Hydrogeochemistry of Tattihalla watershed was carried out to evaluate and assess its quality for domestic, agricultural and industrial suitability. Major ion chemistry such as Ca, Mg, Na, K, CO3, HCO3, Cl and SO4 were analysed. Physical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS) and hardness (H) were analysed. Piper’s diagram plot revealed the hydrochemical facies to be of type- Mixed CaMgCl and Mixed CaNaHCO3. Physico-chemical analyses were carried out following standard guidelines (APHA, 1995) and its quality for different parameters were compared with Indian (BIS, 2003) and International (WHO, 2005) standards. EC value ranges from 34 to 235µS/cm and falls in excellent category. Sodium absorption ratio (SAR) classification for irrigation suitability indicates the water samples are in excellent category, suggesting that the low salinity and alkalinity. Wilcox diagram (1954) indicates the water samples falling in excellent to permissible category. Residual sodium carbonate (RSC) classifications were revealed that the water samples falling in good category and free from bicarbonate hazard.
