FLOOD FORECASTING UPTO GARUDESHWAR WEIR IN LOWER NARMADA BASIN USING HEC-RAS
Keywords:
Flood modelling, Narmada river, Garudeshwar weir, Statue of unity, HEC-RAS, Return Period.Abstract
There are many dam construct on Narmada river. Sardar Sarovar Dam(SSD) is One of the largest multipurpose dam on Narmada river. During the monsoon period, when the SSD is full at its Maximum Reservoir Level (MRL) and still the surplus flow is approaching, which is released from the dam to avoid the overtopping. This will result into wastage of valuable water into sea which can be used during low inflow in the dam. Garudeshwar weir has been proposed to construct at the downstream of dam which will create tail storage for running RBPH turbine a thought year. Garudeshwar weir will lead to increase water level due to back water flow flood situation will arise between Garudeshwar weir and SSD.
With the advent of modern technology, the use of sophisticated software in flood modelling helps in getting an idea of extent of flood at its submergence. Hence, to facilitate in getting an idea of extent of flood and its submergence flood forecasting study at Garudeshwar weir which is 12 km downstream of SSD is consider for the modelling using HECRAS software. In this present study river reach of 12 km between weir and SSD including 28 cross sections and submersible bridge is selected for modelling.
