The water footprint of the growing biofuel sector should be factored into discussions about water security (Nature 467, 555–561; 2010).

The rapid expansion of biofuel crops can significantly affect regional hydrological patterns (B. G. Subhadra Science 329, 1282–1283; 2010). In India, for example, jatropha plants — a biofuel feedstock with a large water footprint (W. Gerbens-Leenes et al. Proc. Natl Acad. Sci. USA 106, 10219–10223; 2009) — are increasingly being cultivated in rural areas.

Add to this the rapidly depleting groundwater in northwest India (M. Rodell et al. Nature 460, 999–1002; 2009) and the alarm sounds for prompt policy planning by the government to safeguard India's water resources.