Tank rehabilitation presently in vogue, in many states of India and neighbouring Sri Lanka, needs a holistic approach involving scientific planning and execution and people`s participation to save the tank and meet basic objective of providing water for irrigation. The article brings into focus the essential inputs to make the initiative successful. The main inputs include specialists’ reports on successful and failed initiatives in Karnataka, Tamilnadu, Pondicherry states and Sri Lanka.

This paper shows that winds of change are blowing in the dry zones of north-central Sri Lanka, the original hydraulic civilisation of the world. The social organisation of tank irrigation - which for centuries had combined a stylised land-use pattern, a system of highly differentiated property rights, and elaborate rules of community management of tank irrigation - has now been morphing in response to demographic pressures, market signals, technical change and modernisation. What are the lessons for south Asia and sub-Saharan Africa?

Farm tank (bodi) constitutes a small water reservoir constructed by using available natural materials to store rainwater for irrigation purposes during post monsoon season. It receives water from rainfall and runoff from the surrounding catchment area during monsoon period and this serves for irrigation purposes of paddy fields.

Agriculture currently produces only 30% of total income in the Telangana region, but it remains the basis for survival of nearly 78% of the population. During the 53-year period, 1956-2009, Telangana lost 2.92 lakh hectares of tank irrigation. Meanwhile, despite the high cost of irrigation – both in capital and operating costs – over the same period the area irrigated by tube wells has grown up. The latter is entirely dependent on the recharge of groundwater and the availability and cost of power.

The decline of groundwater levels in India by 5-10 m is usually explained as a result of the increased number of tubewells and a decline in average annual rainfall. This article argues that the decline is the product of the destruction of indigenous systems for storing runoff water, which are essential because rainy days are very few and erratic.

Climate change will affect water supplies in south Asia, where high-intensity floods and droughts are expected in the future. Increasing water storage is a key adaptation strategy, and the experience of irrigation tanks illustrates both the potential and challenges of this adaptation response.