India’s slums house tens of millions of people in conditions defined by overcrowding, inadequate sanitation, and uncertain legal status, yet they also contain thriving economies, deep social networks, and communities that have persisted for generations. The scale is staggering: India has one of the largest urban informal-settlement populations on Earth, concentrated in cities like Mumbai, Delhi, Kolkata, and Chennai. Understanding what drives people into these settlements, what life inside them actually looks like, and why they prove so resistant to policy fixes requires looking well beyond the surface imagery of corrugated tin and open drains.
Why Slums Keep Growing
The engine behind India’s slums is migration, and behind migration is a stark gap between rural and urban opportunity. In rural India, roughly 55 percent of households that migrate do so for employment-related reasons, driven by sluggish agricultural growth, limited non-farm work, and persistent poverty.1REAL CORP Repository. Smart Village as an Instrument to Curb the Rural to Urban Migration in India Cities pull people in with jobs, infrastructure, and the hope of upward mobility. But because affordable urban housing barely exists for the wages most migrants earn, they land in informal settlements where shelter can be improvised cheaply and quickly.
This pattern has repeated across decades. Each wave of industrial growth or construction activity in a major city draws fresh arrivals who cannot afford formal housing markets. The settlements they create fill floodplains, line railway tracks, and crowd into gaps between commercial buildings. Over time, these clusters densify and develop their own internal economies, schools, and social hierarchies. They are not temporary encampments; many Indian slums are decades old, with second and third generations born on the same patch of ground their grandparents settled.
The Tenure Problem at the Root of Everything
If one issue underlies almost every other challenge in Indian slums, it is the lack of secure land tenure. Most slum residents do not legally own the ground beneath their homes and have no formal protection against eviction. That insecurity has cascading effects: when you expect a bulldozer could arrive at any time, spending money on better walls, a proper roof, or a household toilet becomes a losing investment. Research on informal settlements has confirmed this pattern directly, showing that the anticipation of forced eviction or demolition discourages residents from gradually upgrading their housing, even when they have the financial means to do so.2Habitat International. Revealing invisible rules in slums: The nexus between perceived tenure security and housing investment
The consequences reach far beyond construction materials. Without recognized addresses, residents struggle to open bank accounts, enroll children in government schools, or access subsidized utilities. In Mumbai, a settlement’s official classification as “notified” or “non-notified” determines whether the city will extend water pipes and sewer lines to it. Non-notified slums, which lack any formal government acknowledgment, exist in a legal gray zone where even basic survival needs like drawing water or tapping an electrical line are treated as infractions. That criminalization of everyday life takes a measurable psychological toll, as we will see below.
Water, Sanitation, and the Daily Grind
Access to clean water is one of the sharpest divides between slums and the rest of urban India. Where municipal piped water does not reach, residents rely on informal distribution networks involving tanker trucks, shared standpipes, or hand-carried containers. Because of the difficulty of obtaining and transporting water through these channels, slum households often pay significantly more per liter than residents connected to municipal networks.3Health and Human Rights. Land security and the challenges of realizing the human right to water and sanitation in the slums of Mumbai, India The cruel paradox is that the poorest urban residents pay the highest price for the worst-quality water.
Sanitation is equally dire. A study of adolescent girls in an urban slum in central India found that only about 38 percent had access to an independent household toilet; roughly half relied on shared public facilities, and 9 percent practiced open defecation.4PubMed Central. A study of utilization of sanitary facilities by adolescent girls in an urban slum of Central India Research in Odisha’s slums showed that households forced to share latrines were more likely to resort to open defecation because the shared facilities were less likely to be functional, less clean, and more often contaminated with feces and flies.5PubMed Central. Shared Sanitation Versus Individual Household Latrines in Urban Slums: A Cross-Sectional Study in Orissa, India
For women, the sanitation gap is also a safety issue. A study of women in urban India found that those who perceived a community toilet as unsafe had more than three times the odds of avoiding it altogether, choosing instead to suppress urination or wait for darkness, with real urological and psychological consequences.6PubMed. Women ‘holding it’ in urban India: Toilet avoidance as an under-recognized health outcome of sanitation insecurity The government’s push to build more public toilets has helped in some areas, but a facility that feels dangerous after dark does not solve the problem it was built to address.
Disease, Density, and What COVID Revealed
High population density in slums turns everyday infections into fast-moving outbreaks. Larger household sizes mean more home-related contacts; the need to leave for work, water, and shared toilets means more outside contacts. Agent-based modeling of influenza spread in Delhi slums showed that the slum population sustained greater infection rates than surrounding neighborhoods under every intervention scenario tested, because of these unique contact patterns.7BMJ Open. Disparities in spread and control of influenza in slums of Delhi: findings from an agent-based modelling study
COVID-19 made the same dynamics impossible to ignore on a global stage. Analysis across multiple cities in the developing world found that neighborhoods containing slums consistently had the highest density of confirmed cases, establishing slums as the most at-risk urban locations during the pandemic.8PubMed Central. Spread of COVID-19 in urban neighbourhoods and slums of the developing world A separate study of Indian slums identified the core vulnerability factors: poor household conditions, inability to maintain physical distance, high concentrations of population, and frequent mobility in and out of settlements for work.9PubMed Central. Habitat vulnerability in slum areas of India – What we learnt from COVID-19? Telling people to isolate at home does not work when “home” is a single room shared by six family members.
Child Nutrition in the Settlements
Malnutrition among young children in Indian slums runs alarmingly high. A cross-sectional study of children aged 9 to 36 months in the slums of Belagavi found stunting in about 44 percent, underweight in about 25 percent, and wasting in roughly 11 percent.10PubMed Central. Prevalence and determinants of undernutrition in the urban slums of Belagavi: a cross-sectional study among young children A broader study comparing urban slums and rural areas in Maharashtra found a similar pattern: about 46 percent of under-five children were stunted and roughly 17 percent were wasted, and stunting was the most common form of undernutrition observed.11PubMed Central. Prevalence and determinants of undernutrition among under-five children residing in urban slums and rural area, Maharashtra, India: a community-based cross-sectional study
What makes these numbers striking is the comparison with rural areas. The Maharashtra study found that all three types of undernutrition were actually more prevalent in urban slums than in rural communities.12PubMed Central. Prevalence and determinants of undernutrition among under-five children residing in urban slums and rural area, Maharashtra, India: a community-based cross-sectional study This undercuts a common assumption that moving to the city automatically improves a family’s food security. In a slum, income may rise slightly, but so do living costs, and the conditions that promote childhood illness, contaminated water, overcrowding, poor sanitation, make it harder for children to absorb the nutrition they do receive.
The Psychological Weight of Informal Status
Physical health gets most of the attention, but mental health in slums deserves its own discussion. A mixed-methods study in Mumbai found that about 23 percent of slum residents scored high enough on a standard screening tool to suggest they were at serious risk for a common mental disorder such as depression or anxiety.13PubMed Central. The psychological toll of slum living in Mumbai, India: A mixed methods study Low household income and poverty-related factors were strong predictors, but so was something harder to measure: the social exclusion that comes with living in a settlement the government does not officially recognize.
Residents described a sense that their very existence was criminalized. Drawing water, using electricity, even occupying space felt like acts performed against the state rather than within it. That constant tension shaped a community identity built on a feeling of being excluded from the rest of the city, and it contributed to psychological distress independently of income.14PubMed Central. The psychological toll of slum living in Mumbai, India: A mixed methods study Addressing mental health in slums, in other words, is not just about counseling services. It requires changing the legal and social relationship between the settlement and the city around it.
Dharavi and the Informal Economy
It is easy to view slums purely as zones of deprivation, but that misses a vital dimension. Dharavi, Mumbai’s most famous informal settlement, has developed into a remarkably productive economic hub. Its informal economy revolves around four major sectors: leather processing, pottery production, waste recycling, and food processing. Roughly 15,000 small workshops are packed into the area, generating around 250,000 jobs and producing an annual output estimated between 600 million and 1 billion U.S. dollars.15Proceedings of the 3rd International Conference on Business, Management and Sustainability. The Development Logic and Practical Dilemmas of the Informal Economy in the Process of Urbanization: A Case Study of Dharavi Slum in Mumbai, India That output accounts for a substantial share of Mumbai’s external trade.
Dharavi is an extreme example, but the dynamic it illustrates is common across Indian slums. Settlements that look chaotic from the outside often contain intricate supply chains, specialized trades, and entrepreneurial networks that feed the formal city economy. The recycling workshops in Dharavi, for instance, process waste from the entire Mumbai metropolitan area, providing a service the municipal system does not come close to replicating. Any redevelopment plan that bulldozes a settlement without accounting for these economic ecosystems risks destroying livelihoods along with housing.
Electricity and the Cost of Informality
Electrification in Indian slums is better than many outsiders assume, but worse than in the formal city. Analysis of national survey data found that a typical slum household had about a 70 percent chance of being connected to the electricity grid, compared with roughly 80 percent for formal urban households and 50 percent for rural households.16Energy. Quantifying slum electrification in India and explaining local variation Those numbers have likely improved since the survey period, as India’s overall electrification rates have climbed, but the gap between slums and formal neighborhoods has proven stubborn.
Where grid connections are unavailable or unaffordable, residents resort to pilferage or pay inflated rates to illegal intermediaries who have tapped into the grid themselves. Research in Mumbai’s informal settlements documented a pattern where households without legal connections paid more to these middlemen than grid customers paid to the utility, while simultaneously contributing to the utility’s financial losses through theft.17Environmental Research: Energy. Watt’s fair in Mumbai: intermediaries’ impact on energy justice in informal settlements Electricity is not just about light and fans; it is an input for the informal workshop jobs that sustain whole neighborhoods and the motor-driven pumps that deliver water. Losing electrical access can cascade into lost income and lost water supply in a single stroke.
Heat, Housing Materials, and Climate Vulnerability
As Indian cities get hotter, slum residents face a disproportionate share of the danger. A study comparing indoor temperatures in Kolkata slum dwellings with rural village homes in West Bengal found that the hottest interiors belonged to slum homes built with cement walls and corrugated tin or clay tile roofs, while the coolest were traditional rural dwellings made of mud walls and thatch.18Building and Environment. Indoor heat conditions measured in urban slum and rural village housing in West Bengal, India The urban heat island effect combined with heat-absorbing construction materials created conditions where slum interiors were hotter than outside air throughout the day and particularly at night, when the body normally relies on cooler temperatures to recover.
For elderly residents, the consequences are severe. The same research team found that elderly people living in the Kolkata slum were roughly four times more likely to experience dangerous heat index levels compared with elderly villagers in rural areas.19PubMed. Individually experienced heat stress among elderly residents of an urban slum and rural village in India Access to fans or coolers can mitigate some of that risk, but it depends on reliable electricity, which, as noted, remains precarious. As extreme heat events become more frequent across South Asia, urban slum populations are among the least equipped to cope.
Gender Gaps in Access and Opportunity
Nearly every disadvantage in a slum is amplified for women. The digital divide offers a clear example: a cross-sectional study in New Delhi slums found that women were about half as likely as men to own a mobile phone and less likely to have internet access.20PubMed Central. Gender and the Digital Divide Across Urban Slums of New Delhi, India: Cross-Sectional Study In an era when government services, job listings, and even school enrollment increasingly move online, that gap translates directly into reduced opportunity.
Financial access follows a similar pattern. Research on women borrowers in Delhi and Mumbai slums found that despite government efforts to expand formal banking, informal credit remained the preferred source for most women.21Gender in Management: An International Journal. Formal vs informal demand for credit by women in urban India: a comparative study in slums of Delhi and Mumbai Microfinance institutions that do operate in slums often use room ownership as a hidden selection criterion for loan approval, favoring applicants who own their dwelling over renters, since ownership signals stability and lower default risk.22Margin: The Journal of Applied Economic Research. Creditworthiness of a Borrower and the Selection Process in Micro-finance: A Case Study from the Urban Slums of India This means the poorest residents, those most likely to be renting, are systematically screened out of the programs designed to help them.
When Redevelopment Makes Things Worse
Slum rehabilitation housing is often presented as the solution: demolish the settlement, build high-rise apartment blocks, and relocate residents into modern units. In practice, the results are more complicated. A study of women relocated from Mumbai slums into rehabilitation housing found that the move radically changed daily routines around cooking, childcare, comfort, and work. Poor design of the new buildings and the loss of outdoor communal space drove up electricity use and living costs across every surveyed household.23Energy Research & Social Science. Gender, domestic energy and design of inclusive low-income habitats: A case of slum rehabilitation housing in Mumbai, India
Women bore the brunt of these changes. Higher costs forced many into low-paid jobs or informal work, creating a cycle in which time poverty reduced their ability to pursue education or build social capital, which in turn locked them into the same low-wage work.24Energy Research & Social Science. Gender, domestic energy and design of inclusive low-income habitats: A case of slum rehabilitation housing in Mumbai, India Rehabilitation schemes that look like progress on paper can deepen the very inequalities they claim to address when they are designed without input from the communities being moved. The lesson from Mumbai is that housing is not just walls and a roof; it is proximity to work, access to communal cooking spaces, outdoor areas where children can play while parents earn, and the social infrastructure that makes daily survival possible. Removing all of that in the name of modernization can leave residents worse off than before.