Floods are phenomenon that grip more than half of the world population and span over all the continents with an exception of Antarctica. The use of hydrodynamics in demarcation or delineation of flood-prone zones can significantly impact the process of flood mitigation and management. This chapter entails the study of flood event that inundated several parts of Delhi National Capital Territory (NCT) during the monsoon season of the year 2023. The study is focused on the stretch of Yamuna River from the Wazirabad Barrage to the point where Yamuna River exits the NCT of Delhi. Datasets that have been procured for the purpose are Shuttle Radar Topographic Mission (SRTM 30 m digital elevation model [DEM]), discharge datasets released by the Flood and Irrigation Department of Delhi, alongside the Census data of population. A two-dimensional hydrodynamic model is developed using the datasets as inputs into the HEC-RAS software version 6.4.1. The discharge data released by Flood and Irrigation Department of Delhi NCT government records the amount of water discharged from the Wazirabad Barrage into the river channel. A flow hydrograph at the downstream end of Wazirabad Barrage as the inflow point for the flow region has been calibrated, whereas the normal depth function has been used for the outflow point that lies at the point where Yamuna River exits the union territory.