CHAPTER 5: EXISTING FLOOD MITIGATION STRATEGIES FOR MUMBAI

Flooding in the monsoons has been a common phenomenon in Mumbai. To deal with this annual event, the city’s disaster management framework includes some mitigation measures drafted out by the city’s planning commission and Municipal Corporation. The chapter looks at these measures and analyzes their shortcomings with respect to the intensity of the inundation faced by the city in the recent years.

1. Existing Flood Management Framework of Mumbai

Providing relief measures in the event of natural catastrophes such as floods has since long been one of the main goals of the disaster management department of the Mumbai Metropolitan Region as well as other states in India. The Central Government of the country, however, associates itself only with post-disaster relief measures and its response is determined by factors such as: “(i) the gravity of the disaster in question, (ii) the scale of the relief operation required and (iii) the requirements of assistance from the central government to expand the financial resources at the disposal of the State Government.” So far, the disaster management framework has been drafted for the country as a whole by the Central government of India. It consists of flood mitigation strategies as a part of its plan to deal with other natural and human induced disasters such as fires and earthquakes. The following report drafted in 2004 provides broad guidelines to exercise mitigation strategies for various kinds of disasters:

1.1. Disaster Management of India Report( 2004):

The following status report of the Disaster Management in India (2004) lists the salient features of the draft national policy on disaster management:

• The report adopts a realistic and holistic approach towards the management of various calamities.


• Every “department of the Central/State Government should set apart an appropriate portion of its funds, for specific projects tackling vulnerability reduction and preparedness” in the event of a disaster.
  
• Where a number of projects have been lined up for an approval from the government, the projects incorporating mitigation measures, in their plans, should be given priority over the other projects to be approved. These strategies should be integrated into the Government’s current mitigation programs.


• In order to be approved, each project in a disaster prone area should have disaster mitigation as an essential condition to be fulfilled. The project report should include a testimonial stating as to how the project tackles the issue of incorporating mitigation strategies into its design.


• Involvement of the general public and generation of awareness amongst the masses, essentially the susceptible sections of the population, should be stressed as an essential step towards sustainable vulnerability reduction. This is a vital part of the disaster management structure since the general public is the first responder to various calamities. Therefore, unless it is given authority and “made capable of managing disasters, any amount of external support cannot lead to optimal results.”


• A close interaction should be established between the “corporate sector, non-governmental organizations and the media,” in the city wide “efforts for flood prevention and disaster risk reduction.”


• Institutional framework with the right sequence of command should be developed to regularize the mitigation process. Also, the disaster managers at different levels of the government should be appropriately “trained to ensure a coordinated and quick response at all levels.”


• Additionally, during the emergencies, arrangements should be made to share resources such as power, food and funds amongst the states.


• A tradition of “planning and preparedness” is to be integrated into all sections of the government to build up their efficiency to deal with the disasters.


• “Relevant government departments should be established for handling specific disasters.”


• “The design of all the new constructions must comply with the relevant Indian standards.”


• All the vital buildings in flood prone zones such as hospitals, railway stations, airports/airport control towers, fire station buildings, bus stands and administrative centers should be checked for the extent of their susceptibility to disasters. If necessary, they should be strengthened or remodeled to deal with the expected disasters in the future.


• “The existing relief codes in various states of the country should be revised to be developed into disaster management codes and manuals.” This would regularize the “planning process with a particular emphasis on mitigation and preparedness.”


• The Government should extend co-operation with the other nations that are proficient in the fields of disaster response, preparedness and mitigation. The resultant mitigation measures should comply with the strategic objectives of the country.

It is observed, however, that the policies drafted in this report provide a general framework for all kinds of disasters for the entire country.Therefore, following the destruction left behind by city’s deluge in 2005; Mumbai’s governing authority appointed the Chitale committee. This committee formulated flood mitigation strategies specifically for the city of Mumbai and its surrounding region.

1.2. Chitale Committee Report:

The Chitale Committee’s recommendations to mitigate floods in Mumbai can be summed up as follows:

• Create Contour maps of all the water sheds in the region using tools such as GIS.


• “Stream Gauge the measurement of flow (1 for 200000 populations)–This should be based on the catchment area.”


• Install Automatic Rain Gauges: This would prove to be much more efficient in serving the purpose as opposed to the existing manual rain gauges currently deployed by the city, to measure the rainfall (Adjoining Figure).

Maintain Storm Water network –Clean the debris from the existing storm-water drains, remove obstructions, rehabilitate SWD and ban the use of plastic bags that usually block most of the drains in the city (Adjoining Figure).

• Cover the trenches carrying water pipes, drain pipes and electric cables before the advent of monsoon; this would prevent unwanted accumulation of rainwater.


• Plan additional covered outfalls for rainwater and install additional pumping stations at critical flood prone locations.


• Similarly, create more holding ponds and reservoirs to accumulate the rain water and regulate this water towards constructive use such as generation of power and irrigation of agricultural lands.


• Review and revise the earlier disaster management reports and make them adaptive to the current social, economic and climatic scenario of the city of Mumbai.

These policies would still prove to be insufficient, considering the causes of the floods in Mumbai and their consequences, stated in the previous chapters of the study. What is truly required is a flood management framework derived from a reference of the flood mitigation and management strategies successfully implemented in other regions and countries. Regions facing the issue of recurrent flooding have been essentially been chosen for the purpose of this review.

Thus, in the next chapter, this study conducts case studies of the best flood mitigation practices that have applied in other flood-prone regions around the world. These strategies shall eventually be used as guidelines to formulate and recommend mitigation policies pertaining solely to floods and particularly for the Mumbai Metropolitan region.