DETERMINATION OF SAFE GRADE ELEVATION BY USING HEC-RAS: CASE STUDY MUTHA RIVER

Abstract

Flood is a naturally occurring disastrous event causing damages, losses and destruction to property, life and environment. Hundred millions of money are spent every year in flood control and flood forecasting. For construction of any structure near by a water body or in between a water body and for determination of safe levels of construction to protect structure from flood water, safe grade elevation is required. In order to evaluate or estimate, mitigate and handle the floods, the present paper presents a methodology for assessment of flood line to produce safe grade elevation by using River Analysis System made by Hydrologic Engineering Center (HEC-RAS) software which is predominately used in the field of hydraulic analysis for floodplain delineation. The general parameter affecting flood is runoff gauge, discharge, rainfall and land use as spatial data. This paper explains the use of the HEC-RAS for producing the safe grade elevation for Mutha River from its origin at downstream side of Kadakwasla dam till Mahtre Bridge. It explains the methodology to construct a table model and how to validate it. The methodology developed can be applied for regions if only predominant factors affecting the flood in that region is consider, to decide the best economical safe grade elevation for the building or structure near or on the river and would help in planning priorities prerequisites for managing flood efficiently.