Urban and landscape design strategies for flood resilience in Chennai city

Abstract

Chennai, the capital city of Tamil Nadu is located in the South East of India and lies at a mere 6.7m above mean sea level. Chennai is in a vulnerable location due to storm surges as well as tropical cyclones that bring about heavy rains and yearly floods. The 2004 Tsunami greatly affected the coast, and rapid urbanization, accompanied by the reduction in the natural drain capacity of the ground caused by encroachments on marshes, wetlands and other ecologically sensitive and permeable areas has contributed to repeat flood events in the city. Channelized rivers and canals contaminated through the presence of informal settlements and garbage has exasperated the situation. Natural and man-made water infrastructures that include, monsoon water harvesting and storage systems such as the Temple tanks and reservoirs have been polluted, and have fallen into disuse. The main aim of this research is to seek how urban and landscape design can contribute to the prevention and mitigation of flooding in Chennai city. How can Blue-Green Infrastructure and community involvement create more resilience? How can we enhance and remediate existing structures to mitigate flooding? For this, we will investigate: What types of flooding affect the City? What are the natural and constructed water systems affected by floods? What is the function of the historical water infrastructures today? How can we adapt to storm water flooding and storm surges from the sea? What urban and ecological infrastructures, strategies, and policies can be implemented to prevent and mitigate future flooding? This thesis consolidates available literature and maps on Floods and after analysis of historic and contemporary maps and international case studies, suggests intervention measures at different urban scales, from micro to macro level to create resilience to floods in Chennai. Additionally, Urban Policy measures that can be implemented to support the proposed Urban and Landscape design intervention are recommended. It is anticipated that the lessons learnt from studying the city of Chennai will help other coastal cities develop resilience against floods.