Hydraulic modeling of Water Distribution Networks (WDNs) is an important task towards the development of efficient water management practices and strategies, aiming at the reduction of water losses and the associated financial cost and environmental footprint.
In the current work, we develop an easily applicable methodology for effective modeling of WDNs, which seeks to minimize the computational load while maintaining a sufficient level of estimation accuracy, using the public domain EPANET software engine. To realistically describe a WDN, we use sensitivity analysis to determine the appropriate nodal density, which should be high enough as to effectively describe both topographic variability as well as the original connectivity of the network, while taking into account all necessary hydraulic parameters (e.g., pipe diameters and materials used). To conduct the hydraulic simulation, we firstly define the total water demand at each computational node of the network, as the sum of a demand-driven and a pressure-driven component. The demand-driven component depends on the flow time pattern, as users’ consumption varies during the day, while the pressure-driven component reflects the network’s leakages, which are an increasing function of the applied pressure. Modeling of leakages is conducted by borrowing concepts from Torricelli’s Law, assuming that the distribution of leakages is proportional to the square root of the excesses of the simulated nodal pressures above the minimum pressure required to meet the consumption standards.
The effectiveness of the proposed methodology is tested via a large-scale, real-world application to the 4 largest Pressure Management Areas of the WDN of the city of Patras, the third largest city in Greece.