Geospatial modeling of water supply distribution system: A case study of Dehradun city, India

Water utilities form the core part of any urban infrastructure. A spatial database of water distribution system (WDS) for Dehradun city has been created in a geographic information system (GIS) environment, while drawing data inputs from diverse sources and water supply-demand gap analysis has been performed. Environmental Protection Agency Network (EPANET, 2.0) has been used to analyze the WDS to explore its reliability in current and future scenarios. Mapping of the existing 564 km long distribution network revealed that more than three-quarters of the system has outdated water pipelines. An accuracy of 93% for pipe diameter estimation has been obtained upon validation by ground penetrating radar (GPR) survey. Water supply-demand gap analysis confirmed that although Dehradun city has surplus supply, it suffers from scarcity, mainly due to the unsatisfactory condition of the existing WDS. Twenty-seven percent of the existing pipes are smaller than the prescribed standards; there is an undesirable practice of direct pumping of water from tube wells into the network and storage tanks are required for at least 29 locations in the network. A 24-hour extended period EPANET simulation helped to identify the areas where water supply network experienced very low or negative pressure.