Let’s first explore what water balance in a sewage treatment plant is: the balance of the total inflow and outflow of the sewage treatment plant. Nowadays, the issue of imbalance in the inflow and outflow of sewage treatment plants has increasingly drawn the attention of relevant regulatory authorities and various sewage operation companies. The imbalance between the influent and effluent water volumes is extremely severe, which is influenced by factors such as the sewage and sludge treatment process, the amount of reused water, the level of equipment, and the installation position of flow meters.