A general optimal control model saltwater intrusion in coastal aquife density-dependent hydraulic and water quality response equations are presented. Different solution algorithms are described for the control problem imbedding method, Box's algorithms methodology (LSO). Se veral field applications are presented. The optimiz ation approach, despite requiring significant computation resources, is superior to co nventional simulation methods. optimal planning, design, and operational policie with environmental and hydraulic objectives. A general optimal control model was developed for the control of saltwater intrusion in coastal aquife r systems. The underlying sharp-interface and dependent hydraulic and water quality response equations are presented. Different solution algorithms are described for the control problem , including the Box's algorithms , and the linked simulation-optimization veral field applications are presented. The optimiz ation approach, despite requiring significant computation resources, is superior to nventional simulation methods. Optimization produces not only locally optimal planning, design, and operational policie s, but also tradeoffs associated with environmental and hydraulic objectives. coastal aquifer ; optimal control; salt water intrusion; simulation and