Hydrological and Hydraulic Modelling for River Sabarmati Stretch in Ahmedabad using HEe-RAS and HEe-HMS

The River Sabarmati is one of the major west flowing rivers of India and Ahmedabad and Gandhinagar are the major cities that are located on it's banks. In the past, heavy floods in the River Sabarmati River have devastated the city ofAhmedabad. Hence the flood levels in the river section are required to be estimated taking into consideration the upstream structures for future flood control measures. This paper describes the rainfall-runoff modelling for the River Sabarmati at Ahmedabad that has been carried out using the HEC-RAS (v 3.1.3 -May 2005) and HEC-HMS (v 2.2.2 - May 2003) software developed by United States Army Corps of Engineers (USACE). The flows have been simulated for the three historical most severe storms designated as design storms by the CWC using the HEC-HMS and HEC-RAS software. Peak flows and river stages in River Sabarmati have been computed taking into account, the reservoir storage at the time of storm event based on the rule curves developed by NIH-Roorkee. Based on the analysis carried out in the present study, the peak flows and water surface elevations have been estimated at various sections in the 9 km stretch of River Sabarmati in Ahmedabad city.