We analyze tunnel wells (surangams), traditional water harvesting systems, which have been innovated and nurtured by farmers in the Enmakaje panchayat in the state of Kerala in South India for decades. We show how the genesis and design of the indigenous knowledge-based water harvesting systems are shaped by agro-ecological conditions. We also identify issues that affect the sustainability of tunnel wells in the changing agrarian context in this region.

Agricultural systems as well as other ecosystems generate ecosystem services, i.e., societal benefits from ecological processes. These services include, for example, nutrient reduction that leads to water quality improvements in some wetlands and climatic regulation through recycling of precipitation in rain forests.

The global demand for water in agriculture will increase over time with increasing population, rising incomes, and changes in dietary preferences. Increasing demands for water by industrial and urban users, and water for the environment will intensify competition. At the same time, water scarcity is increasing in several important agricultural areas.

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.

Participatory irrigation management (PIM) reforms are implemented in India to facilitate farmers