The easy accessibility of groundwater by even small-scale users, its local availability and the difficulty of coordinating and governing many users of the same aquifers across wide geographic spaces has frequently led to indiscriminate extraction of this precious natural resource for domestic, industrial and agricultural uses around the world. Groundwater exploitation, particularly in India, has increased by leaps and bounds over the last 50 years along with the expansion of shallow, mostly private, wells. The growth of groundwater abstraction structures from 1950 to 1990 clearly depicts the increasing use of groundwater utilization across sectors. As per available published statistics, the number of dug wells increased from 3.86 million (1951) to 9.49 million (1990) and of shallow tube wells from 3000 (1951) to 4.75 million (1990) (Muralidharan and Athavale, 1998). Shah (Chapter 2, this volume) highlights that these trends continue to the present.

The reasons for the increase in groundwater use in India are varied and include technological, hydrologic and policy factors. Technologically, developments over the last 50 years in the construction of deep tube wells, water abstraction devices and pumping methods have made large-scale exploitation of groundwater both possible and economic. At the same time, changes in hydrologic regimes, in particular the growing scarcity of surface water supplies as agricultural and other users have expanded, have pushed water users to seek groundwater alternatives. Finally, government policy has tended to support groundwater use. Easy availability of credit from financial institutions for sinking tube wells coupled with the provision of subsidized or free electricity (see Shah et a/., Chapter 11, this volume) for pumping in many states has encouraged increased extraction.

As demand for groundwater has gone up, rapid urbanization and land use changes have decreased drastically the already low infiltration rates of rainfall ┬ęCAB International 2007. The Agricultural Groundwater Revolution:

Opportunities and Threats to Development (M. Giordano and K.G. Villholth) 195

into the soil and have diminished the natural recharging of aquifers. Natural recharge measurements carried out in about 20 river basins across India suggest that about 15-20% of seasonal rainfall contributes to groundwater recharge in the Indo-Gangetic plains, figures that fall to only 5-10% in the peninsular hard-rock regions (Athavale et al., 1992).

Increased use and limited recharge have contributed to the lowering of the water table so much that yields of many dug and tube wells have decreased substantially or even fallen to zero, particularly during the summer. The drinking water crisis that ensues in many villages in summer imposes serious health hazards to the rural masses and is responsible for the huge loss of livestock populations for want of drinking water and fodder (Shah, 1998). The general implications for agriculture are no less severe.

To respond to the growing groundwater crisis and take advantage of the high levels of runoff not captured by natural recharge, augmentation of groundwater resources through artificial recharge of aquifers has become widespread in India over the last 3-4 decades. In fact, the growth in the use of artificial recharge has expanded to such an extent that it can be called a 'groundwater recharge movement', which has behind it both secular and spiritual proponents. This recent movement builds on artificial groundwater recharge concepts that have been practised from time immemorial in the hard-rock, semi-arid regions of south- and north-western India.

In some senses, the artificial recharge movement in India can be considered as a successful example of community-based efforts to manage common property resources. However, because of the distributed nature of aquifers and their interconnectivity across space and with surface water supplies, recharge by one group or community may impact water availability for other neighbouring or downstream groups. Thus, the artificial recharge movement in India highlights both the benefits and problems of community-based approaches highlighted by Schlager (Chapter 7, this volume).

This chapter looks at the historical evolution of the groundwater recharge movement in India, how it has gathered momentum, who has been responsible for it and what it has achieved to date. Through two contrasting case studies, it then highlights both the clear local benefits of artificial recharge and the potential for negative impacts at larger scales. Together these studies show the potential gains and the governance problems that will necessarily follow the artificial recharge movement as it continues to move forward in India. The studies also provide some guidance in how artificial recharge can, and cannot, be used to solve groundwater problems.

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