Modeling and optimization of pressure and water age for evaluation of urban water distribution systems performance.

Water loss has become increasingly critical as the severity of the water shortage situation has grown in recent decades. One of the options for reducing water loss in urban water distribution networks is pressure management. The study aimed to evaluate and optimize the existing water distribution system in the city. The proposed methodology is an interactive combination process between an optimization algorithm and WaterGEMS V8i to evaluate the performance of the distribution system. It was observed that, 43.80% of nodes (15-60 mHO), 5.10% of nodes (15 mHO), and 51.10% of nodes (>60 mHO) received pressure during peak hour demand. During low demand periods, only 4.4% of nodes (15-60 mHO) and 95.60% of nodes (>60 mHO) received pressure. The water age simulation results revealed that, 51.70% of the pipes were received water age <4.8 h, whereas the other 48.3% of the pipes were received water age <8.6 h during peak hour demand. During low demand periods, 45.58% of the pipes had a water age of less than 4.8 h while the other 54.42% of the pipes had water age of 4.8-20 h. The optimization result showed that after optimization, 4.4% of the nodes with optimum pressure increased to 75.18%, and 95.6% of the nodes decreased to 24.82%. Changing the size of the pipe based on the optimization result, and dividing an area into different pressure zones (adding more reservoirs at the far end of the distribution system) are all ways to improve or upgrade the distribution system.