Estimating scenarios for domestic water demand under drought conditions in England and Wales

This paper presents preliminary results from the development of IMPETUS model, a domestic water demand microsimulation model which was developed to estimate the results of a range of scenarios of domestic demand under drought conditions. The model is intended to enable water resource management practitioners to assess the likely impact of potential interventions in particular catchment areas. It has been designed to be driven by seasonal catchment level forecasts of potential hydrological droughts based on innovative climate and groundwater models. The current version of the model is driven by reconstructed historical drought data for the Colne catchment in the East of England from 1995 to 2014. This provides a framework of five drought phases (Normal, Developing, Drought, Severe and Recovering) which are mapped to policy driven interventions such as increased provision of water efficiency technologies and temporary water-use bans. The model uses UK Census 2011 data to develop a synthetic household population that matches the socio-demographics of the catchment and it microsimulates (at the household level) the consequences of water efficiency interventions retrospectively (1995–2014). Demand estimates for reconstructed drought histories demonstrate that the model is able to adequately estimate end-use water consumption. Also, the potential value of the model in supporting cost-benefit analysis of specific interventions is illustrated. We conclude by discussing future directions for the work.