This article reviews the various available methodologies to estimate submarine groundwater discharge (SGD) and demonstrates the utility of radon with a case study. An attempt has been made to identify the existence of submarine groundwater discharge (SGD)and semi-quantitatively estimate its rate in the coastal
area of Vizhinjam, Thiruvananthapuram, Kerala.

Environmental isotope techniques have been employed to identify the recharge areas of springs in India, in order to construct artificial recharge structures for rainwater harvesting and groundwater augmentation for their rejuvenation. A model project was taken up in the mountainous region of Gaucher