Slums, Slum Development and Associated Problems

• A slum is a densely built urban area of poor-quality, overcrowded housing with inadequate water, sanitation and services, and often insecure tenure.
• Slums are a by-product of rapid, unplanned urbanisation. Cities grow faster than land, housing, jobs and services can be supplied to the poor.
• In 2022, 1.12 billion people (24.8% of the world’s urban population) lived in slums or informal settlements. In India, Census 2011 counted 6.55 crore slum dwellers, about one in six urban Indians.

Slums: Definition, Concept and Characteristics

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Definitions

• UN-Habitat defines a slum household as one lacking one or more of five conditions:
  • Safe drinking water: shared taps, tankers or unsafe sources raise water-borne disease.
  • Improved sanitation: no private or adequately shared toilet.
  • Sufficient living area: more than three persons per room counts as overcrowding.
  • Durable housing: walls and roofs of tin, plastic, mud or scrap that give little protection from weather and hazards.
  • Secure tenure: no legal protection against eviction.
• India, legal definition:
  • The Slum Areas (Improvement and Clearance) Act, 1956 lets governments declare as slums areas whose buildings are unfit for human habitation.
  • The causes may be dilapidation, overcrowding, faulty arrangement and design, narrow or faulty streets, or lack of ventilation, light and sanitation, where these are detrimental to safety, health or morals.
• Census of India (2011) recognises three types in all statutory towns:

• The National Sample Survey also counts non-notified slums: compact clusters of at least 20 households of poorly built, crowded tenements. Its 69th round (2012) estimated 33,510 slums in urban India.

Slum, Squatter Settlement and Shanty Town

• A slum is defined by its condition: poor housing and services. It is usually older and more stable, and is often found in the inner city.
• A squatter settlement is defined by its legal status: dwellings built without permission on land not owned by the builders. Squatter settlements are often newer and on the periphery, along railway lines or on vacant public land. They grow by overnight invasion or by gradual accretion.
  • They range from 10–20 dwellings to agglomerations of thousands of houses, and their services fall below the adequate minimum.
• A shanty town is defined by its fabric: makeshift huts of cardboard, tin, sacking and scrap. It is typical of mass rural–urban migration in the developing world.
• In practice the three overlap: many squatter settlements become consolidated brick slums over a generation.
• Local names:
  • In India: bustee (Kolkata), jhuggi-jhopri (Delhi), chawl and jhopadpatti (Mumbai), cheri (Chennai).
  • Abroad: favela (Brazil), barriada (Peru), kampung (Indonesia), gecekondu (Turkey), bidonville (French-speaking North Africa).

Characteristics

• Physical:
  • Unplanned, informal growth on marginal land: riverbanks, railway lines, drains, hill slopes and vacant public land.
  • Very high densities, with one- or two-room homes and narrow lanes.
  • Walls of mud or brick and low roofs of corrugated sheet, tin, bamboo matting, polythene, sacking or thatch, often with no windows.
  • Poor ventilation and light.
• Environmental:
  • Open drains, stagnant pools and heaps of waste.
  • Few open spaces and contaminated water.
  • Shallow hand-pumps serve slums without piped water, and often stand in stale pools. Waste seeps down and contaminates the groundwater they draw on, bringing dysentery, diarrhoea, typhoid and jaundice.
  • Shallow pit latrines overflow, and nullahs used as open toilets breed flies and mosquitoes.
• Services:
  • Shared taps and community toilets.
  • Irregular electricity, and poor schools, health care and transport.
• Economic:
  • Mostly informal work: construction, domestic service, vending, home-based manufacture, recycling.
  • Low and irregular incomes.
  • Many slums are also production centres. Dharavi’s leather, pottery, garment and recycling units are an example.
• Social:
  • Largely migrants and their descendants, often grouped by caste, region or religion.
  • A sex ratio of 928 females per 1,000 males in 2011, below the national 943. Literacy was 77.7%, against 85.4% in urban India.
  • Strong informal networks.
  • Stigma and exclusion from the formal city.
• Legal: insecure or no tenure, which brings constant fear of eviction and exploitation by landlords, “slumlords” and land mafias.

Types of Slums

• By location in the metropolis:
  • Inner-city tenements: Mumbai’s chawls, Delhi’s katras in the walled city, Kolkata’s bustees.
  • Corridor slums along railway lines and nullahs.
  • Riverbank and floodplain slums: the Yamuna pushta in Delhi, the Cooum in Chennai.
  • Hill-slope slums in Mumbai and on Rio’s favela hillsides.
  • Peripheral squatter colonies near new industry and construction.
  • Urban villages: Delhi’s lal dora areas.
  • Resettlement colonies that decay into slums: Bawana and Savda Ghevra in Delhi.
• By prospects (Charles Stokes, 1962):
  • Slums of hope: newcomers on their way up the urban ladder, improving their homes over time.
  • Slums of despair: people trapped by poverty, caste, disability or age, with deteriorating conditions.
• By legal status: notified, recognised and identified (India); authorised and unauthorised.

Slums in the Indian Context

• In India, slums are closely tied to informal housing and unauthorised construction. They reflect the mismatch between fast urban population growth and slow provision of land and infrastructure.
• They are not only the homes of new migrants. Many are decades old, with second- and third-generation residents, brick houses, shops and workshops.
• They supply the city’s construction workers, domestic workers, drivers, vendors and waste-pickers. The formal city depends on this labour but does not house it.
• Despite poor conditions, slums often give better access to work, schools and hospitals than the villages migrants left. This is why they keep growing.

How Slums Develop

• John F. C. Turner (1968) showed that migrants first choose location over quality. “Bridgeheaders” want cheap rooms near jobs in the inner city. Later “consolidators” want ownership and space, and move to the periphery to build.
• A slum typically passes through these stages:
  1. Arrival and occupation: families rent rooms in old inner-city tenements, or squat on vacant public land, by overnight invasion or gradual accretion.
  2. Consolidation: huts of plastic and tin are rebuilt in brick. A rental market appears as early settlers let rooms to newcomers.
  3. Densification and vertical growth: upper floors are added, open spaces are built over and lanes narrow. Densities rise steeply.
  4. Recognition: the slum is notified or recognised, often before elections. Taps, toilets, lights and paved lanes follow.
  5. Upgrading, redevelopment or eviction: depending on land value and politics, the slum is improved in place, rebuilt as towers, or cleared.
• Slums on high-value central land face the strongest pressure for redevelopment. Those on hazardous or low-value land tend to persist without services.

Slums in Numbers

The World

• UN-Habitat put the world’s slum population at 1.12 billion in 2022, 24.8% of urban residents. This was 130 million more than in 2015.
• Over 85% live in three regions:
  • Eastern and South-Eastern Asia (362 million).
  • Central and Southern Asia (334 million).
  • Sub-Saharan Africa (265 million), where 53.6% of urban people live in slums, the highest share of any region.
• Brazil’s 2022 census counted 16.4 million people (8.1%) in 12,348 favelas and urban communities. Rocinha (72,021 people) is the largest.

India

• Census 2011:
  • 6.55 crore people in 1.39 crore households lived in slums in 2,613 towns, out of 4,041 statutory towns.
  • That was 17.4% of India’s urban population, 22.4% of the population of the slum-reporting towns and 5.4% of all Indians.
• States with the largest slum populations:
  • Maharashtra (1.18 crore) and undivided Andhra Pradesh (1.02 crore) together held a third.
  • West Bengal (64 lakh), Uttar Pradesh (62 lakh), Tamil Nadu (58 lakh) and Madhya Pradesh (57 lakh) followed.
  • Tamil Nadu had the most slum-reporting towns (507).
• Slum share of the urban population:
  • Highest: undivided Andhra Pradesh 36.1%, Chhattisgarh 32.0%, Madhya Pradesh 28.4%, Maharashtra 23.3%, Odisha 22.3% and West Bengal 22.1%.
  • Lowest: Keralam (Kerala) (1.3%), Goa (2.9%), Assam (4.5%) and Jharkhand (4.7%).
  • Manipur and three small UTs reported no slums.
• Cities: Greater Mumbai had 52 lakh slum dwellers, 41.8% of its corporation’s population. This is the largest number and among the highest shares of any Indian city.
  • Hyderabad, Kolkata, Delhi and Chennai each had roughly 15–25 lakh slum dwellers. Counts vary with the city boundary used.
  • 38% of slum households were in the 46 million-plus cities, and in 19 million-plus cities over a quarter of households lived in slums.
• Households:
  • 1.37 crore slum households, 17.4% of urban households.
  • Maharashtra 24.5 lakh, undivided Andhra Pradesh 24.2 lakh, Tamil Nadu 14.5 lakh and West Bengal 13.9 lakh. Those four and Madhya Pradesh held 64%.
  • Highest share of households: undivided Andhra Pradesh 35.7%, Chhattisgarh 31.9%, Madhya Pradesh 28.3%. Lowest: Keralam 1.5%.
• Trend:
  • Census 2001 gave the first detailed slum data: 5.24 crore people in 1,743 towns.
  • A government committee projected 10.4 crore by 2017, far above the census count.
  • UN-Habitat’s State of the World’s Cities 2010/11 credited India with lifting 5.97 crore people out of slum conditions.
• Amenities, Census 2011:

• Slums came close to the rest of the city on water and power, but lagged on toilets and drainage. Television and phones had spread faster than sanitation.
• Data gap: no slum count has been made since 2011. The next census, with enumeration referenced to 1 March 2027, will give the first update.

Factors Contributing to Slum Formation

• Rapid urbanisation and rural–urban migration:
  • Migrants arrive faster than cities can house them, so they settle near work in informal settlements.
  • Push: small holdings, agrarian distress, landlessness, caste oppression, floods and droughts.
  • Pull: jobs, wages, education and health care in the metropolis.
  • Migrants without savings or documents cannot enter the formal housing market.
• Housing shortage and lack of affordable housing:
  • India’s urban housing shortage was estimated at 18.78 million units (2012), 96% of it in the economically weaker and low-income groups.
  • High construction costs, private builders’ focus on the high-end market, and small, slow public housing leave the poor with little option but unauthorised land.
• High land prices and vertical growth:
  • Land is scarce in the centre. Prices rise with demand, speculation and low permitted floor space.
  • Vertical growth of offices and high-income towers pushes land values beyond the reach of the poor. Their only foothold is marginal land, or crowding into existing slums.
  • Market-led redevelopment with extra floor space can create “vertical slums” of poorly maintained rehabilitation towers.
• Land pressure from population growth and economic expansion:
  • IT-led and industrial growth in cities such as Bengaluru, Hyderabad and Pune has sharply raised demand for land.
  • As land grows scarce, informal housing spreads into peri-urban and interstitial spaces, often without basic services.
• Planning and governance failures:
  • Outdated master plans that ignore the poor and fail to reserve land for them.
  • Weak enforcement, institutional fragmentation and corruption.
• Urban poverty and inequality:
  • Informal, low-wage work and no social security mean even long-term residents cannot afford planned housing.
  • The slum is a survival strategy: cheap rent close to jobs.
• Natural increase within slums: high fertility, young age structures and limited access to education, health care and family planning add to growth and densification.
• Political economy:
  • Slums are vote banks. Regularisation before elections encourages more encroachment.
  • Real-estate interests, disputes over land ownership and fears of displacement delay redevelopment.
• Industrial location: factories, ports and construction sites attract labour without providing housing. Slums grew in the industrial States and mining towns of the Deccan and central India.
• Lack of balanced regional development: stagnant rural regions keep sending surplus labour to a few metros.

Associated Problems of Slums

Health

• Communicable diseases thrive with poor sanitation, open drains and contaminated water: cholera, typhoid, diarrhoea, hepatitis, tuberculosis, malaria and dengue.
• Overcrowding speeds the spread of respiratory infections.
• Malnutrition and higher infant and maternal mortality follow from poor diets and limited health care.
• Pandemics: COVID-19 (2020) showed the risk of density plus shared facilities.
  • Social distancing and handwashing are hard where one toilet seat serves dozens of people. A 2014 study of Mumbai’s slums found about one seat per 81 persons.
  • Dharavi contained its first wave through intensive tracing, testing and isolation, using community health workers and local leaders.
  • The lockdown destroyed informal livelihoods and triggered mass reverse migration.

Environment

• Encroachment on fragile land: riverbanks, wetlands, floodplains, mangroves, hill slopes and forest edges.
• Pollution:
  • Untreated sewage and solid waste pollute drains, rivers and groundwater.
  • Slums along the Yamuna in Delhi, the Mithi in Mumbai and the Cooum in Chennai both suffer from and add to river pollution.
• Indoor air pollution from biomass and kerosene cooking. Dependence on firewood also adds to deforestation. Exposure to toxic emissions where slums adjoin industry or dumpsites.
• Fire and hazard risk from crowded, flammable structures.

Basic Amenities and Infrastructure

• Chronic shortages of water, sanitation, electricity, paved lanes, drainage and transport.
• Overloaded networks and frequent breakdowns.
• Unsafe structures of temporary materials, vulnerable to fires, floods and collapse.

Economic

• Informal, insecure work with low wages and no social security.
• No access to formal credit or insurance, so dependence on moneylenders and debt traps.
• Evictions destroy homes, businesses and the links between home and work.
• Limited skills and education restrict mobility.

Social

• Stigma and exclusion in housing, jobs and services.
• Crime, substance abuse, domestic violence and juvenile delinquency. These are linked to poverty and overcrowding, not to slum dwellers as such.
• Vulnerability of women and children: trafficking, child labour, abuse, and lack of safe toilets.
• Stress and poor mental health from insecurity.

Legal and Governance

• Insecure tenure brings exploitation by land mafias and speculators, and the threat of eviction.
• Lack of formal recognition cuts residents off from services and welfare.
  • Identified and non-notified slums often get no municipal services at all.
• Weak enforcement and corruption allow slums to expand.

Location-Based Risk

• Flood-prone and landslide-prone sites:
  • Mumbai’s hill-slope slums have repeated landslides in the monsoon.
  • Chennai’s riverbank slums flooded in 2015.
• Heat stress under tin roofs.
• Climate change concentrates disaster losses on the urban poor.

Are Slums an Urban Menace?

• The case for “menace”:
  • Disease, pollution and crime.
  • Encroachment on public land and on flood channels.
  • Strain on services, and an unsightly city image.
• The case against:
  • Slums are the city’s affordable housing and its labour reserve. They house the workers that formal housing ignores.
  • They are economic hubs, as Dharavi’s workshops show.
  • Slums of hope are stepping stones for migrants.
  • The “menace” is a failure of land, housing and planning policy, not of slum dwellers.
• Most researchers and UN-Habitat now favour upgrading and inclusion over clearance.

Government Initiatives for Slums in India

Phases of Policy

• Clearance and relocation (1950s–1960s):
  • The Slum Areas (Improvement and Clearance) Act, 1956 gave the legal basis to identify, notify, improve or clear slums, first in the Union Territories.
  • Relocation to the periphery often moved poverty without ending it.
• Improvement in place (1970s–1990s):
  • State Slum Acts: the Maharashtra Slum Areas Act of 1971 allowed slums to be declared, improved and redeveloped.
  • Environmental Improvement of Urban Slums (1972): taps, drains, street lights and toilets.
  • Urban Basic Services for the Poor (1990): community-based services for slum dwellers.
  • The National Slum Development Programme (1996) gave central assistance to States in proportion to their slum population.
• Rehabilitation with the market (1990s–2000s):
  • Mumbai’s Slum Rehabilitation Scheme (1995) under the Slum Rehabilitation Authority.
    • Eligible families get free flats in situ. Developers are paid in extra floor space (FSI) and transferable development rights (TDR).
  • Valmiki Ambedkar Awas Yojana (2001): shelter, with community toilets under its Nirmal Bharat Abhiyan component.
  • Interest Subsidy Scheme for Housing the Urban Poor: interest subsidies for economically weaker sections.
• Mission era (since 2005):
  • JNNURM (2005):
    • Basic Services to the Urban Poor (BSUP) in the mission cities.
    • The Integrated Housing and Slum Development Programme (IHSDP) in smaller towns, which merged the earlier NSDP and VAMBAY.
  • Rajiv Awas Yojana (2011): “slum-free cities” through slum mapping, property rights and in-situ redevelopment. Its implementation phase was approved in 2013, and it was subsumed in 2015.
  • PMAY-Urban (2015): “Housing for All” through four verticals.
    • The verticals were in-situ slum redevelopment, credit-linked subsidy, affordable housing in partnership and beneficiary-led construction.
    • 1.22 crore houses had been sanctioned by December 2025.
    • Affordable Rental Housing Complexes (2020) for migrants were added after COVID-19.
  • PMAY-U 2.0 (2024): 1 crore more houses over five years with ₹2.30 lakh crore of central assistance.
    • Its four verticals are beneficiary-led construction, affordable housing in partnership, affordable rental housing and an interest subsidy.
    • There is no separate slum vertical. Landless beneficiaries can be given land rights (pattas).
• Supporting missions:
  • AMRUT 2.0 (2021): universal water taps and sewer or septage coverage.
  • SBM-Urban 2.0 (2021): toilets, waste management and used water.
  • Smart Cities Mission (2015–2025): services, housing and governance that reach slums indirectly.
  • HRIDAY (2015): heritage conservation with better living conditions in old inner-city quarters, which often include slum pockets.
  • DAY-NULM (2014): livelihoods and shelters for the urban homeless.
  • PM SVANidhi (2020): loans to street vendors.
  • National Urban Health Mission (2013).
• State tenure reforms: the Odisha Land Rights to Slum Dwellers Act, 2017 and its Jaga Mission gave land-right certificates and upgraded slums with drone-based mapping.

Redevelopment in the Megacities

• Common lessons: in-situ schemes keep jobs and networks; peripheral resettlement estates (Perumbakkam, Savda Ghevra) cut people off from work and services.

Challenges in Implementation and Redevelopment

• Demand side:
  • Affordability: the poorest cannot pay even subsidised prices or EMIs.
  • Access to finance: no income proof, credit history or collateral.
• Supply side:
  • Land scarcity: UN-Habitat projected India’s urban population at 600–675 million by 2030–35, about 675 million by 2035. A later UN estimate gives about 568 million by 2030. Stringent land-use controls, fragmented ownership and opaque land records add to the scarcity.
  • Rising construction costs: reported to be up by nearly 80% over the past decade, which makes affordable projects less viable.
  • Regulatory delays: many clearances from local bodies, State departments and environmental authorities.
  • Tenure disputes over encroached, railway, port or defence land.
  • Litigation and political resistance, and disputes over eligibility cut-off dates, so many residents are excluded.
  • Location: housing far from jobs leaves units vacant. Relocated families lose their livelihoods.
  • Quality and maintenance: rehabilitation towers with poor light, ventilation and upkeep.
  • Misuse: illegal subletting or sale of allotted units, and the re-emergence of slums.
  • Overburdened infrastructure when densities rise without matching services.
• Programme delivery:
  • Delays in execution and weak coordination between agencies.
  • Financial constraints and dependence on private developers.
  • Limited coverage, with a focus on select cities.
  • Little community participation in planning and execution.

Suggestions for Improvement

• Upgrade in situ wherever the site is safe. Relocate only from hazardous sites, nearby and with livelihoods planned.
• Fit the model to the place: local demographic, social and spatial conditions should shape each scheme, not a uniform template.
• Secure tenure first: land rights or long leases, as in Odisha. Families then invest in their own homes.
• Supply land and housing ahead of demand:
  • Sites and services schemes and inclusionary zoning.
  • Rental housing for migrants.
  • Reserving land for the economically weaker sections in master plans.
• Community participation and partnership: Ahmedabad’s slum networking and the community toilets built in Pune and Mumbai by NGOs with slum women’s groups.
• Decentralised services: community-managed toilets, small sewage and waste plants, and solar power.
• Finance: flexible subsidies, microfinance and self-help group credit, and cross-subsidy from land value capture.
• Curb misuse: post-allotment monitoring and firm oversight to stop illegal subletting and transfer of flats.
• Livelihoods and skills: mixed-use rehabilitation that keeps workshops and shops.
• Data: GIS and drone mapping of every slum, and a census update.
• Prevent new slums: balanced regional development, growth of small towns, and rural employment.

Case Studies

India

• Dharavi Redevelopment Project, Mumbai:
  • Dharavi is a notified area of about 254 ha, built on filled-in marshland between railway lines and Mahim Creek. It is one of Asia’s largest slums. Long called Asia’s largest, it is now often placed behind Orangi in Karachi.
  • The project was awarded in 2023 to a special purpose vehicle: Adani group 80%, Maharashtra 20% through the Slum Rehabilitation Authority. As a public–private partnership, it cross-subsidises rehabilitation housing through commercial development.
  • A master plan was approved in 2025, and the first construction permission issued in January 2025. Over 1.13 lakh structures were numbered in the eligibility survey.
  • Rehabilitation towers (10,432 flats of 350 sq ft) began on railway land at Matunga in 2026. Completion is targeted for 2032.
  • Issues:
    • Eligibility of upper-floor and post-cut-off residents, and relocation of the ineligible to distant sites.
    • Survival of Dharavi’s informal industries.
    • Land transfers and litigation.
• Mumbai Slum Rehabilitation Scheme (1995):
  • Free in-situ flats paid for by extra floor space and TDR to developers.
  • It produced large numbers of units, but also vertical slums, poor construction, exclusion errors and loss of workshops.
• Ahmedabad Slum Networking Programme (mid-1990s):
  • In-situ upgrading with water, sewerage, drainage, paved lanes, lights and waste collection.
  • A partnership of the municipal corporation, NGOs and residents with cost sharing.
  • Results: better health and school attendance, and greater security of tenure.
• Odisha’s Jaga Mission: land-rights certificates under the 2017 Act, and drone-mapped upgrading of slums in many towns. Bhubaneswar was known early for such certificates, which cut the risk of eviction. Tenure security is the base for investment.
• Indore: in-situ redevelopment under PMAY-U with strong municipal leadership, minimal displacement, GIS-based slum mapping and integrated water, sanitation and waste services.
• Delhi’s resettlement colonies (Bawana, Narela, Savda Ghevra): legal plots, but distance from work, long commutes and weak services.
• Pune and Mumbai community toilets: designed and run by NGOs with women’s savings groups, which improved maintenance and use.
• Rajiv Awas Yojana pilots in several cities, including Jaipur and Patna: mapping and tenure, limited by funds and implementation.

Abroad

• Kibera, Nairobi:
  • About 256 ha. The 2019 census counted 185,777 people in Kibra, far below the older claims of 0.6–1 million.
  • Most residents are tenants of structure owners on government land.
  • The Kenya Slum Upgrading Programme with UN-Habitat (2004) moved Soweto East residents to decanting sites and new flats.
• Rocinha and the favelas, Rio de Janeiro:
  • Consolidated hillside favelas.
  • Upgrading under Favela-Bairro (1994) and federal PAC works (2007), with debates over titling and policing.
• Orangi Pilot Project, Karachi (1980):
  • Founded by Akhtar Hameed Khan.
  • Residents built and paid for their own lane sewers, with technical help. It became a model of low-cost, community-led sanitation.

• The lesson of the cases: success came with tenure, participation, services and livelihoods kept together. Clearance or towers alone recreated slums elsewhere.