Analysis of drinking water distribution systems using continuous-time discrete-event simulation

A drinking water distribution system consists of a network of pipes, treatment plants, storage tanks, pumps, and other hydraulic appurtenances. The system carries water from a well or a centralized treatment plant to the end consumers. Drinking water distribution systems are often studied using analytical models. However, these models do not capture the continuous behavior observed in the system such as continuous material flow from one point to another. This research uses a continuous-time discrete-event (CTDE) simulation model to capture continuous material flow from holding stations to distribution tanks, and finally to the consumers' taps. A case study from a geographical region in Najran City, Saudi Arabia, is considered. The CTDE simulation model is used to model a water distribution system (WDS) and to analyze the risk of water shortage by testing the impact of tanks' sizes on eliminating the water shortage. The results of the study show that modeling the WDS using the CTDE simulation model is an effective approach for capturing continuous behavior and the uncertainties that occur in continuous systems and should be considered as an alternative advanced tool that will contribute to improve studying and analyzing WDSs. To improve the performance of the WDS, numerical experiments were carried out and determined that water shortages in some regions can be eliminated by increasing the size of water tanks.