PURPOSE: To prevent the rotary part in a turbine from dynamically lifting when a diagonal flow water turbine or propeller water turbine having runner vanes is stopped its operation, by operating the control of closing a guide vane and opening an angle of the runner vanes during the time from the opening degree of the guide vane at parallel off time of the turbine to a specific opening degree.

CONSTITUTION: At time t0 when given a start command of stopping the operation of a water turbine, the opening degree of a guide vane 4 is controlled to a close direction simultaneously the angle of a runner vane 2 is controlled also to be decreased, and at time t1 when the angle of the runner vane 2 becomes zero for the turbine in the vicinity of no-load the main turbine is parallelled off from a power transmission line. At time t2 when reached a predetermined degree of opening A0 during the time from the opening degree of the guide vane 4 at the parallel off point of the turbine to 8% degree of opening of the guide vane, a solenoid for controlling the runner vane 2 to the direction of an increase of its angle is operated. At time t3 when the guide vane 4 is fully closed, the angle of the runner vane 2 is considerably increased to enable the operation of stopping the water turbine without causing the lifting of a rotary body.