Beyond the Water Flow Rate: Water Pressure and Timer Impact Shower Efficiency, 2021-2022

England is projected to face a water supply shortfall of 4 billion litres daily by 2050 due to population growth, water pollution, and increasing climate-driven droughts and flooding. The Environment Act 2021 mandates significant water usage reductions, targeting a decrease to 110 litres per person/day for households and a 15% cut for businesses. Enhancing water efficiency in showers is crucial, given their high water consumption, energy use and associated carbon emissions.Water consumption in 290 showers was covertly monitored for 39 weeks, capturing 86,421 showering events. Increased water pressure was strongly associated with reduced water use - an effect that might be amplified even further by installing timers to inform users of their shower duration.