This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Find out more here

FEATURE21 May 2018

BE 360: stopping our taps running dry

Behavioural economics Energy Europe Latin America Opinion UK

Water is our most precious resource but often misused and taken for granted. But as The Behavioural Architects’ Crawford Hollingworth and Liz Barker explain, using behavioural science can help reduce our water consumption.

Around four billion people, almost two thirds of the world’s population, experience severe water scarcity for at least one month of the year, and half a billion live with constant water scarcity.[ 1 ]

In fact, since 2012, the World Economic Forum has put water supply crises among its top three global risks in terms of impact, putting it on a par with weapons of mass destruction, climate change and the outbreak of infectious disease.

Source: UN World Water Development Report, 2012[ 2 ]

The problem is not looking like it will abate. The UN forecast in 2014 that two thirds of the world’s population will be living in water stressed areas by 2025. By 2050, demand for water will increase by around 55%, driven by a 60% global increase in food demand, together with a 400% increase in demand for water for manufacturing in developed countries.[ 3 ]

The World Bank also forecasts that water availability in cities could fall by as much as two thirds by 2050, because of climate change and competition from energy generation and agriculture.[ 4 ]

Most affected currently are households, industries and farmers in Mexico, the western US, northern and southern Africa, southern Europe, the Middle East, India, China, and Australia, where already they regularly experience water shortages. Recently, Cape Town only narrowly averted ‘Day zero’ – the day when taps would be turned off for its millions of residents, forcing them to queue at military-guarded standpipes for a 25 litre per day ration – by intricate and cautious management of its supplies.[ 5 ] But other regions face long term risk too.

So, while a significant proportion of the current water supply is used by agriculture, we individuals and households still need to take on some of the burden and manage our water more carefully. And it has inspired a number of organisations to develop and test innovative approaches to get households using less water.

What might be preventing us from cutting our water use?

Qualitative and quantitative research by these organisations have identified several barriers preventing households from better managing water:

  • A major one is that we use it habitually, often without really being aware of the actions that trigger us to use it. We turn on the taps, run the shower and flush the toilet on autopilot. Research by Michelle Lute, Shahzeen Attari and Steven Sherman found that 80% of people feel flushing the toilet is something they do habitually, driven by having been taught to do so at a young age.[ 6 ]
  • Utilities companies don’t make it easy for people to understand their water use, with no clear reference points (known as anchors by behavioural scientists) and consequently customers have a poor understanding of how much water they use. Water bills are typically reported in cubic metres. Yet research in Costa Rica by Ideas42 and the World Bank found that people find it hard to visualise cubic metres of water and lacked intuition into whether an amount billed was large or small.
  • Billing is also infrequent, meaning that there are large time lags in feedback. Timely feedback on an activity or task can help to motivate us, increasing our engagement and ultimately, helping us achieve our goal. Behaviour is often more malleable when we receive real time feedback, rather than months after the event because it allows us to change our behaviour immediately without any delay.
  • Also, because the bill comes as a lump sum, it’s hard to understand what changes in water use might have the most effect and people struggle to outline specific steps they would take to reduce their water use. Some people mistakenly believe that changes such as turning off the tap while brushing their teeth will make a difference. While every little effort helps, it’s showering, bathing and flushing the toilet that use the bulk of our water (see diagram).


Source: Thames Water

  • Another barrier is the relatively low cost of water compared with other bills, meaning that any potential savings often don’t feel worth the effort and more like pocket money, especially for more affluent households. People anchor or compare their relatively small water bill to the bigger bills such as electricity and conclude that potential savings on their water bill are negligible. Research by ETH Zurich found that households are often not responsive to price increases because water is relatively cheap and seen as a necessity.
  • Finally, we also often misperceive others’ water use. It’s easy to notice outdoor water-heavy activities such as neighbours washing their cars or watering their garden, but we may be less aware of others’ indoor water use. Since we are often guided by social norms – by what we see others doing – we may feel ‘licensed’ to continue using water as we always have – an ‘if no-one else is making an effort why should I change’ attitude.

Given these problems and barriers to change, what steps can be taken to help people reduce their water consumption?

Saving in the shower

A major large-scale study[ 7 ] run by ETH Zurich has found that providing people with real-time behavioural feedback on how much water they are using relative to the ideal might be one solution. First piloted in Switzerland in 2012, this approach has now been trialled in the Netherlands, Germany, South Korea and Singapore with considerable success.

This trial targeted showers only, recognising that showering accounts for more than 80% of hot water demand and a good chunk of overall water demand. Behavioural scientists have also learnt that specific goals are often easier for people to work towards than broader ones. Since people are often unsure what action exactly to take to save water, focusing on a single objective could lead to bigger impacts.

Almost 700 households received smart shower meters, which could be easily installed on a hand-held shower at eye level and requires no battery as it was powered by the water flow. The meter displayed how much water and energy had been used since the shower was turned on –  giving people instant and salient use feedback which behavioural scientists have found effective in motivating people to change behaviour. As they watch the litres used rising, they might be motivated to stop singing and hurry their shower along.

The meter display also showed an ingenious animation of a polar bear on an ice flow. If someone took a very long shower, the ice flow began to shrink and melt and eventually the entire animation disappeared. This initiative really made salient the connection between high energy consumption (to heat the water), carbon footprint and climate change.

One group were also given the same information on their previous shower as a reference point. Another group also received feedback on their energy efficiency rating. All this information helped to give feedback at the right time for people to act. Verena Tiefenbeck who helped run the study said: “We provided the information in real time so that people saw that feedback as they took their showers, while they could still do something about it.”

The impact over the two-month trial was significant: people cut their shower time by around 20% on average, reducing water consumption by 21%. This also cut energy consumption by 22%, resulting in yearly savings of 452 kWh for a two-person household or roughly 12-13% of the average European household’s electricity bill.[ 8 ]

To put that in perspective, a fridge freezer uses around 427 kWh per year and a plasma TV 658 kWh. A previous study by ETH Zurich testing the impact of electricity smart meters found only an 86 kWh reduction – five times less than the shower study and showing that a narrower focus can reap more gains than broader targeting.

The device was inexpensive, paying for itself within nine months from savings on water and electricity bills. While the initial pilot ran for only two months, later studies have typically run for three to six months and found no drop off in impact. The meters have also been installed in nine Swiss hotels and have received a positive response with the savings almost as big as those in households.

A similar study run in Singapore for 16 months found the same level of impact. While the shower meters still gave real time feedback, the intervention differed slightly in that households were given varying water conservation targets of 10, 15, 20, 25 or 35 litres. They found the most effective target was 15 litres – a moderate volume target – where people used 3.9 litres less water an average.[ 9 ]

A simple nudge to reduce water

Other organisations have had success with even simpler initiatives, simply changing the communications received from water companies to nudge reductions in water consumption. In 2014, ideas42 and the World Bank partnered for a project in Belen, Costa Rica.[ 10 ] Costa Rica is already being affected by periodic water shortages, yet general awareness campaigns run by the municipal authorities and raising rates by 70% had not had an impact.

Qualitative research revealed that providing people with comparative points of reference may help to influence their water use as well as helping people better understand what behaviours could help reduce consumption. So, one solution was developing stickers to go onto bills informing households about how their use compared with either their neighbourhood (group 1 ) or the city (group 2 ).

One had a happy face to congratulate a household with consumption below the median and a second had a sad face if use was above. From a behavioural science point of view, we know that people generally want to fit in and conform with what others are doing, so knowing that we are using more water than others around us could be enough to prompt us to act.

A second initiative was to send out postcards to all households showing:

  • average monthly consumption in the area, providing households with a much-needed reference point to compare their own use to
  • a space to record their own use
  • a space to set a target to reduce their consumption for the month ahead (group 3 ). Setting a specific target can make us feel more committed to achieving that goal. Writing it down (especially in public) can escalate this even further
  • six specific ways to save water, such as using less water in the garden, showering for less time, fixing leaky pipes and sweeping the sidewalk rather than hosing it down. Identifying concrete steps to take to meet a goal or target can make it feel easier to achieve.

Overall, there were 5,600 households involved in the trial, split into the three test groups plus a control group who received none of the initiatives. By analysing households’ water usage over the next two months and comparing it with average consumption rates for those months in the previous year, the research team could deduce if any of the tests had worked.

The neighbourhood stickers worked; households receiving those typically cut their water consumption by between 3.7% and 5.6%. The postcard also helped with reductions between 3.4% and 5.6%. (The citywide stickers did have an impact too, but a smaller one.)

This was a relatively low-cost solution amounting to just $400 worth of stickers – a valuable approach for low income or developing countries that may not have resource for technology based or more complex solutions.


[ 1 ] World Finance, The threat of water scarcity looms large, Oct 2017;

[ 2 ]

[ 3 ] UN World Water Development Report 2017

[ 4 ] WEF Global Risks Report 2017; World Bank. 2016. High and Dry: Climate Change, Water, and the Economy. Washington, DC: World Bank;

[ 5 ] FT, South Africa: How Cape Town beat the drought, May 2018

[ 6 ] Don’t rush to flush’

[ 7 ]

[ 8 ] Based on the European household consumption average of 3600 kWh. UK households typically consume slightly more than this – 3800 kWh. Source: and Ovo

[ 9 ]

[ 10 ] and

1 Comment

4 weeks ago

Liz, greazt article :) However, you forgot Hydrao the world's first smart shower! We are currently trialing our solutions with Thames Water and United Utilities and will be piloting with two major California universities before the year is out. We will start shipping Hydrao Aloé (=V3) in the coming days to honor our tender win with PUB in Singapore end-2017. Cheers, Eric

Like Report