Reassessing the social equity objective of currently popular water tariffs

There have been mixed opinions on the widely employed increasing block tariff (IBT) scheme and its efficiency in maintaining water equality. This is the first study providing empirical evidence to evaluate water (in)equality under the current scheme and compare it with other hypothesized ones.
Using a 2014 survey of more than 1700 households in Wallonia, social equity was evaluated based on average water price, cross-subsidy, and the ratio of water bill to income. Comparisons were carried out among different income groups under several tariff schemes.
Our results showed that the current water pricing in Wallonia is regressive, with poorer households subsidizing the richer ones. One possible remedy for this situation is reducing the fixed subscription fee (FSF) share within the tariff. Comparison among different tariffs showed that IBT-con with a reasonable FSF is the most progressive scheme for Wallonia and potentially other regions in the developed world.