Hydraulic and Water Quality Modelling of Water Distribution Networks Using EPANET Software

Abstract

In this study, hydraulic analysis of two water distribution networks was carried out using EPANET 2.0 software developed by the US Environmental Protection Agency. The study networks are: a hypothetical 65-pipe water distribution network that had been solved by the Linear Theory method; and an existing water distribution network serving the University of Benin Ekehuan campus, for which hydraulic analysis and study for the system improvement had been previously carried out using WaterCAD software. This present study was therefore undertaken to investigate EPANET’s capability in executing hydraulic analysis and deploying it for water quality simulation studies of the campus’ water distribution system, which was not part of the scope of the previous study. The hydraulic analysis results showed that the average of deviations from solved values for total head, pressure head, and flow are 4.23%, 7.69%, and 7.15% respectively, which falls within an acceptable range. Results from the water quality analysis study in which water age and optimum residual chlorine dosage required were used as surrogates for water quality indicate that the existing water distribution network of the campus has a water age and optimum residual chlorine of 1.68 hours and 0.220mg/L respectively, while same for the proposed improved water distribution network of the campus are 5.56 hours and 0.255mg/L respectively. Expectedly, the water age and optimum residual chlorine of the improved network are higher than those of the existing network, as the pipe sizes and storage capacity in the improved network are larger to serve the increased future population of the ultimate design period. Even at that, the obtained values are within acceptable limits prescribed by the Nigerian Standard for Drinking Water Quality (NSDWQ) guidelines. Hence, it is concluded that EPANET and WaterCAD are efficient piped-water network simulation software and can be relied on for use in developing countries.