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Groundwater in Jawalgera village of Raichur district, Karnataka was unfit for human consumption due to brackishness and high fluoride content. Under World Bank Aided Project, IGIS carried out investigations, delineated a narrow aquifer of about 100m width where the water is not saline, but has high fluoride content. Artificial recharge of this narrow aquifer was implemented for diluting the fluoride content and augmenting the water source. IGIS conducted
Resistivity investigations to study the nature of subsurface formation to design the recharge structures, the results of which are presented in following figure. The clayey overburden of about 10m thickness is not favorable for recharge from surface methods. Therefore direct recharge through
bore wells was carried out through a well field (series of recharge and discharge wells) between 150 and 190m, where the aquifer thickness is maximum. The recharge wells were drilled within the zone of cone of depression of the pumping wells so that recharging into the ground is fast and dilution of groundwater takes place in the immediate vicinity of the pumping well. Nearby canal water is filtered with sand filters and is used for recharge through gravity flow. The initial fluoride content of the groundwater before artificial recharge was 1.9 mg/l and after one year of continuous recharge it has come down to 1.1 mg/l.
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