A Feasibility Analysis on New Drainage Channel to Control Flooding in Southwest Chennai Using Hydraulic Model

Abstract

Flood Management plays a major role in minimizing the socio-economic loss in a watershed. In the urban context, flood is due to uncontrolled settlements of migrated population along the length of surplus carrying channels. This study focuses on feasibility analysis of existing drainage channel and proposed drainage channel network as structural management measure for a watershed, proposed by public work department of Chennai to reduce the impact of flood. In this study the hydrological model (HEC-HMS) is used to determines the discharge for a particular rainfall event within a watershed, this determined discharge of watershed and channel characteristic is given as input data to the hydraulic model (HEC-RAS) to simulate the movement of flood water through the hydraulic structure and calculates inundated areas around the urban storm water drainage network within a watershed. From the result it is quantified that the inundated area is 130.48 hectare for existing drainage channel condition and for proposed drainage channel condition the inundated area reduced to 32.35 hectare. However, the result shows that almost 70% of area under inundation is reduced after implementation of proposed drainage channel.