Due to the recent integrated water management policy, it is important to identify a reliable supply amount for establishing an agricultural water supplyplan. In order to identify the amount of agricultural water supply, it is essential to calculate the discharge by measuring the water level and flow velocityof reservoirs and canal agricultural water, and quality control to ensure reliability must be preceded. Unlike agricultural reservoirs, canal agriculturalwater are more sensitive to the surrounding environment and reservoir irrigation methods (continuous, intermittent irrigation, etc.), making it difficultto estimate general water level patterns and at the same time a lot of erroneous data. The Korea Rural Community Corporation is applying a filtertechnique as a quality control method capable of processing large quantities and real-time processing of canal agricultural water level data, andapplicability evaluation is needed. In this study, the types of errors generated by the automatic water level measurement system were first determined. In addition, by using the manual quality control data, a technique with high applicability is derived by comparing and analyzing data calibrated withGaussian, Savitzky-Golay, Hampel, and Median filter techniques, RMSE, and NSE, and the optim...