Water productivity may carry different meanings to different people, and may differ between but also within groups of water users. The term water productivity is used exclusively to denote the amount of the product over the volume of water diverted. This research paper presents one-dimensional hydrodynamic modeling of a steady flow analysis on the Purna river of the Navsari region, India. ArcGIS and HEC-RAS software were used to find out water level at different cross-section in 62 km stretch of river reach. Carto DEM of 1-arc second resolution was pre-processed in ArcGIS v10.5 to extract the cross-sections for hydraulic modeling. Hydrologic Engineering Centre’s- River Analysis System (HEC-RAS v5.0.7) software was used to carry out the analysis of hydraulic parameters for past flood data. Total 246 cross-sections were analyzed to check the carrying capacity of the 62 km stretch of the river for the peak flood discharge of the years 2004 and 2005. The results show that around 40% of the total cross-sections were not having the capacity to safely pass the flood discharge. So, construction of retaining walls, embankments, stone-pitching, and detention ponds were suggested to prevent the flood inundation of the surrounding region. The study presented in this paper would be helpful in the infrastructure planning for decision-makers to prevent the loss due to floods in low-lying areas.