Water itself is an energy resource. Monitoring all sources of pollution to assess the loads contributed by these sources is rather difficult if not, impossible, expensive and subject to analytical errors. Indirect methods to study source contributions of pollutant loads are essential to control water quality degradation in rivers. The objective of the present investigation is an attempt to assess the surface water quality of Nambiyar River Basin using statistical methods. The Nambiyar basin falls in Tirunelveli, Thoothukudi and Kanyakumari districts of Tamil Nadu. The Bio-Physico and Chemical parameters of the Nambiyar Basin have been taken in to account to find the interrelationship among them. The SPSS and Windows Excel were used as the statistical analysis tool. Based on the study it is found that strong correlation exists between TDS and BOD, SO4, COD. The highest interrelationship was obtained between SO4 and COD (r = 0.9532). A suitable regression equation has been established for the water quality parameters which have correlation coefficient greater than 0.8.These equations can be used for the rapid monitoring.