CHAPTER 1: INTRODUCTION

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.

Disaster management at a glance

Although there is no specific model solution to deal with a disaster such as floods, all the case studies unanimously state that any disaster mitigation mechanism has to be a united and synchronized process, and a few specific elements will be universally applicable to any form of disaster:

A disaster management framework is typically a three-fold system, consisting of:
1. Pre-disaster mitigation measures
2. Post-flood mitigation measures and
3. Input of the Government and Private sector in the disaster mitigation framework

1. Pre-disaster mitigation measures:
Floods can be effectively contained by collecting the data about past floods and the location of their occurrence. The data collected can then be used to plan policies that guide the future development of the city such that the adverse impacts of floods and the vulnerability of the settlements to the risk of inundation are considerably minimized. This principle could be further expanded to zone the flood prone areas to the limit development in these areas and thereby substantially contain the losses incurred from floods. In such a scenario, the government may use its discretionary powers to acquire the land in flood-prone areas and thus prevent development on it. Flood-induced losses can also be reduced at a micro-level by integrating flood-mitigation specifications into the design of individual buildings and their supporting infrastructure such as the drainage systems. These specifications can be successfully implemented by mandating them as a part of acquiring the building permit. Also, a regular maintenance of the existing infrastructure, especially the city’s drainage system is extremely crucial in this regard. In addition, deploying flood control devices at strategic points that serve as inlets for floodwaters also serves as an effective flood mitigation strategy. Floods may not be avoidable. But their adverse impacts can be reduced by preparing the flood-prone areas, in advance, to deal with the disaster. This can be achieved by precisely predicting the occurrence and intensity of the floods with the help of modern technology such as automatic rain-gauges, satellite images, GIS maps and sensors installed at critical flood prone points. These equipments can serve as warning devices to prepare the settlements in the flood-prone areas for the impending floods. Also, the areas where floods are most likely, institutions such as schools should be designed to provide shelter and sanitation facilities to the victims in the event of floods. Also, the hospitals in such areas should be well equipped to deal with various flood related casualties. Above all, the citizens in the flood-prone areas should be educated to deal with flood-related casualties to prevent chaos in the event of inundation. The process should include, training them to operate the in-place flood control devices and conducting periodic safety-drills;

(i) to help the citizens remain alert for the disaster at all times and

(ii) to ensure the proper functioning of flood-control devices whenever the need arises.

2. Post-disaster mitigation measures:
Post-flood mitigation measures come into the picture after the occurrence of floods. They broadly include the rescue of the flood victims, evacuation of the flooded areas, providing the affected with prompt relief measures, the rehabilitation of the victims as well as the reconstruction of the property destroyed by the floods. In order to ensure the prompt evacuation of the victims from the flood-stricken areas, it is essential that the city is planned to provide sufficient evacuation routes. At a micro-level, the evacuation routes should form an important part of the design of individual buildings, thus reducing flood-related losses to a considerable extent. Likewise, timely and quality relief measures can be guaranteed by the city’s governing authorities by way of promoting cooperation with other nations that are proficient in the responding to disasters. These measures should comply with the city’s strategic goals and objectives, so that they blend into the local context.

After the occurrence of the floods, the rehabilitation of the flood victims and the restoration of the services and utilities have to be of primary significance to the city authorities, in order to restore the normalcy of the city. Based on the priority, the strategies in this regard can be categorized as: a) short term; and b) long term in nature.

(a) Short-term Strategies: These include the immediate response of the city authorities to restore various services for the safety and health of the affected.

(b) Long term Strategies: Long term strategies should not only entail reinstating the environment existing before the event, but should also improve the environment to withstand further disasters. To do so, the strategies have to consider factors such as vulnerability and risk analysis.

3. Input of the Government and Private sector in flood mitigation

The Government should serve as a one-point contact between the various city agencies such as the weather bureau, the telephone department, other media such as radio and television, electricity department, civic amenities department, port authorities and the roads department, to facilitate communication between them in the event of floods. The government should also distribute the process of making decisions to the local administrative levels to ensure prompt action, transferring of financial resources and enhancing the technical expertise of the flood mitigation team. The private sector can also significantly contribute to the flood-mitigation process by providing financial help and technical expertise. To bring this about effectively, the government should provide comprehensive regulations, such as just compensation, whereby private agents are enticed to be enthusiastically participate in the flood mitigation process. Thus, a prompt and strategic application of the various sections of this flood-mitigation framework, as and when required, can substantially reduce the losses incurred by the city of Mumbai due to its recurring inundation.