Customers' water use underestimated by utility firms and government, says study

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Utility companies and government in the UK are underestimating how much water customers use, a new study suggests.

An investigation into the water consumption habits of more than 8,000 students in university halls of residence over the past four years has revealed that students are using as much as 180 litres of water every day - 30 litres higher than the widely-used industry estimate of 150 litres per day.

The finding was made during a study which has seen student accommodation at the University of the West of England used to explore the complexities of domestic water consumption.

Metering systems have been installed at the university's Frenchay campus, allowing academics to receive water use data on an almost real-time basis.

Sophisticated data segmentation techniques allow the researchers to explore particular water using behaviours, like dish-washing, without revealing personal information.

Professor Chad Staddon, who is leading the study, was initially surprised by the average per person per day water use figure discovered in the project.

"The figure was higher than industry expectations despite our students living in accommodation which does not have associated green spaces or driveways, so water is not being consumed on gardening or washing cars," he said.

"But there is a ready explanation - because the students live on campus and often prefer to study in their flats, water use does not fall off in the day as much as might be expected in more 'normal' residential communities with higher daytime vacancy rates."

Fixture inefficiencies, such as leaky loos, are also part of the underlying cause of higher consumption.

"Our figures could be a better gauge of total per person per day use than the domestic measure currently used by water industry," said Prof Staddon.

"Our measure is more indicative of total daily use because most of the students use all their water in one place - at home."

The research is also exploring differences in water use by gender and student origin.

Female students tend to use more water than men - a variation which can be explained by the extra water needed to wash longer hair - and that UK national students consumed less water than their international counterparts.

The researchers thought this was linked to the greater propensity of British students to go home at weekends and holidays.

Another element of the research is focused on testing the effectiveness of interventions aimed at reducing water use.

Prof Staddon said: "The results so far suggest that hard measures simply reinforce lower water consumption without really affecting overall behaviour - those who want or need to consume more water usually find ways to do so, such as simply showering for longer.

"During this past academic year, we have been exploring the effects of water pressure on water consumption, based on the insight that pressure is sometimes as important as flow for end users.

"Research to date suggests students haven't noticed the pressure changes at all, and that water is being saved, but we will have to wait until later in 2017 for the full results."