Water Distribution Systems Reliability under Extended-Period Simulations

Abstract

Water distribution systems reliability has typically been studied using single-period simulations of the hydraulic behavior of the system, due to high computational requirements. The aim of this work was to develop and test a framework for the evaluation of mechanical reliability, hydraulic reliability, and firefighting reliability under extended-period simulations. Four functionality functions were proposed to quantify the serviceability of the system under the perturbation scenarios. The functions were tested in five case studies based on real-world networks and compared with the previously developed mechanical reliability estimator (MRE) and hydraulic reliability estimator (HRE), as well as with similar definitions for single-period simulation. Results showed that both MRE and HRE consistently correlate with the supply/demand ratio functionality, and are easy to compute even in optimization routines. Comparison results with single-period definitions of functionality showed that, on average, evaluating hydraulic conditions at the peak hour works is a good estimation of the extended-period behavior, but in some cases, discrepancies up to 50% can be found.