OECD Observer
Water quality and conservation

Although agriculture and industry are the thirstiest of all water consumers, household water use accounts for some 10-30% of total consumption in developed countries. As governments develop strategies to promote water conservation, an OECD survey of households conducted in 2008 offers insight into what really works. Based on some 10,000 responses across 10 countries, the answer is as clear as what comes out of the tap: having to pay for water encourages water-saving behaviour and investment in water-saving appliances, thus reducing consumption.

People’s perceptions of tap water quality is a good place to start. The survey finds that two thirds of the respondent households drink tap water regularly. Moreover, the greatest satisfaction with the quality of tap water is reported in the densely populated Netherlands, though Swedes and Norwegians also report being highly satisfied with the quality of their tap water, whereas Canadians report lower satisfaction (graph 1). Where satisfaction was low, in some countries, such as France, this largely reflected concerns about taste, whereas in Korea and Mexico potential health impacts were the main concern. How much the subjective opinions in the survey relate to objective criteria of water quality demands more research.

People who are dissatisfied with their tap water can either demand improvements in public water services and/or switch to bottled water for drinking. On the one hand, households were willing to pay an average of €14 more per year for further improvements to public tap water quality. On the other hand, people who choose to buy bottled water do so for health reasons, though also for reasons of taste and because they can afford it (graph 2). They are also more likely to own a car–the easiest way to bring the bottles back home. But concern about plastic waste puts people off bottled water, the survey suggests.

The survey finds that water charges affect consumption: households that are charged according to how much water they use consume an average of 25% less water than those households that either pay a flat fee or have free access to water services. People who pay by volume of water used also tend to be more likely to conserve water by turning off the tap while brushing their teeth, collecting rainwater or recycling wastewater. They are also more likely to have water-efficient devices, such as washing machines that use less water, dual-flush toilets or water-flow restrictors (see graph 3). Australians, who face severe water scarcity in their country, report particularly high levels of investment in such equipment.

More survey results are available at www.oecd.org/environment/households. For more information, contact Yse.Serret@oecd.org or Nick.Johnstone@oecd.org 

©OECD Observer No 278 March 2010