Drainage Management in an Urban Watershed under Climate Change Scenario using IWRM Concepts

Abstract

Surface water and ground water pollution becomes a critical factor in urban areas because having high density of population and infrastructure. Drainage management is very critical and final results is poor water quality status in natural streams when fails to manage the system. This paper aims to demonstrate the capability of developing a water balance model facilitating a quantified watershed management with incorporation of IWRM principles to give solutions for an urban watershed. Then watershed is to be divided in to sub watersheds as necessary in a spatially distributed manner by inspecting the stream network. After that water balance model can be developed considering rainfall, surface runoff, water consumption, return waste discharges of industries and domestic, pan evaporation values and dilution factors etc. Then possible solution can be proposed to achieve a satisfactory water environment for each sub watershed. Subsequently, the situation of growing domestic and industrial units by year 2025 can be evaluated after incorporating a solution for the present situation. In case of climate change, the three scenarios considered a decrease in rainfall of 7%, an increase of 8% in evaporation, a decrease of lowest rainfall and an increase in peak flow. The final output demonstrated the solutions suggested for the worst case scenario.