In this handbook four maintenance plans, namely (a) essential structures maintenance, (b) normal maintenance, (c) "catch-up" maintenance, and (d) preventive maintenance, have been developed to provide guidelines to identify problems, develop solutions and implement the same for improving irrigation systems. a flow chart illustrating the sequence of the scientific approach has been provided. a 'walk-thru' diagnostic survey rather than a 'drive-thru' survey for ascertaining the maintenance needs has been proposed as it provides field personnel with a greater understanding of the causes of maintenance problems and provides them with valuable experience in the application of remedies to these problems.