Enhancing water sustainability in ablution (wudu): lessons from Prophet Muhammad’s (صلى الله عليه وسلم) wudu practice and the role of water-efficient aerators

Abstract This paper presents Water-Efficient Aerators (WEAs) as a practical, scalable, and cost-effective solution for reducing freshwater consumption during ablution. These aerators, available globally (US, EU, Australia), feature low flow rates (1.0–1.5 GPM) and achieve high water efficiency (30–55%) at an affordable cost ($6–12 USD). Endorsed by the Environmental Protection Agency’s (EPA) WaterSense program, the proposed WEAs have undergone certified laboratory testing to ensure performance under varying pressure conditions and offer a retrofit-friendly, maintenance-free solution compatible with most standard faucets. Rather than relying on experimental trials, this study focuses on broad implementation using a mathematical model specifically developed for ablution, based on empirical benchmarks such as an average ablution duration of 1.04 min from prior field studies. To ensure credibility and practical relevance, the reliability of mathematical model is supported through scenario-based validation with prior experimental studies for water consumption using range of tap types and time utilized for ablution. The model assumes full compliance with daily prayer requirements to estimate maximum potential savings, while remaining adaptable to user-specific compliance levels and practices. Findings demonstrate that combining WEAs with water-saving behaviors particularly the practice of turning off the tap during ablution can substantially enhance conservation outcomes, reducing per-person water use from 2.29 to 0.54 gallons (8.66 to 2 L), enabling up to 76% reduction in freshwater consumption. This aligns closely with the sustainable water use practiced by Prophet Muhammad (صلى الله عليه وسلم), who performed ablution with approximately 775 ml (0.2 gallons), serving as an exemplary benchmark for efficient water use till to date. The proposed solution contributes to Sustainable Development Goals (6, 12, and 13), underlining the synergistic impact of both technological interventions and behavioral change in achieving water sustainability.