India lives in its streets.

Nowhere is that more evident than here at Dhobi Ghat, a sprawling open-air compound under Mumbai's Mahalaxmi bridge where the city's dirty laundry comes to be washed, dried, ironed, starched, and returned. All in a day's work, and not a single sock goes missing.

Each morning, some 10,000 dhobis or washermen rise with the sun to collect laundry from the southernmost tip of Mumbai to its northernmost suburbs and bring it here. The dhobis work for 14 to 16 hours to wash 100 to 200 articles of clothing each day. The dull thud of laundry slapping against the cement washboards can be heard every day of the year, with the exception of the Hindu festival Holi.

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From dawn to dusk, almost all 826 of the original takils (cement stalls) are occupied by cleaners in various stages of undress in the stifling heat. Many of the dhobis work in a wash-dry tag team of father and son, earning 500 to 1,000 rupees ($10 to $20) from each stall on an average workday. These men, aged 14 to 65, and a handful of women, collectively handle more than a million articles of clothing a day. Their clients include the well-to-do as well as hospitals, hotels and the Indian Railways. "This is a dhobi community. We share the good, the bad, the wet, the dry," says Sujil Kumar, 28.

Together with kolis (Mumbai's fishermen caste), dhobis are among the oldest occupations in India. But in recent years, this bulwark of tradition has come under siege by an unlikely modernizing force: the Brihanmumbai Municipal Corp., the city government. The BMC and the Dhobi Co-op Society, a de facto labour union for the dhobis, have been embroiled in a legal dispute that pits the washermen against demands from developers.

The source of the conflict is simple: This patch of land in the heart of Mumbai where the dhobis ply their trade is only 40,000 square feet, about the size of two Shoppers Drug Mart stores – yet it's worth a staggering 10 billion rupees ($220-million) and is perhaps the last meaningful chance at large-scale development in Mumbai's land-starved high-density financial district.

This looming battle between tradition and profit in the heart of Mumbai is one of many such being fought in India, where the corporate titans of Tata Motors Ltd. and Infosys Ltd. clash with a way of doing business in which bribes are routine and many executives still consult astrologers.

India has enabled the successes of corporate giants such as Reliance Industries Ltd. and Wipro Ltd. It is reputed to be home to the largest number of billionaires in Asia. But India is also a nation still bound by the caste order and crippled by poverty, where the government estimates 93 per cent of its business is conducted under the table.

It's a city of dichotomies. Along the seawall of this island city, women in burkas pass others wearing spandex and running shoes, and ashram gurus can be seen playing Angry Birds on their iPhones. In Mumbai, institutions such as Dhobi Ghat exist alongside bustling railway tracks and looming skyscrapers.

This division is especially evident in the Mumbai tower known as The Imperial, the world's tallest residential building, where the first 20 floors are given over to former slum dwellers (thus meeting the municipal code) and from the 21st floor onward, well-to-do industrialists, foreign expatriates and Bollywood stars live in luxury condos.

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The city's current property bubble can be traced back to 2005 when the government opened up the real estate market to foreign direct investment. Today, land in Mumbai is worth more than land in Manhattan.

Mumbai's developers believe that it is only a matter of time until the BMC gives in to the demands of the commercial real estate lobby and forces the dhobis to sell their land.

The dhobis believe otherwise. At the makeshift office in the heart of Dhobi Ghat, Santosh Kanojia, the president of the Dhobi Co-op Society and a former dhobi, gingerly hands over a copy of the 1958 collective agreement with the city. The well-worn document seems to support what Mr. Kanojia has been arguing over multiple cups of chai: both law and custom stipulate that the dhobis have full ownership over the laundry plots.

But the BMC has made no attempts to stem the tide of encroaching squatters at Dhobi Ghat and the dhobis fear that could lead to eventual appropriation of the site and a sale.

Meanwhile, a continuing legal row with government over upkeep of the land has meant that essential services continue to go overlooked: Open sewers and frequent power cuts attest to government neglect.

Asked why they choose to stay despite the subpar working conditions (washing slats double as beds), Mr. Kumar shrugs and answers, "there is always a job here."

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Pressed, he says that his dream is to provide a better life for his children. When asked how his son is to break the caste cycle, Mr. Kumar gives the classic Mumbai refrain: "Depends on luck."

To be a dhobi is to belong to a subcaste: it is your livelihood, identity, and clan all rolled into one. In India's deeply entrenched society, dhobis have known no other calling, no other home.

It is not a world of meritocracy or modernity, but one of heritage and of tradition. There is no room for new dreams or desires, only routine. "[I] just wake up in the morning. Do job, wash. Make food. Eat food. Go to bed. Again. Repeat," Mr. Kanojia says.

Sachin Dama, or Don as he is known, is a 14-year-old who is the self-proclaimed king of Dhobi Ghat. When he is not busy fetching chai or chewing paan (a stimulant made from betel leaves), he is the youngest member of the underground group whose main purpose is to extort money from the 1,000 or so foreign tourists a day who are drawn to Mahalaxmi for a slice of authentic Mumbai culture.

Unlike his brother and father, Don is eager to leave Dhobi Ghat behind. He represents a new generation of dhobis who would much prefer to be replaced with washing machines (up to 200 have been installed so far), sell the plots, make some fast cash, and set off into Mumbai's congested horizon.

"My father is a dhobi, brother is a dhobi, grandfather was a dhobi," he says. "But I don't want [to be one]" whispers Don.

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Still, stay or go, the BMC is caught in a bind, fearful of being accused of upsetting centuries of tradition. The Dhobi Ghat has become something of a symbol for Mumbai. A film by Aamir Khan, Bollywood's patron saint of the dhobis and a frequent customer of their service, was released to rapturous applause earlier this year ( Dhobi Ghat made its debut at the Toronto Film Festival in 2009 under the distribution-friendly title, Mumbai Diaries). As the largest open-air laundry in the world, it won Guinness World Records fame for "the most people hand-washing clothes simultaneously at a single location" in March.

And, while once the territory of migrants from Uttar Pradesh, the Dhobi Ghat is now populated by migrants from all states across India – Gujaratis, Telugus, Biharis, and the original Marathis. The religious and ethnic make up is roughly 50-50 – half Hindu, half Muslim, causing Mr. Kanojia to say, "we are the symbol of India."

Besides, he says, "Labour is cheap in India. Washing machine come, washing machine go. Dhobi stay. Everyone needs their laundry washed."

Speculation about its future persists. But for now, the sea of colourful saris is faithfully hung out to dry daily, an art form amid the stifling humidity of Mumbai. The promised land remains a riot of colour.