Variations in stable isotopes of oxygen and hydrogen in surface and groundwater of a managed aquifer recharge site; a case study

Groundwater storage augmented by Managed Aquifer Recharge methods in a region will help to manage water supply when there is insufficient availability surface water. The present study was carried out to use the stable isotopes of oxygen and hydrogen to study the interaction between the surface and groundwater at Managed Aquifer Recharge (Check dam) site located north of Chennai, Tamil Nadu, India. Water samples from check dam were collected at periodical intervals from October 2011 to April 2012 and groundwater samples from the wells surrounding the dam were collected for the period between January 2012 and July 2012. Electrical conductivity of the water samples was measured using multi parameter probe (YSI 556). Chloride is analysed by standard titration method. delta D and delta (super 18) O were analysed by PICARRO L1102-i isotope analyser. The variation in isotopic signatures of water from the check dam indicated that water stored in the check dam undergone various degrees of evaporation. The relationship of delta (super 18) O with electrical conductivity and chloride of groundwater and water from check dam assisted in delineating the wells recharged from check dam. It is identified, that the wells located 1.5 km surrounding the check dam is benefitted by this structure.