Automation is one of the main options for improving operations and increasing flexibility in irrigation canals. Construction and testing of related technology is one of initial and main attempts in reaching this goal.. In this research PID classical control system was constructed, and tested at a laboratory flume. The hardware of the system includes the depth and gate opening sensors, motor, slide gate, electronic boards and computer. The software part of the system is the PID control system, which is developed and connected with equipments using LABVIEW software. To study the performance of the constructed control system, different scenarios of sudden changes of upstream and downstream flow were tested. Maximum Absolute Error (MAE), Integral of Absolute magnitude of Error (IAE) and System Response Time (SRT) indicators are used for evaluating the performance of the system. The results showed that the performance of the developed upstream and downstream control system is appropriate, However, downstream PID control system showed better performance when compared to the upstream PID control system. The developed PID automatic control system and experiences gained from constructed facilities could be implemented in irrigation canals.