Many irrigation schemes fail to generate expected levels and distribution of farm output and income. Overall system management, particularly operation and maintenance procedures, are major contributors to poor project performance both in terms of the level of farm income and its distribution. A combination of past irrigation investments and the use of high yielding varieties to feed an expanding population has made irrigation and irrigation management a central development issue. One of the problems associated with most studies of irrigation is the absence of a whole system perspective. The first component considers water management as a process involving various stages starting with planning and ending with operation and maintenance. In the water management system the institutional and organizational arrangements as well as implementation tools are just as important as the physical parts of the irrigation system. The chapter also presents an overview of the key concepts discussed in this book.