Agriculture is the backbone of developing countries, the 26, December 2004 ‘Tsunami’ had a major impact on the quality of groundwater along the south- east coast of India, but especially in the tsunami-affected coastal areas of SirkazhiTaluk of the Nagapattinam district of Tamilnadu, India. Major pollution resulted primarily from increases in the salinity of ground water. The post- tsunami water quality posed problems to general health and contributed significantly to agricultural and environmental degradation in the same districts. The present study focus on analysis of underground water quality parameter for irrigation purpose in coastal area. Totally, 105 water samples were collected from different locations. GPS technique is used to identify the coastal area and collected the samples. Physiochemical parameters such as pH, electrical conductivity(EC), total dissolved solids(TDS), carbonate, bicarbonate, chloride, calcium, magnesium, sulfate, sodium, potassium of all collected samples were analyzed  to determine the contamination. The sodium adsorption ratio (SAR) and residual sodium carbonate (RSC) levels were also calculated using standard equations. The results showed the significant variations in water quality in the study area, which helped analysis suitable to irrigation purpose in future.