Potential of skimming wells for extracting relatively-fresh groundwater from unconfined aquifers underlain by saline groundwater

4-6 numbers of strainers and 1.5 m horizontal distance of strainers fromsuction point make these skimming wells cost-effective too.Canal water scarcity is widely prevalent in most of the (semi-) arid irrigated agricultural areas around the world. Resultantly, farmers have to increase their groundwater extractions,and thus groundwater resource emerged as a formidable poverty reduction tool. This is particularly true in vast and growing regions, like the Ganga-Meghana-Brahmaputra basin in South Asia, the Indus basin of Pakistan, and the areas of Vietnam, Laos and South China 'where the groundwater resource is already under threat. While developing groundwater resources promises to help alleviate poverty, the most formidable management challenge is to attain sustainable use of groundwater resource. Especially, while extracting groundwater from unconfined aquifers having relatively-fresh groundwater lenses overlying the saline groundwater layers, a major challenge is how to deal with deteriorating quality of pumped groundwater.This paper presents results of a study aimed at identifying potential of skimming well technology and operational management approaches for extracting relatively-freshground water from unconfined aquifers underlain by saline groundwater to help achieving sustainable use of groundwater resource. This study was conducted in the north-central part ofthe Chaj Doab 'area between Jhelum and Chenab Rivers in the Indus Basin of Pakistan. Four skimming wells of different configurations were installed at different locations to monitor hydraulic performance and hydro-salinity behaviours of skimming wells under different pumping regimes.Field and computer modelling studies indicated that daily operational hours affects significantly on the quality and quantity of pumped groundwater, and if skimming well is operated intermittently for 4-6 h/d under drought conditions, then this intermittent pumping would help in making tubewell operation cost-affective, and application of pumped water would also be less harmful to soil and crop.Without compromising the quantity and quality of pumped groundwater, 4-6 numbers of strainers and 1.5 m horizontal distance of strainers from suction point make these skimming wells cost-effective too.