How Much Water Do Americans Use For Toilets And Showers?

Flume Household Water Use Index Reveals Increased Efficiency Levels

San Luis Obispo, CA /PRNewswire/ - Flume, the company that brings connectivity and intelligence to household water usage, today released the quarterly results for the Flume Household Water Use Index, the leading measure of U.S. household water use. For the first time ever the Flume Index includes fixture level data on toilets and showers, identifying the current efficiency level of fixtures across America from the largest data set of this type ever assembled. The Flume Household Water Use Index is based on data from tens of thousands of Flume devices that are installed on household water meters across the nation. Flume water use data summaries are reported quarterly.

National Indoor Per Capita Water Use
Indoor Household Water Use averaged 44.4 Gallons per Capita per Day (GPCD) in Q3 2021.

In Q3 2021 national average indoor water use dropped below the levels measured before the pandemic, following a period of higher indoor water use during most of 2020 due to COVID-19 restrictions. On a national scale, the lingering impacts of increased indoor use appear to be over. Additional indoor efficiency remains as houses equipped with efficient fixtures and appliances can use 30 - 35 GPCD on average.

Indoor Per Capita Use by Metro Area
The Flume Index also measured Indoor per capita use for the 15 most populous Metropolitan Statistical Areas (MSA) in the US for Q3 2021. The San Francisco MSA was the most efficient metro area during Q3, with an average indoor use of 39.5 GPCD. The Riverside MSA had the highest indoor use per capita in Q3 2021 with an average of 51.6 GPCD.

National Outdoor Household Water Use
Outdoor Household Water Use averaged 284.1 gallons per household per day (GPHD) in Q3 2021. The data showed a decrease of 30% from Q3 2020, as the northeast saw a wetter than normal summer, and drought restrictions were imposed across the west and the south.

Efficiency Level of American Toilets and Showers
The Index analyzed the September 2021 water use for every Flume household in America using signal processing approaches with machine learning. The resulting data set of showers and toilet flushes is more than ten times larger than the two previous national residential water use studies combined, published by the Water Research Foundation in 1999 and 2016.

The average toilet flush volume was 2.2 gallons per flush based on an analysis of more than 5.9 million flushes across tens of thousands of households. Toilets were flushed an average of 5.5 times per person per day. The average shower used 14.3 gallons, lasted 7.4 minutes and was taken at an average flow rate of 2.0 gallons per minute. These numbers show the continued efficiency improvement in toilets and showers since 1999 and 2016 levels.

"The ability to disaggregate individual end uses enables a deep understanding of where water is used and where it can be most effectively conserved," said Peter Mayer, P.E., Principal of WaterDM, an expert consultant to the water industry for more than 25 years. "These results show some efficiency potential remains in reducing toilet flush volumes, but that many showers are already taken at efficient flow levels so there are less potential savings there."

For More Information
For more information about how Flume collects and analyzes water use data, and for detailed graphs with additional insights, please visit the interactive Flume Household Water Use Index Dashboard.

About Flume
Inspired by California's record drought, Flume empowers homeowners to better understand their usage and conserve water. By providing real-time water use information, Flume protects the home, puts the power of water consumption and conservation in the customer's hands, and improves the relationship with our most precious resource. The Flume Smart Water System consists of an easy-to-install sensor that adapts to most existing home water meters, which communicates water use to the homeowner in real-time. To date, Flume has tens of thousands of devices installed across the United States. Learn more at www.flumewater.com.