Reliability/Availability Analysis of Water Distribution Systems Considering Adaptive Pump Operation

Abstract

Water distribution systems (WDS) are designed for delivering high quality water to consumers at desired pressures. Significant works have been conducted to measure and efficiently evaluate the performance and behavior of WDS. Although several literatures presented some methodologies for appraising WDS reliability/availability, few studies look at the impact of pump and tank operations while assessing WDS performance. In practice water utilities would take actions to respond emergency, such as pipe breaks, summer peak demand by turning on more pumps in short-term or maintaining a high water level in storage tank in long-term to meet the system’s pressure requirement. Therefore, to represent this reality, pump and tank operations must be addressed in WDS reliability analysis and potentially optimal design. Herein a practical WDS reliability analysis methodology is presented. The model takes into account pump operation schemes to quantify WDS reliability/availability that is defined as the probability that water distribution system can supply its consumers’ demand over a certain period. Monte Carlo stochastic simulation is conducted to hypothetically generate nodal demands and component failure. EPANET is employed as a hydraulic solver to estimate system pressure. Applications to mid-sized sample network show the adaptive pump operations as responding to pipe breaks improve system resiliency with trading in additional moderate pumping cost.