Because of the serious situation of environmental pollution all over the world, the water hydraulic technique using pure tap water as a pressure medium has become new drive source comparable to electric, oil hydraulic, and pneumatic drive systems. Furthermore, water hydraulics is also preferred because of its high power density, clean, high safety against fire hazards, and easy availability. However, the main problems for precise control in water hydraulic systems are steady state errors and overshoot due to its large friction torque and considerable leakage flow. In this study, a simple adaptive control (SAC) algorithm that is appropriate for dealing with these problems will be applied to a water hydraulic servo motor system for both angle and velocity controls. SAC also has simple, lower order structure, and few adaptive parameters; thus, it is high feasibility in real applications. For both angle and velocity controls using SAC, the tracking performances are good in simulation: 0.08 degree and almost 0 revolution per minute (min-1) for angle and velocity controls, respectively. The controllers also can highly attenuate the effects of disturbances.