Satellite-based estimates of groundwater depletion in northwestern India reported by Matthew Rodell and colleagues (Nature 460, 999–1002; 2009) should be backed up with precise ground-based information for the whole of India, taking into account regional variations in rock types, aquifers and watersheds. This will help to ensure effective local remedial action.

I have worked among poor farmers in Indian villages and believe that, if the government withdraws electricity subsidies for operating groundwater pumps in northern India, it could lead to drought in agricultural regions. Suicides among farmers have already occurred in response to drought in Maharashtra and Andhra Pradesh.

As the authors point out, use of groundwater in northern India needs to be sustainable. But drought should not be induced as part of the solution.