This book covers modeling, simulation, and adaptive control of a multi-stage flash (MSF) seawater desalination plant. It outlines the principles of MSF desalination and highlights the importance of the various control systems for large MSF plants. Topics include a satisfactory dynamical model of the plant, an optimal method of approximating the model to the standard first-order-plus-dead-time (FODT) form, a dependable method of simulation and optimization that can handle the original unreduced model, and an optimal controller tuning based on integral criteria.