Among ecosystems services, freshwater is one of the most fundamental for life. For smallholders, water means the difference between a decent life and poverty, hunger and malnutrition. The majority of poor rural people depend on rainfed farming systems for their livelihoods: the Food and Agriculture Organization of the United Nations (FAO) estimates that, globally, rainfed agriculture is practised on 83 per cent of cultivated land, and supplies more than 60 per cent of the world’s food. But this precious resource is under stress, with massive potential impacts on the livelihoods of poor rural communities.