A simple, practical method for finding the numbers of skilled personnel necessary for the successful implementation of irrigation projects in developing countries, and for designing a training system to generate this personnel is given. The occupations critical to irrigation development and the agricultural activities in which each occupation is deployed are listed. A series of coefficients, based mainly on the successful irrigation development in northwest Mexico, determines the manpower quantities required as functions of given project parameters. A network flows model and a linear programing model are developed for designing the appropriate training systems.