Groundwater depletion and water extraction cost: some evidence from South India

Abstract

From less than 6 million ha in 1950–51, groundwater-irrigated area increased to about 45 million ha in 2010–11, which is over 62% of India's net irrigated area. But the rapid development of groundwater has brought many negative outcomes for farmers. An attempt is made in this study to find out the losers and gainers of groundwater irrigation using survey data on 234 dug-well- and bore-well-owning farmers selected from two regions having different agro-economic settings in the Pudukkottai District of Tamil Nadu, a state in South India. The study shows that the dug-well- and bore-well-owning farmers had to incur a huge additional cost on account of modifications of wells in order to keep up with the falling water level. The modification cost alone accounted for about 33–48% of the real capital of bore-wells. The pumping cost of water is found to be higher for bore-wells fitted with submersible pump-sets as compared to deep bore-wells fitted with submersible pump-sets.

Keywords::

• irrigation
• well irrigation
• groundwater depletion
• extraction cost
• Indian agriculture

Acknowledgements

This paper forms part of a larger study on Losers and Gainers of Groundwater Irrigation Development: An Empirical Study from Peninsular India, sponsored by the International Water Management Institute, Colombo, Sri Lanka, under the IWMI-TATA Programme. The author is thankful to Dr M. Dinesh Kumar and Dr K. Palanisami for their continuous support and encouragement in completing this study.

Notes

1. Revenue village is the basic administrative unit followed in rural India which has definite surveyed boundaries. The revenue village need not necessarily be a single village, and sometimes it may comprise several hamlets depending upon the geographical area of the village.

2. The terms such as well structures, groundwater structures and well types are used interchangeably in this study, and convey the same meaning.

3. For the purposes of this study, bore-wells with depth more than 200 feet are defined as deep borewells and wells with depth of less than 200 feet are defined as shallow bore-wells.

4. Filter point (FP) wells are normally installed in an area where the water level is near the surface. Normally filter-point wells are very shallow and are installed very close to a river bed or tank basin, where water recharge in the well is expected to be large.

5. The life period of wells generally varies from one location to another. The dugwells or borewells installed during the 1970s and 1980s are reported to have been working for 15–20 years for some farmers with multiple modifications. However, the life period of wells installed after the mid-1990s seem to have fallen significantly because of over-exploitation of groundwater and climate variability. Some wells have not lasted for even five years. Since a vast majority of farmers were able to operate their wells for 10 years by employing some modifications, the life period of wells is considered as 10 years for this analysis.