A barrage is proposed to be constructed across river Sabarmati 60 km downstream of Daroi dam to create reservoir within the bank for recharging and water demand of nearby areas. For analyzing the flow pattern and assessing the hydraulic parameters of Hipura barrage on Sabarmati river near Hirpura village of Mehsana District of Gujarat, a 3D physical model with geometrically similar scale 1:80 for river reach 3km (1km upstream and 2km downstream) and for assessing the adequate energy dissipating arrangement a sectional model with scale 1:40 are used. These experimental observations on physical models are carried out at GERI ( Gujarat Engineering Research Institute ), have been used to calibrate HEC RAS based model for Manning's roughness (n).The calibrated parameters of model are used to compute the hydraulic parameters in HEC RAS model in the steady state condition of flow in the river reach for 25%, 50%, 75% and 100% of design discharge 16785 m3/s (5.9 lakh cusec). From the observed values of velocities on ...