This paper presents the control design, implementation and preliminary validation of the cable-driven actuation of a floating platform for underwater desedimentation in reservoirs of hydropower plants. The system leverages cable forces to realize precise trajectory control within the planar water surface. Key challenges addressed include trajectory generation, control system structure, kinematics, and cable force distribution based on the system dynamics. The kinematics provides a numerical estimation of the platform pose, including the orientation. It also incorporates fluctuating water levels. The three planar degrees of freedom are dynamically coupled through the winch inertias. This aspect is incorporated into the calculation of the motor torques from the translational accelerations by considering the fully populated mass matrix. A modular control framework is implemented to perform both model-based simulation and physical hardware control. Preliminary test results demonstrate the system’s precision in tracking a predefined path at a fairly constant speed, thereby enabling uniform and seamless sediment removal.