In this study, it has been revealed that physical water losses in drinking water networks are one of the important issues in the protection of water resources. The demand for drinking water is increasing day by day with the increase in population. On the other hand, the amount of potable water is decreasing and the effective use of water in drinking water networks becomes important. The water that is given to the water network but does not reach the users is known as lost leakage. Lost and leaks are called physical and visible losses. In order to determine the water loss and leakage level in the research, the amount of water supplied to the system for 2020, the number of pipe failures, the amount of water consumption according to the usage areas, and the minimum night flow information were obtained from the municipality. In order to determine the water loss and leakage level in the Merzifon sample, the infrastructure leakage index was determined by creating a water balance. In the Merzifon sample, it was determined that the amount of physical water loss and leakage for 2020 was 44.12%. The infrastructure leak index (ILI) was determined as 13.6. In order to protect the water supply, pressure management in the drinking water network, network renewal, active leakage control, improvement of repair speed and quality should be done.