Modelling Intermittent Water Supply Systems with EPANET

Abstract

Modeling rural networks and intermittent water supply systems is a challenging task because these systems are not fully pressurized pipeline networks but networks with very low pressures, with restricted water supply hours per day, and with thousands of ferrule points and roof tank connections. The alternate emptying and refilling of water pipelines makes it problematic to apply standard EPANET based hydraulic models because of low pressures and pipes without water. EPANET source code was adjusted to allow for modeling pressure dependent demands, for dealing with low pressure and “dry pipe” situations. A configurable tool was developed for incorporating roof tanks into the water supply analysis and for better formulation and schematization of the system hydraulics. Two cases studies, water distribution model of Shillong in India and detailed water distribution model of Dhaka in Bangladesh are used to illustrate the practical use of this approach. The experience from using and adjusting the EPANET engine for the modeling of intermittent water supply systems is discussed in this paper.