DIAGNOSTIC ANALYSIS AND FINE TUNING OF SKIMMING WELL DESIGN AND OPERATIONAL STRATEGIES FOR SUSTAINABLE GROUNDWATER MANAGEMENT ‐ INDUS BASIN OF PAKISTAN

Abstract

ABSTRACT A survey was conducted in the Chaj Doab (the area between the rivers Chenab and Jhelum) to characterize the skimming wells used to extract freshwater layer. The survey revealed a drastic increase in the number of skimming wells installed during the drought period from 2000 to 2002. About 36% of skimming wells were found to pump water of EC greater than 2.0 dS/m. The number of strainers varied from 2 to 20 and the size varied from 5 to15 cm. The prevailing depth to the water table in the area ranged from 2 to 10 m, whereas the strainers of the wells were usually at 18 m depth. The spatial and temporal variability of groundwater quality was very high. Based on pumping test results and analysis, it is suggested that skimming wells of about 28 lps discharge should not be installed within a radius of 350 m. Six strainers of 7.5 cm diameter are recommended for installation within a depth of 20 m to pump about 28 lps of water. The skimming wells may be operated continuously for 4 to 12 hours/day, depending on the source of recharge, without having adverse effect on groundwater and pumped water quality. Copyright © 2011 John Wiley & Sons, Ltd.