This document provides an overview of the hydraulic design considerations for barrages. It discusses key aspects of barrage design including sub-surface flow calculations to determine seepage pressure, force, and exit gradients. It also covers surface flow hydraulics to determine the waterway length. Critical design elements like cut-offs, scour depth, block protections are explained. Emphasis is given to ensuring safety against piping failure and sand boilling. The document concludes that model studies are necessary before prototype construction due to uncertainties in soil properties.