UK water regulator Ofwat has advised Muslims to use less water during wudu, the ritual ablution, as part of a wider water-saving initiative. The advice was issued through the Ofwat-funded Water Efficiency in Faith and Diverse Communities programme. A pilot project in Cambridge encouraged worshippers to use one litre of water rather than leaving taps running, and recommended wider promotion through Islamic television channels.

Ofwat said some people use up to about 12 litres of water across five daily ablutions. It estimated that using a one-litre bottle could save up to 55 litres per person each day. The Cambridge pilot reportedly saved around 5,900 litres of water daily. Water companies were also told to communicate the campaign carefully so that Muslims would not be portrayed as responsible for water waste.

The initiative has drawn criticism from some UK Muslims, who questioned whether religious practice should be singled out for conservation measures. They argued that leaks and infrastructure problems should receive priority. Citing Greenpeace UK research published in July, the report said leaking pipes waste about 2.87 billion litres daily in England and Wales. Ofwat said the project was not intended to change religious practices and ended in April 2025.