Distribution Network Assessment using EPANET for Intermittent and Continuous Water Supply

Drawbacks of intermittent water supply system and inability to shift to continuous supply mode is the main challenge in developing countries. The suitability of the infrastructure laid over past two to three decades to meet the 24/7 demand of todays population is the issue for many water mangers. The present study addresses this issue using EPANET software for a pilot study area in Nagpur city, India. GIS maps, field survey data, remote sensing data and in-situ measurements of pressure and water quality are used in model simulation study. Total 96 artificial reservoirs are inserted into the network which replicate the end-user practices of excess water withdrawal. Reservoirs are assumed connected to damand nodes with equivalent diameter pipes for intermittent supply simulation. For continuous supply, demand multipliers are derived using Monte Carlo simulation. Bulk decay coefficient 0.17 day(-1) for residual chlorine is used in water quality simulation. Simulation scenario of intermittency indicates existing network is not suitable to maintain desired headloss, and pressure in most of the pipes is very low (< 1 m). Water age and water quality problems reveal that rehabilitation of distribution mains and critical pipes in the central part is primarily important before implementing 24/7 water supply scheme in the study area.