In the present study the pollution of a major North Bihar lake, the Kawar Wetland was studied with special reference to their effects on flora, fauna and local human population. The water of the lake is turbid, acidic and is having higher conductivity. The dissolved oxygen level was estimated as 7.6 mg/L, free CO2 6.3 mg/L, bicarbonate 80 mg/L, hardness 90 mg/L, chloride 17.0 mg/L.