EGU22-2135
https://doi.org/10.5194/egusphere-egu22-2135
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Assessing the groundwater sustainability of Bengaluru megacity, India, through the lens of socio-hydrogeology 

Tejas Kulkarni1,2, Matthias Gassmann1, Chandrakanth Kulkarni2, Vijayalaxmi Khed3, and Andreas Buerkert4
Tejas Kulkarni et al.
  • 1Universitat Kassel, Institute of water, waste and environment, Department of Hydrology and Substance Balance, Kassel, Germany (tejas.kulkarni@uni-kassel.de)
  • 2Kiran Consultants, Bengaluru, India (kulkarni@kiranconsultants.com)
  • 3Department of Agricultural Economics, University of Agricultural Sciences, Bengaluru, India (vijayalaxmikhed39@gmail.com)
  • 4Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics—OPATS, University of Kassel, 37213 Witzenhausen, Germany (buerkert@uni-kassel.de)

Water extraction in Bengaluru, India's fastest expanding metropolis, entirely depends on its ~500000 wells in a crystalline rock aquifer, of which an unknown number has been abandoned and the level of others has sunk to depths of 450 meters below surface. Recent research has highlighted the spatial heterogeneity and questioned the reliability of water level data in these settings. To fill existing knowledge gaps on the likely over-extraction of groundwater as a vital resource we used a socio-hydrogeological approach of front-lining local hydrogeologists to collect primary data on the spatio-temporal evolution of well depths across the city. Our data show that over the past 60 years borewell depth has increased significantly while water yields have remained unchanged, indicating that digging deeper wells is unsustainable. Using camera inspections of 56 wells in a 2.1km2 catchment of industrial land use in Electronic City of Bengaluru, we noted that water levels in the wells are largely determined by rock fractures, not by well depth. Our data show that increased borewell depths is a good signal of declining water levels in Bengaluru’s aquifers. Analysis of δ18O and δ2H signatures of groundwater samples across all depths followed the local meteoric water line indicating recent recharge, implying that drilling deeper only increased the borehole volume and did not tap into newer water sources.

How to cite: Kulkarni, T., Gassmann, M., Kulkarni, C., Khed, V., and Buerkert, A.: Assessing the groundwater sustainability of Bengaluru megacity, India, through the lens of socio-hydrogeology , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2135, https://doi.org/10.5194/egusphere-egu22-2135, 2022.

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