Water Conservation Technology for Recharging Over-Exploited Aquifers

A demonstrative experiment by the IFCGR/CEFIRES through the dry dug wells at Maheshwaram Watershed under the Indo-French Collaborative project


WATER CONSERVATION AND RECHARGE ENHANCEMENT ARE ESSENTIAL STEPS IN MANAGING WATER SOURCES IN THE GROWING DEMANDS

Situations are already alarming:
  • Most of the dug wells remain dry through out the year.
  • The pump in the bore-wells gets and pumps water for 45 seconds and run without water for the next 60 seconds.
  • Climate change is taking place. Both time and space variability of rainfall is changed and becoming unfavorable.
  • Ponds and tanks have become evaporative bodies.
  • Fluoride levels in groundwater are much higher than the WHO safe limit for drinking for the whole year.

Corrective measures often do not work and not foolproof due to the complexity, heterogeneity and variability of the underground systems. So it is necessary to think of preventive measures.

Could groundwater be managed without rainfall harvesting in the form of artificial recharge? The answer is no as there is a significant gap between dynamic resource availability and the demand. Thus the concept of groundwater banking has to be introduced.

The Technology (Steps to be followed):

  • A very clear and detailed conceptual model of the aquifer system
  • Sufficient knowledge of aquifer characteristics and system behavior
  • Preparation of Digital Elevation Model and selection of an existing dug-well having maximum catchment area with adequate slope
  • Simulation of regional flow in the aquifer and calibration of the model
  • Calculation of the runoff with various scenarios of the expected rainfall
  • Simulation of the enhanced recharge conditions in the model and verification of the forced infiltration results
The Advantages:
  • No-cost technology in the real sense except a little labour work
  • Effective and fast recharging
  • Regional effect expected due to presence of major fractures
  • Little loss by evaporation
  • Long life as in case of bottom silting also the walls continue water seepage
  • No major maintenance of de-silting
  • No additional area is occupied
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