This chapter deals with design aspects of gates and valve. These are required in a project to regulate the flow in different components of the project. These also facilitate repair and maintenance of structures. Normally fixed wheel vertical lift gates and radial gates are used. The layout and design features of these gates are described. The structural design aspects of various structural components of these gates are also described. An automatically operated bye-pass gate is also dealt here. Valves are provided at the end of penstock and are generally located inside the power house. These are either butter fly valve or spherical valve. Spherical valve is generally used for high head projects. Their construction and operation are also discussed in this chapter.