Mumbai and Shanghai

The article ‘Chasing a Mirage: Water Harvesting and Artificial Recharge in Naturally Water-Scarce Regions’ by Dinesh Kumar et al (August 30) is a valuable contribution to research that questions the efficacy of localised water harvesting structures being promoted in the country. These structures, it is argued, are not efficient; they lead to negative trade-offs to users downstream and for users of water, other than for irrigation purposes. However, the evidence is contrary to that of research studies conducted at the micro watershed level, which indicate that groundwater recharge does occur even in hard rock areas (particularly, studies conducted by the University of Agricultural Sciences, Bangalore, including a recent study of the Sujala watershed project, funded by the World Bank in Chitradurga district of Karnataka).

The question to be asked is why are we getting such contrary results? Is it due to the methodological nature of the enquiry – research conducted at the local level, the micro watershed level vis-à-vis wider, subwatershed/milli-watershed or river basin level enquiries? While some research (micro watershed level studies) indicates that groundwater recharge occurs in hard rock areas and improves farmer income, other studies, such as Dinesh Kumar’s, suggest that the efficacy is likely to be poor.