Small decisions made in the shower, from how often you wash your hair to your water usage habits while showering, can significantly influence household water consumption. Recent research highlights this impact, revealing that shower routines, such as multiple shampoo applications, correlate more strongly with longer showers than factors like age, gender, or household characteristics.
Published in the Journal of Environmental Management, the study positions showers as the largest contributor to indoor water use, comprising 25 to 45 percent of household consumption. Researchers observed behaviors in 319 German households using smart sensors in bathrooms, recording 8,550 shower events over 40 days. These sensors tracked shower duration, pauses in water flow, and environmental conditions, complemented by surveys gathering demographic data, hair characteristics, and product usage.
One clear pattern emerged regarding shampoo application: showers with two or more shampoo uses lasted approximately 27 percent longer than those with a single application. Study co-author Dr. Pablo Pereira-Doel emphasized the influence of shower actions on water use rather than identity or location. Routine actions such as double shampoo applications or running water while lathering profoundly extend shower durations.
The study found showers with frequent water-flow interruptions often lasted longer. For example, participants who paused the water three or more times spent 20 percent longer showering than those who did not pause the flow. Compared to individuals who paused water only once, the total shower duration was 28 percent longer. Age-related differences also emerged, with younger and middle-aged adults generally spending more time in the shower than those over 50.
Water hardness presented another factor. Regions with soft water experienced showers lasting around 23 percent longer than those with hard water. This potentially results from softer water creating richer lather and offering a more comfortable washing experience.
The average American shower consumes about eight minutes and roughly 16 gallons of water, according to the EPA. While efforts to reduce household water demand commonly focus on efficient showerheads and economic measures, researchers argue examining shower behaviors may offer more effective strategies.
Potential strategies include promoting single shampoo applications and encouraging you to turn off the water while lathering. They propose behavioral nudges, feedback devices, and product design modifications to lower water usage without compromising comfort. Pereira-Doel advocates for solutions aligned with habits rather than opposing them, suggesting nudges, smart feedback devices, and better design as avenues to decrease water use without sacrificing comfort.
The study concludes that minor shower actions can significantly impact water use. While technological conservation strategies remain essential, the researchers underscore the importance of understanding daily habits to reduce household consumption effectively.
Reference: David Morizet et al, Event-level modelling of showering behaviour in German households: Triangulating smart-meter, in-situ survey and contextual public data, Journal of Environmental Management (2026). DOI: 10.1016/j.jenvman.2026.130596
Contact Newsweek editors on this story: Kara Dolman and Emma Lee-Sang
Leave a Reply