A new study has found that specific shower habits—particularly shampoo use—significantly increase household water consumption, accounting for up to 45% of indoor water use.
Researchers from the University of Surrey and other institutions analyzed 8,550 shower events across 319 German households over 40 days, using smart sensors to track shower duration, water pauses, and environmental conditions. The findings reveal that applying shampoo twice or more extends shower time by 27%, while pausing the water flow while lathering reduces overall consumption.
The study, published in the Journal of Environmental Management, highlights that behavioral choices inside the shower—rather than demographic factors—are the primary drivers of water waste. Dr. Pablo Pereira-Doel, a co-author and fellow at the University of Surrey’s Institute for Sustainability, stated: “What matters most is what you actually do in the shower. Small routines such as applying shampoo twice or letting the water run while lathering can extend shower time far more than people realize.”
Key Findings
The research identified several habits linked to longer showers and higher water usage:
- Multiple shampoo applications increased shower duration by 27%.
- Pausing water flow three or more times during a shower extended duration by 20%.
- Letting water run while lathering contributed to prolonged shower times.
On average, participants spent 4 minutes and 48 seconds in the shower, with 64% keeping showers under five minutes. However, 14% of showers lasted longer than eight minutes, consuming disproportionate amounts of water.
Broader Implications
Showers are the largest contributor to indoor water use, accounting for 25% to 45% of household consumption. The study suggests that behavioral adjustments, such as single, efficient pauses while lathering, could substantially reduce water waste without requiring costly infrastructure like water-saving showerheads.
The researchers emphasize that individual habits, rather than household characteristics, are the most critical factor in water conservation. By modifying routines, households could contribute to broader efforts to address water shortages, particularly in regions facing supply challenges.
Expert Recommendations
The study recommends one deliberate pause during showering to lather shampoo, which could reduce water consumption without sacrificing cleanliness. The authors argue that changing everyday habits may be as effective as technological solutions in mitigating water scarcity.