New IEEE Standard - Superseded. Descriptive material intended to assist in the planning for design, development, and operation of small hydroelectric power plant control systems is presented. The controlled electrical and mechanical systems and equipment as well as the control systems are covered. The aim, which is basically tutorial, is to provide a working knowledge of the terminology used in this field and an understanding of the principles of operation of hydroelectric generating units. The control requirements are addressed from an electrical standpoint. For completeness, salient civil features of small hydroelectric projects, are mentioned and equipment protection and operation are discussed.