6.There are two principal ways in which water consumers are charged by water companies. Most are charged on the basis of an unmeasured charge, which is usually based on the rateable value of the property. Others are charged by reference to volume, as measured by a water meter. Different water companies have different policies relating to water metering (e.g. whether they offered meter installation free of charge). The charges made by a water company for water and sewerage are set out in the company’s charging scheme, and most domestic customers are charged on this basis. Some people are charged on the basis of an agreement with the water company.
Background English and Welsh Provisions Water Charging in England and Wales