This report presents the key findings of the research conducted in the RIPARWIN project: a multi-disciplinary investigation of water allocation and management in a water stressed catchment in Tanzania. The research, conducted over five years, demonstrated that: i) under certain circumstances, improving local irrigation efficiency is important because, by reducing non-beneficial losses, water can be liberated for other uses; ii) care is needed in the development of irrigation infrastructure intended to increase catchment level water productivity since, if inappropriately designed and managed, it can have the opposite effect; iii) economic efficiency is a necessary, but not sufficient, criteria for determining water allocation; iv) in situations where withdrawals are vital for livelihoods and poverty alleviation, it is not reasonable to plan to fully implement environmental flows and it may be necessary to manage trade-offs between different ecosystems; v) although care is necessary not to perpetuate past inequities, the effectiveness of contemporary approaches to water management may be improved if built on traditional arrangements which tend to be better suited to the livelihood strategies and social norms of local people; and vi) different types of decision support systems that improve understanding of system dynamics and facilitate social learning and dialogue can contribute to better water resource management. At a time when irrigation is being strongly promoted as a significant contributor to attaining the Millennium Development Goals, the findings are relevant to catchments in developing countries where there is competition for water and irrigation is one of the main uses.
Research Report 116. International Water Management Institute. Columbo, Sri Lanka. 56 pp.