New Study Shows Residential Water Use Has Fallen More Than 44% Since 1999
Key Highlights
- Single-family indoor water use has dropped 44.4% since 1999, according to a new WRF study
- High-efficiency toilets, faucets and clothes washers continue to drive major water savings
- The report includes the first comprehensive analysis of multi-family residential water use
DENVER, CO — The Water Research Foundation (WRF) has released the 2026 Residential End Uses of Water, Version 3: A Single-Family and Multi-Family Study, providing an updated look at residential water use trends across North America and documenting three decades of gains in water efficiency.
The latest report builds on WRF’s landmark studies conducted in 1999 and 2016, creating a 30-year benchmark for understanding how residential water use has changed over time. The findings show that improvements in plumbing fixtures, appliances, standards and conservation efforts have significantly reduced indoor water consumption.
Indoor Water Use Continues To Decline
As the largest water-using customer segment in North America, the residential sector plays a major role in overall water demand. According to the study, average indoor water use in single-family homes declined 44.4%, falling from 69.3 gallons per capita per day (GPCD) in 1999 to 38.5 GPCD in 2026.
Reductions were recorded across every indoor water-use category, with the largest decreases occurring in clothes washers, toilets and faucets.
For the first time, the study also analyzed multi-family housing. Researchers found that indoor water use in small, individually metered multi-family buildings containing two to six units averaged 39.8 GPCD.
Plumbing Fixtures And Appliances Drive Savings
The report attributes much of the decline in residential water use to continued improvements in the efficiency of plumbing fixtures and household appliances.
Clothes washers accounted for some of the largest gains, with evolving federal energy standards contributing to a 67.6% reduction in per-capita water use since 1999, equivalent to roughly 10 GPCD. Toilet efficiency also improved substantially, with average flush volumes declining to 1.84 gallons in 2026, a 46.6% reduction compared to 1999.
“The primary reason for the changes in indoor use measured across these three studies is the installation and use of water efficient fixtures and appliances,” said Peter Mayer, Principal Engineer at WaterDM and lead author of all three Residential End Uses of Water studies. “National plumbing codes and energy standards have improved efficiency without requiring people to change their water use behaviors at home much, if at all.”
Expanded Research Provides New Insights
The 2026 study incorporates data from 52 participating utilities across the United States and Canada. Researchers also analyzed high-resolution water-use data collected from more than 69,000 single-family homes and 1,000 multi-family residences by lead research contractor Flume Inc.
“The Residential End Uses of Water studies have been some of the most downloaded and cited studies conducted by The Water Research Foundation,” said Kenan Ozekin, Chief Research Officer for The Water Research Foundation. “These studies have helped utilities, planners, private industry, and more, offering improved understanding of where and how water is used in residential settings using basic customer billing data together with innovative high-resolution measurement techniques.”
New Tools Support Future Research
In addition to expanding the number and diversity of study sites, the latest report introduces the first comprehensive analysis of multi-family water use and provides new information on regional similarities and differences.
Project deliverables include a summary report, a comprehensive technical report, an interactive online data dashboard that allows users to explore and visualize study findings, and an educational dataset designed to support future research and analysis.
To learn more visit www.waterrf.org.