Investigation of Integrated Management of Large-Scale Irrigation and Aquaculture Systems

The importance of nonirrigation uses of irrigation water to the livelihoods of the rural poor living close to irrigation systems has generally been ignored both in planning and operating these systems. An improved understanding of competition and complementarity of irrigation and nonirrigation uses is essential for increased productivity of irrigation water. This paper selected two typical types of large-scale irrigation systems as case study sites, i.e., the Lower Bhavani Project in Tamil Nadu, India—a canal-based irrigation system and Mahaweli System H, Sri Lanka—a tank-based irrigation system, and explored their potential for and constraints to integrated management for irrigation and aquaculture. The results revealed that for irrigation canals water supply reliability, canal flow velocity, and cage anchorage but for irrigation tanks water, supply reliability may impose constraints to integration of cage-based fish farming. However, the potential can be improved through more responsive operation and management of canal/tank irrigation systems, and enhancement in irrigation water use efficiency. This paper provides a valuable reference for irrigation managers and engineers in integration of cage-based fish farming within large irrigation systems.