This article summarizes the results of water productivity assessment in 10 river basins across Asia, Africa and South America, representing a range of agro-climatic and socio-economic conditions. Intensive farming in the Asian basins gives much greater agricultural outputs and higher water productivity. Largely subsistence agriculture in Africa has significantly lower water productivity. There is very high intra-basin variability, which is attributed mainly to lack of inputs, and poor water and crop management.

The authors of the recently completed Comprehensive Assessment of Water Management in Agriculture (CA) concluded that there are sufficient water resources to produce food for a growing population but that trends in consumption, production and environmental patterns, if continued, will lead to water crises in many parts of the world.

This paper draws on the development and use of water resources in the Lower Bhavani Project (LBP), with the LBP reservoir and the 84,000 hectare (ha) LBP command area. The project diverts water from the Bhavani River, a tributary of the Cauvery River, in the South Indian state of Tamil Nadu.

The Comprehensive Assessment of Water Management in Agriculture is a critical evaluation of the benefits, costs, and impacts of the past 50 years of water development, the water management challenges communities face today, and the solutions people have developed around the world.