The Karjan dam is located on the Deccan Basalt flows of Cretaceous - Eocene age in the Narmada valley in Gujarat state. A characteristic feature of the basalt flows in this area is conspicuous presence of a number of sub-horizontal weathered rock seams posing the foundation problems of settlement, sliding and seepage. Concrete shear keys have been provided to increase the sliding stability of dam blocks besides other remedial measures. Additional curtain grouting has been done after completion of the dam to reduce seepage
