In this paper, we propose a complete modeling approach of hydraulic power plants and a control solution to improve the start-up performance of hydraulic turbines. This paper presents a novel simple speed controller that is capable of starting-up hydraulic turbines fast enough while limiting sharp pressure head oscillations. Its simplicity makes it easy to adopt by practitioners, and capable of running on existing power plants which utilize microcontrollers with limited computational abilities. The controller structure proposed in this paper has the potential of being tuned such that closed-loop stability is guaranteed and upper bounds on asymptotic tracking error are minimized. A modular mathematical model is also proposed where the method of characteristics is used to model water dynamics in multiple penstocks used in hydraulic power plants. The main problem that rises when modeling a system of multiple penstocks is systematically choosing the sampling period. Therefore, we propose a systematic approach to choose any sampling period. This leads to the development of a modular hydraulic simulator that takes into account power plants with multiple penstocks, the nonlinear dynamics of the hydraulic turbine, modeled by regression models generated using Hill charts data points and the guide vanes opening actuator's full nonlinear dynamics. (C) 2020 Elsevier Ltd. All rights reserved.