1. The block diagram of the operating governor system of Kaplan turbines is made so that its inaccuracy is determined not only by the inaccuracy of the governor mechanism itself but also by the free play in the drives of the gate apparatus and runner. 2. The total maximum value of the inaccuracy of the governor system at operating turbines under their normal operating conditions can reach 2–3°, which reduces the efficiency of the turbine by 0.2–0.7%. 3. To improve the economic efficiency of operation of Kaplan turbines it is necessary to try to increase the accuracy of the governor relationship, and periodic monitoring of the state of the relationship should be set up during operation of the turbines.