Households in Washington DC, US, are the biggest consumers of water compared to 169 other world cities, while households in Jinja, Uganda, use the least amount of water, a new report shows.

The International Statistics for Water Services 2016 study, compiled by the International Water Association (IWA), and published during the World Water Congress in Brisbane, (October 9 to 14, 2016), collates data from 40 countries and 170 cities worldwide.

As well as data on water consumption, the report looks at levels of water abstraction worldwide, charges levied for drinking water, and regulatory arrangements.

After Washington (631 litres a day), households in New York, US (476 litres a day), and Vancouver, Canada (352 litres a day), are the second and third highest consumers of water. At the other end of the scale, homes in the city of Entebbe, Uganda (38 litres a day), are the third lowest users, and North-Western Water and Sewerage Company of Zambia (34 litres a day), is the second smallest consumer, compared to Jinja (28 litres a day).

Western Europe emerges as the most expensive region for water charges in 2015, with the top 10 most expensive cities for water dominated by those in Scotland, UK, as well as Belgium, Denmark, and Switzerland; Vancouver, Canada, also features in the top 10 with the third highest charge.

The IWA highlights several other trends: no single tariff structure is trending worldwide, with a mixture of fixed charges, variable charges, and environmental charges in use; water remains subsidised in many countries and cities; and “pricing is a useful tool for reducing water consumption in times of water scarcity, keeping in mind that the price elasticity for potable water is, in general very low or even zero”.

Ed Smeets, chair of the IWA specialist group of statistics and economics, said: “When we look at pricing trends, we are seeing a divergence of the VAT charges on water and wastewater. A low VAT for potable water, which is a human right, and a higher VAT for wastewater collection and treatment, which is not a human right. One of water managements’ goals should be to make the total cost and recovery of water visible, so that we as customers will have a better understanding of our own responsibilities to optimise usage. By presenting tariff structures in a transparent way, we hope that this report provides some insight to water managers.”