Design and performance indicators for water harvesting irrigation tanks in India

Small reservoirs (known as tanks) for rainwater harvesting and supplementary irrigation are necessary for improving the productivity of rainfed agriculture in India.There are hundreds of thousands of such tanks in the country and many more being created. However these tank systems are not categorized for planning purposes. Review of these tank systems is necessary to understand the relationships amongst its component parts. In this paper these tank systems are reviewed with the objective of studying catchment-storage-command area (CSC) relationship. These systems are classified based on their physical setting and functioning. The CSC relationships for these systems show wide variation from region to region and also in the same region. In the literature there is lack of uniformity in describing these systems. Hence a classification system and ten indicators are proposed for describing these systems. It is suggested that when reporting such studies, the system should be discussed under one of the classes and the proposed indicators must be given along with other details.