Opportunities for energy-free groundwater extraction through artificial autoflow well: a conceptual feasibility in Indian context

Prospects for converting a water well tapping confined aquifer into an artificial autoflow well exists in several areas. However, the energy advantage offered by a confined aquifer is generally ignored and even in areas where the piezometric head in the well rests at very shallow depth from the ground surface, pumps are lowered for extracting groundwater. In this paper, we present a conceptual feasibility of converting wells constructed in confined aquifers into an artificial autoflow well. There exists a promising prospect of creating an artificial autoflow condition which can lower the dependence on energy for groundwater extraction. Such wells are feasible in areas with multi-aquifer set-up where a thick layer of surficial clay overlies the main aquifers making the area unsuitable for dugwells; areas where the water level in the top unconfined aquifer (phreatic aquifer) has declined below 20 m from ground level resulting in drying up of dugwells and shallow handpumps and; areas where the shallow aquifer is contaminated and not suitable for drinking and domestic uses and the deeper confined aquifers are contamination free. A suitable design for an artificial autoflow well is proposed in the paper which can provide an energy free alternative for groundwater extraction for meeting the requirement of small and marginal farmers as well as for meeting the drinking and domestic requirements of rural households in areas where the shallow aquifer system is either contaminated or desaturated.