Floods and storms are natural: a factor that must be stressed. The crisis arises when these floods take their toll on human life and property. The floods that swept over Mumbai in the monsoon of 2005 and more recently in 2009 in various parts of India, were the worst to be recorded in the city’s history of flooding. As far is Mumbai is concerned, the cause of this disaster was primarily the lack of sufficient drainage to help let out the floodwaters; this was further compounded by a high tide. The result was a city-wide inundation that battered the life and property in Mumbai. The event rendered the city dysfunctional by crippling its basic essential utilities and public means of transportation which are the lifelines of the city. This episode, that left a trail of massive destruction in Mumbai and its surrounding region in 2005, can be termed as a case of urban flash flooding. However, the probability of its recurrence in the future cannot be denied and this has been proven by the moderate floods that the city witnessed in the monsoon of the year 2006 as also by the ones that destroyed settlements in various parts of India, in 2009. The fact that global climate is changing largely contributes to this prospect of recurring floods. But, whether these floods would mainly result from continuous and heavy downpours bears some uncertainty in the view of the scientists who have been scrutinizing the world-wide change in climate patterns. Nevertheless, they believe that the global climate change may result in shorter but more intense monsoons in India. Likewise, these experts also claim that the melting of the ice caps at the poles and the vast reclamation of land from the sea, for the future expansion and urbanization of land, have substantially contributed to the rise in the sea-levels world-wide. Thus, in the event of a high tide or heavy rains or both, coastal areas such as Mumbai would be highly vulnerable to intense flooding, more often. It thus becomes inevitable for the governing and planning authorities of such coastal regions to include flood mitigation policies as an integral part of their general development framework.
Following the devastation left behind by the floods of 2005, the state government has been working towards minimizing the adverse effects of the floods by devising a flood mitigation framework for the city of Mumbai and its surrounding region. However, the destruction caused in the city by the moderate floods of 2006 is testimony to the fact that the flood mitigation mechanism, currently adopted by the city of Mumbai, is inefficient in curbing the intensity of the floods and their distressing consequences.
Therefore, this study makes an attempt to formulate and recommend policies from a planner’s point of view. The prime aim of these recommendations is to revise the existing flood mitigation structure of Mumbai as well as to suggest planning policies that can guide the future development of the city and curtail the adverse effects of the floods. At first, this study examined the probable causes for the intensity of the inundation in the city of Mumbai, after which it scrutinized the city’s presently deployed flood mitigation system to identify its shortcomings. Subsequently, this research conducted case studies to examine the role of planning in flood mitigation. In addition to an extensive review of Mumbai's history related to flood management, four additional regions are studied to reveal the success and failure of different mitigation strategies. These include New Orleans, Delaware, South Africa, and Bangladesh. Also, existing literature was examined in order to develop a comprehensive understanding of the best practices planners can utilize for proactive flood mitigation.
This report is organized as follows. An overview of Mumbai's geography, demographics, and planning history is discussed in Chapter 2. This is followed by an extensive analysis of the severe flooding in Mumbai in 2005 and 2006. Chapter 3 discusses the specific factors that influenced the severity of the flooding, including both natural and man-made causes. A review of the existing flood mitigation strategies in Mumbai is discussed in Chapter 5, while certain flood mitigation strategies not been addressed in the case-studies but crucial for the city of Mumbai are discussed in Chapter 6, through a review of literature about the best practices to manage floods. Based on this research, Chapter 7 recommends planning policies to mitigate the recurring inundation in Mumbai. The results of this research indicate that; The flood mitigation framework for Mumbai has to include planning policies suggesting more preventive measures as opposed to only post-flood relief measures. To achieve this, the policies should use sustainable development strategies as its basis to plan the future expansion of the city. Also, improving the existing infrastructure, to withstand floods, should constitute an essential part of the city’s flood management plans. Lastly, a proper co-ordination between the various flood management bodies is also essential to effectively implement the mitigation strategies as and when required.
While, this blog mainly discusses flood mitigation strategies for Mumbai region, the solutions are pretty much applicable to any flood affected region in the world.