, 35 showerheads, hand showers and rain heads, and 8 urinals, bowls or valves. EPA estimated that sales of WaterSense products from Kohler, Sterling and Kallista saved about 91 billion gallons in 2023 and were associated with more than $1.6 billion in water, sewer and energy-bill savings.
Source: WaterSense Awards.
Those named-brand product outcomes were calculated with the WaterSense Partner Savings Calculator rather than direct meter readings. The same EPA award-page summary reports that a participating-home program achieved an average 13% reduction in weekly water consumption versus control homes, but it does not provide the sample size or full study design.
The award-page summary also reports that Kohler trainings reached 7,780 attendees in 2023. Attendance measures outreach scale, not proven behavior change or water savings.