The study area of Karimganj district for aquifer mapping is bounded by 24.9168°N, 92.2976°E in northern side and 24.9168°N, 92.2976°E in southern side while 24.9168°N, 92.2976°E in western side and 24.9168°N, 92.2976°E in eastern side covering an area of 1809 sq. km of Karimganj district of Assam. The study area is situated in the Barak Valley of Assam. It is occupied by the folded sedimentary formations of Surma, Tipam, Dupitila, Alluvium groups ranging in age from Lower Miocene (Tertiary) to Holocene (Quarternary). The regional strike of the folded geosynclinal facies sequences is NNE-SSW. The major rivers in the district are Barak, Kushiara, Longai, Singla. All the rivers are rain fed and drain the major valley in the area. There is no major or medium irrigation project present in the district. In the district, two principal aquifers have been delineated. • Alluvial aquifer of Quaternary age - The alluvial aquifer consists of clay, sand and clayey sand. The clay is yellowish brown in color. • Sandstone aquifer of Tertiary age - The sandstone aquifer is composed of friable sandstone with clay. Sandstone occurs as lenses and the color of clay is grey.