The decrease in water availability at watershed levels due to subsidies is a critical concern for India considering the monsoon response to global warming.
A new study has pointed out that increased irrigation efficiency does not translate into more water availability for other uses at the watershed level. The subsidies for increasing irrigation efficiency are intended to increase crop production as well as more return flow from irrigated areas that can be allocated to urban, domestic and industrial uses. But this does not seem to be happening.
The study, published in journal Science, by Quentin Grafton of Australia with co-authors from France, UK and the US underscores what has been observed in recent years. It cites Rajasthan as one of the examples where increased irrigation efficiency due to approaches such as drip irrigation has led to increase in crop yields and agricultural incomes. At the same time, there is also an increase in irrigated area and water withdrawals.
While groundwater management is under the purview of state governments, the central government incentives to the state focus on irrigation efficiency as a step towards climate resilience. A 2017 study by the US geographer Trevor Birkenholtz had reported that farmers adopting drip irrigation are generally commercial scale farmers who can afford the high costs and are also aware of increasing water demand from drip irrigation. Considering that nearly 80 per cent of water supply for both irrigation and domestic use is from groundwater, dependence on irrigation efficiency for groundwater sustainability may be misplaced.