All water companies in England and Wales have a statutory duty to prepare water resources management plans every five years, and these must include a forecast of the demand for water arising from households in their region.
The demand for water in some parts of the Affinity Water region are expected to exceed the available future supplies. In addition, household water demand is particularly challenging to forecast as it is affected by a wide range of factors. The guidance for producing these forecasts had recently been updated to allow more sophisticated modelling approaches – such as multiple linear regression (MLR) – to be used by water companies.
Artesia had been working on a range of demand and leakage projects for Affinity Water for several years and had also produced the updated guidance on demand modelling approaches. This meant we were able to work closely with Affinity to develop a demand model of their household water use that accounted for their extensive domestic metering plans, made use of a range of socio-demographic and property explanatory factors, and could be used to forecast water use into the future.
This resulted in a new household consumption forecast which Affinity Water were able to use in their WRMP19 for all their households including their social tariff households and reclassified non-households. In particular, the new model was validated in a way that was not possible with previous approaches and as a result Affinity Water had greater confidence in the performance of the new model. The model was also linked with their in-house tools to produce the outputs required by the Environment Agency.