Thursday, July 23, 2009


This chapter focuses on Mumbai’s geography, its planning history and its demographics. It thus provides a better understanding of what has given rise to the recurrent deluge in the city.

1. Physical Features
The Mumbai Metropolitan region is located in the tropical zone, on the west-coast of India. It is bordered on its three sides by sea: the Arabian Sea to the west and south and the Harbor Bay and the Thane Creek in the east. The Mumbai region covers an area of 600.71 square kilometers. An aerial view (Adjoining figure) of this region shows a tapering island, about 25 miles long and two to seven miles wide, connected to the region’s mainland towards the north-east and separated by an estuary. At present, “the region includes the original group of islands of Mumbai, and a large part of the island of Salsette. The Salsette-Mumbai island creek and the Thane Creek (Adjoining figure) together separate it from the mainland.”

The area is just about 10 to 15 meters above the region’s mean sea level, while at some locations the topographical elevation is barely over the level of the sea. The Backbay and Bandra reclamation are the two of largest parts of Mumbai, reclaimed from the Arabian Sea. The soil cover within Mumbai city is mostly sandy while it is largely alluvial in the suburbs. Until about a decade ago, the region has had a year around moderate climate, with the mean temperatures ranging from 75-90°F. On an average, it has had an annual rainfall ranging from 230-240 millimeters, which is one of the highest to be recorded in the entire country. As is the case with most of the islands around the world, this island region also consists of a central mountainous area. In Mumbai, this hilly consist of the Vihar Lake and Powai Lake that serve as reservoirs to store the rainwater. In the past, the excess rainwater from these reservoirs overflowed and drained through the city’s natural drain, the Mithi River, into the Mahim Creek and finally into the Arabian Sea.

2. Regional History
The history of the Mumbai region give details of the socio-economic factors that have led to the physical development of the city as it is in the present day. Since the advent of civilization, urbanization is related to proximity of water sources such as the sea, rivers and lakes. As Donald Geis and Barry Steeves mention in their article, “development along seacoasts and rivers has been a product of a logical evolution.” Access to a water-source is vital for transportation, economic development, defense, recreation, social amenities and sanitation. The strategic importance of each of these factors has changes with passing times. However their linkage and the need for each of these factors to be close to a water source, has persisted. Human settlements have taken advantage of the nature on both, economic and social front. The need for water has led to humans occupying low- lying lands that are prone to flooding. This has led to the rapid urbanization of these areas, as is the case of the metropolitan region of Mumbai, formerly known as Bombay. The city has proven to be the proverbial “melting pot” for people from various cultural, ethnic and economic backgrounds. With an advantage of being located next to the Arabian Sea, the region has fostered international trade in the past centuries. In the past, it became a favorite hub for various invaders including the Moguls, the Portuguese and the British among others.

In 1534, the Portuguese, who had by then acquired many important trading hubs along the west coast of India, forcibly took Bombay away from the Moguls. They also guarded this possession by constructing forts at Sion, Mahim and Bandra. Until the 1660s, Mumbai was made up of seven islands, comprising of Colaba, Mazagaon, Old Woman's Island, Wadala, Mahim, Parel, and Matunga-Sion; these islands were eventually connected in various phases, by reclaiming land from the sea. In 1668, Queen Victoria, the ruler of India leased out these islands to the English East India Company. The Company, which then operated from the port of Gujarat, a port to the north west of Bombay, was in search of a deeper port to facilitate the docking of larger vessels and it found the islands of Bombay apt for this use. The sea-routes at Worli, Mahim, and Mahalaxmi transformed the soil cover linking the islands into marshes and thus made Bombay, an extremely unsanitary place at that time. Many commuters traveling from one island to the other by boat lost their lives during the monsoon storms. To end this crisis, in the years 1784-1845, the seven islands were linked in phases by reclaiming land and connecting the various islands to form a network of roads. With the British invasion, also came the rapid development of the city’s transportation infrastructure. On the April 16, 1853 the first railway line of India, began operating for 21-miles, between Bombay's Victoria Terminus and Thane. The opening of the Suez Canal in the year 1869 brought the Western world closer to Bombay and the city prospered. Following the success of this venture, more projects were launched to reclaim more land and build more roads, rails and wharves.

3. Population Dynamics
Bombay started drawing fortune seekers by the thousands. The population of the city had risen from 13,726 in 1780 to an astonishing 644,405 in 1872, within a century. By 1906 the population of Bombay was as much as 977,822. The expansion of Mumbai continued until present times and the city has now developed into India’s financial capital. As India’s center of commerce, financial institutions like the, Bombay Stock Exchange, National Stock Exchange, Reserve Bank of India, and other major banks are housed here. It is also home to numerous refineries, power plants, residential and commercial developments and port facilities. Additionally, tourism is one of its important industries, especially along the coastal zone. With one of the world’s most promising economies, it witnesses a large influx of population every day. This influx comes from the neighboring cities, states and even from the neighboring countries, either legally or illegally. As of the 2001 Census, Mumbai had a population of about 16.37 million, which is expected to shoot up to 25 million by 2025 and surpass 35 million by 2031.The population density of this city also exceeds that of most of the other metropolitan cities in the world. Mumbai has a population density of 27209 persons/sq. km, compared to a figure of about 900 persons/sq. km, in Sydney, Australia. Adjoining figure shows the pattern of population growth, for the city of Mumbai and the Mumbai Metropolitan Region for the years 1971-2001, with projections for the years 2001-2031. The steep growth that is depicted in the accompanying graph demanded more space to be accommodated. This led to the destruction of the mangroves and extensive reclamation of land from the sea. A detailed analysis of these events is performed in the following section of this chapter, starting with a review of the city’s growth pattern and resultant history of its planning.

4. Growth Pattern and Planning History
The demand to house the overwhelming population growth has led to Mumbai reclaiming more land from the sea, rivers and marshy lands. Nariman Point; the city’s southern most tip, the whole of Marine Drive, large parts of Colaba, Oval Maidan and most of Ballard Estate have been reclaimed as the Backbay Reclamation. Low-lying areas like Haji Ali and Mahalaxmi, that were originally swamps, were also reclaimed under this scheme for development. A lot of this development is in the form of vulnerable, informal and often illegal settlements, such as the ones seen on the banks of Mithi River. “Nearly 65% of the city’s population is known to reside in illegal or informal settlements. According to the 1985 census, the city had nearly 2335 slum settlements, which has multiplied to almost five times that number in the past two decades or so.” The governing authorities have added to this plight by permitting development in the areas, which earlier served as natural drains for the city. This blocks the natural flow of water.

Even the city’s lake beds are not spared. The Mithi River is inundated because its course has been reduced to almost 1/3 of its original width due to the excessive reclamation of land. Infrastructure facilities such as the Bandra-Worli sea-link and the extension to the Santacruz International airport have been largely developed on this reclaimed land.Thus, the uncontrolled construction and concretization of land on either of its sides has left the Mithi River with no “flood-banks.” The Mumbai Metropolitan Regional Development Authority (MMRDA) has also been largely responsible for the reclamation along the Mithi River to facilitate the construction of the Bandra-Kurla Complex; a commercial hub in the city's northern suburbs, planned to dissolve the further concentration of offices and commercial activities in South Mumbai. It covers about 370 hectares# of low-lying land on either sides of the Mithi River, the Vakola and the Mahim Creek. The area has been massively reclaimed and concretized. The entire process has continued until the present day and the city now has the lowest ratio of open land available per person, compared to any major metropolis.

The city’s “Natural ‘sinks’ for the excess rainwater such as open grounds – with vegetation, forests, mangroves, marshes have been reclaimed and developed, and are therefore, now in short supply.” The Thane Creek has also witnessed some major, unchecked reclamation. At the local level, the region’s planning authorities have tried implementing the Coastal Regulation Zoning (CRZ), “which prevents development within 500 meters from the high tide line of the sea.” However, the developers pay no heed to this regulation and continue with their land-filling exercise.

Moreover, the faulty reports made by the state government’s environmental authority; the Center of Earth Sciences (CES), deleted various areas from the jurisdiction of the Coastal Regulation Zone (CRZ). The report legally permitted developers to develop rashly in the areas that fall in the coastal flood plains. The results of this report reflected in the Mumbai development plan 2005-2025. The plan relaxed the laws in CRZII and CRZIII (coastal zones which have been granted concessions for development depending upon the proposed land-use), in order to meet the extra demand for almost 15-20% more housing. These regulations should be reviewed again and updated to deal with the city’s current climatic conditions and the change in the amount of annual rainfall. The city’s rapid urbanization has also led to a fast reduction of the mangroves in the city. Figure 9 shows a graphical representation of the area-wise reduction of mangroves in the Mumbai Metropolitan region between the years 1925-1994.
Another alarming atrocity on the environment is the quarrying of the hills to make land available for the expansion of the city. Extensive, legal and illegal quarrying of the hills in and around Powai has made the hill remnants extremely unstable, making them highly vulnerable to collapse. The hill slopes have been cleared off vegetation to maximize the construction potential and this has added to the risk of landslides in this region.
In addition to a loss of the vegetation, quarrying also results in the destruction of the earth’s natural, permeable surface that has an innate capacity to retain and absorb the rain water.

5. Current Efforts to Save the Banks of Mithi River
There have also been certain measures taken up by the MMRDA to contain the alarming decrease in the natural sinks in the city. To make up to the natural drainage lost from the extensive reclamation of the Mithi River, the MMRDA has developed, what is now known as the Mahim Nature Park. Until about 30 years ago, this site was used as a dumping ground for the city’s garbage. Most of this garbage overflowed into the Mithi River, obstructing its natural flow. Towards the end of the 1970s, this area, stretching approximately over 37 acres in the Bandra-Kurla Complex, was ecologically reinstated, to be developed as a nature-friendly park by the MMRDA, in partnership with the WWF-India, an environmental conservation organization. Located on the southern bank of Mithi River (where the river flows into the Arabian Sea at the Mahim Bay as one of the major drainage outfalls of Mumbai), this small forest-like development can be described as a miracle of sorts. The park essentially serves as a green breather for a pollution-stricken city and a sanctuary for birds of various species and other rare insects. In addition, this park also serves as a natural sink with a permeable soil cover that absorbs excess rain water and drains the remainder of it into the bay.
However, the park covers only a small fraction of the area covered by the Bandra-Kurla Complex and is not sufficient to serve the entire city. This is because, in addition to the Mithi River, Mumbai largely depends on the storm water drainage system laid out throughout the region. A detailed layout, of the city’s drainage system and its contribution to the inundation of the city during the annual monsoons, is discussed in the following chapters.


  1. Hello!
    You have posted in the blog above an image of the Bandra Kurla Complex and the course of the Mithi River, along with it's original course mapped as well. Where did you get the drawings/maps of the same?
    I'm studying that very same site for an architectural project and would appreciate if you could help me with the geographical history of the area, any drawings or readings that you have or know of.
    Thank you :)