Performance of water distribution systems during intermittent versus continuous water supply

A critical appraisal of selected water distribution networks was made under two modes of operation-intermittent water supply and continuous water supply. The study zones selected in four Indian cities-Ghaziabad, Jaipur, Nagpur, and Panaii-were typical residential areas with metered water supply and were readily amenable to hydraulic isolation from the rest of the area. The study areas included Lohia Nagar in Ghaziabad, Army Welfare Housing Officer's Colony in Jaipur, Shankar Nagar in Nagpur, and Mala Area in Panaji. Preparatory work in the study zones included updating water distribution network plans; installing valves and bulk meters wherever necessary to hydraulically isolate the zone from the rest of the area; and surveying homes to check for stopcocks and water meters and to collect information on household populations and consumers' opinions regarding water supply service. Both water supply modes were studied to collect data on per capita water consumption, pressures at various points in the distribution network, flow rate and variation and total flow into the network, nonrevenue water, water quality, and relevant information for engineering and socioeconomic analysis of the distribution network. Continuous water supply has certain advantages over intermittent water supply. There was an appreciable improvement in nodal pressures and flow patterns in the distribution networks and a decrease in peak factors. Also, microbial quality of the water improved considerably at the consumers' end. However, water consumption and nonrevenue water increased when the mode of supply was switched over from intermittent to continuous, which points to the need for preventive maintenance of distribution systems and proper metering at the consumers' end.