EXPERIMENTAL ANALYSIS AND COMPUTER SIMULATION OF A LABORATORY-SCALE INTERMITTENT WATER SUPPLY SYSTEM

Intermittent water systems (IWS) are prevalent throughout developing regions of the world. However, few tools exist to predict IWS performance because modeling transient flow is difficult: IWS networks can experience widely fluctuating conditions, ranging from completely empty to completely full (pressurized flow). An experimental IWS, consisting of a 50.75-gallon reservoir, an elevated distribution network, and four outlets was constructed to study the hydraulics of IWS. Three experiments were run on the system that represented two falling-head scenarios and a constant-head scenario. Computer simulation models of the experimental IWS were developed in EPANET 2.2.0 and EPA-SWMM 5.1, which are open-source modeling software for pressured water distribution networks and stormwater conveyance systems, respectively. EPANET 2.2.0 was incapable of representing flows observed in the experiments, likely due to the steady-state assumptions inherent to its global gradient algorithm. However, EPA-SWMM 5.1, which models the propagation of network flows with dynamic wave routing, was able to generate outflow hydrographs that emulated experimental discharge flows. Therefore, it is recommended that further verification be undertaken to validate SWMM’s capacity to model IWS systems under a range of hydraulic scenarios. If SWMM can withstand rigorous experimentation, potential may exist for this software to be retooled for the design of IWS