The middle route of the South-to-North Water Diversion Project was studied to make it safer to operate. A computer model was used to predict how water levels would change under different conditions. The results showed that without proper control, water levels could fluctuate by more than 0.15 meters at the check gate, affecting areas hundreds of meters away. When the gate was opened too fast, the water level changed at a constant rate near the gate. This study helps improve how the middle route of the project is controlled and operated.