Urban Water and Sanitation Challenges: Ensuring Safe Access

Every day, billions of people in cities around the world turn on a tap and expect clean water to flow. But for a staggering number of urban residents – especially those living in informal settlements – that basic expectation is far from guaranteed. As of 2024, approximately 2.1 billion people globally still lack access to safely managed drinking water, and 3.4 billion lack safely managed sanitation services. Urban areas, despite being centres of economic growth and infrastructure, are increasingly struggling to keep pace with the demand for safe water and adequate sanitation. The consequences are severe: disease outbreaks, environmental degradation, and deepening cycles of poverty.

The growing pressure on urban water supply 🔗

Cities are expanding at an unprecedented rate, and their water infrastructure is buckling under the pressure. In Southeast Asia, for example, many urban water supply systems are increasingly strained by sprawling urbanisation, industrial demands, and economic growth. As urban populations swell, the demand for water – for drinking, cooking, sanitation, and industrial use – frequently exceeds what existing systems can deliver. Aging pipelines, insufficient treatment plants, and poor distribution networks compound the problem.

Urbanisation drives increased water demand in two key ways: the rise in urban population and the expansion of water usage per urban resident. This dual pressure means cities must not only serve more people but also meet higher per capita consumption levels driven by changing lifestyles and economic activity.

Groundwater depletion: a hidden crisis 🔗

When surface water sources are insufficient, cities often turn to groundwater. But this reliance comes at a cost. A comprehensive study published in Nature found that groundwater levels are declining in 71% of monitored aquifers worldwide, with depletion rates accelerating significantly since the year 2000. Urban centres are major contributors to this trend, as they pump out groundwater faster than natural processes can replenish it.

Research on China’s cities revealed that around 180 prefecture-level cities face at least one form of groundwater pressure – either depletion or quality contamination – affecting roughly 311 million urban residents. Of these, 40 cities face both quantity and quality problems simultaneously, creating acute risks to drinking water safety. The issue isn’t confined to China. India, with its massive groundwater consumption, is approaching what the United Nations University has identified as a critical environmental tipping point for groundwater depletion – one that some countries, like Saudi Arabia, have already crossed.

In cities where aquifers run dry, the consequences extend beyond water scarcity. Over-extraction of groundwater can cause land subsidence, permanent reduction in aquifer storage capacity, and in coastal areas, saltwater intrusion that contaminates freshwater supplies.

Pollution of urban water sources 🔗

Even where water is physically available, it may not be safe to drink. Industrial discharge, untreated sewage, agricultural runoff, and improper waste disposal contaminate both surface water and groundwater sources in urban areas. Pollution and inefficiencies in urban water use degrade water quality, often leaving communities with no choice but to draw on already stressed groundwater for their daily needs.

In Dhaka, Bangladesh, for instance, a significant portion of wastewater flows into drains and surface waters without treatment, leading to severe fecal contamination of urban water sources. This kind of contamination is not unique to Dhaka – it is a pattern seen in rapidly urbanising cities across South Asia, sub-Saharan Africa, and Latin America.

Sanitation in slum areas: a public health emergency 🔗

Rapid urbanisation in developing countries often outpaces the development of essential infrastructure, leading to the expansion of informal settlements where access to basic services like clean water is severely limited. In these slum settlements, sanitation conditions are often dire. Shared toilets serve dozens of families, open drains carry untreated waste through narrow alleyways, and open defecation remains common in many areas.

Globally, 354 million people still practise open defecation, while 555 million use unimproved sanitation facilities. The burden falls disproportionately on people living in low-income countries and informal urban settlements, where overcrowding makes sanitation challenges even more acute.

How overcrowding fuels contamination 🔗

In densely populated slum areas, the close proximity of water sources and sanitation facilities creates a dangerous setup. In Kenyan slum communities, studies have found that the congestion in urban slums does not allow adequate distance between wells and pit latrines, enabling microorganisms from fecal matter to migrate into underground water sources. This means that even when residents have access to a water point, the water itself may be heavily contaminated.

A WASH study conducted in Kolkata’s urban slums found that poor drainage led to waterlogging during monsoon months, along with fecal contamination of the piped water supply. The study also noted that about one in ten families disposed of children’s stool in open environments, amplifying the risk of fecal-oral disease transmission. Street food vendors operating without basic hygiene further compounded the risk of waterborne infection spread.

Women and girls bear a disproportionate burden 🔗

In most countries with available data, women and girls are primarily responsible for water collection, with many in sub-Saharan Africa and Central and Southern Asia spending more than 30 minutes per day on this task. Time spent fetching water from distant or unsafe sources reduces opportunities for education and employment. The lack of private, clean sanitation facilities also affects menstrual hygiene management, with significant implications for the health and dignity of adolescent girls.

Consequences of poor sanitation: the disease burden 🔗

Inadequate water and sanitation services are directly linked to a heavy burden of preventable disease. Contaminated water serves as a primary vehicle for the spread of diseases including cholera, diarrhoea, typhoid, and dysentery, with children under five facing the greatest risk.

Diarrhoea: a leading killer of children 🔗

Diarrhoeal disease remains one of the most devastating consequences of poor water and sanitation. According to UNICEF, diarrhoea claims the lives of approximately 1,300 children every day, predominantly in low-income urban areas. For malnourished children – common in slum communities due to widespread poverty – the risk is even higher. Weakened immune systems struggle to fight off infections, leading to more severe outcomes and long-term developmental impacts.

The economic toll is substantial too. When children fall sick, parents miss work to provide care, household finances are strained by medical costs, and children miss school – perpetuating cycles of poverty and inequality.

Cholera: thriving in neglected environments 🔗

Cholera, caused by the bacterium Vibrio cholerae, is closely associated with environments lacking safe water and proper sanitation. It causes severe watery diarrhoea that can lead to rapid dehydration and death if untreated. In 2024 alone, more than 560,000 cholera cases and 6,000 deaths were reported across 60 countries, underscoring the persisting inequalities in access to even basic WASH services.

Cholera outbreaks in slums across sub-Saharan Africa and South Asia have repeatedly highlighted the critical need for sanitation improvements in high-density urban environments. Without adequate drainage and waste treatment, the bacterium easily contaminates drinking water, sparking outbreaks that can spread rapidly through overcrowded communities.

Typhoid, hepatitis, and beyond 🔗

The threat extends well beyond cholera and diarrhoea. Inadequate personal and domestic hygiene has been linked to the spread of numerous infectious diseases, including typhoid, hepatitis, polio, cryptosporidiosis, and schistosomiasis. Typhoid fever, spread through contaminated food and water, is a major concern in overcrowded settlements where healthcare access is limited. Left untreated, it causes prolonged fever, weakness, and potentially fatal complications.

Climate change further compounds these risks, as rising temperatures can alter pathogen survival and replication, heavy rainfall events can overwhelm water and sanitation infrastructure, and droughts can concentrate pathogens in limited water supplies. The Intergovernmental Panel on Climate Change has stated with very high confidence that increased risks of food- and waterborne diseases can be expected if climate change continues on its current trajectory.

What needs to change? 🔗

Addressing urban water and sanitation challenges requires action on multiple fronts. While the total number of people lacking safely managed drinking water has declined globally, the number without access has actually increased in urban areas and in low-income countries. This means that current approaches are not keeping up with the pace of urbanisation.

Key priorities include expanding piped water networks and sewage treatment capacity in growing cities, protecting groundwater sources from over-extraction and contamination, and ensuring that informal settlements are integrated into urban planning rather than left unserved. Water demand management strategies – including tariff reforms, water loss reduction, and promotion of water-saving technologies – can help reduce consumption and ease pressure on both surface and groundwater sources.

At the community level, household-level water treatment, hygiene education, and improved waste disposal practices can make a significant difference. Research has shown that targeted public health interventions, including water chlorination and health education, can reduce the severity of waterborne disease outbreaks by as much as 35% over three years.

But ultimately, sustainable change requires political will and investment. The WHO/UNICEF Joint Monitoring Programme has warned that as we approach the final years of the Sustainable Development Goals period, the world is not on track to achieve universal coverage of basic WASH services by 2030, and universal coverage of safely managed services is increasingly out of reach.

The bottom line 🔗

Urban water and sanitation challenges are not abstract policy problems. They are daily realities for billions of people – realities that determine whether a child survives a bout of diarrhoea, whether a family can afford clean drinking water, and whether a girl can attend school with dignity. The infrastructure gaps, groundwater depletion, pollution, and sanitation failures discussed here are interconnected, and they demand integrated solutions that treat safe water and sanitation as non-negotiable rights, not optional services.

What do you think? With urban populations continuing to grow rapidly, what role should local communities play in managing their own water and sanitation systems? And how can cities balance economic development with the urgent need to protect shrinking groundwater reserves?

References

1. https://academic.oup.com/jid/article/224/Supplement_5/S573/6433799
2. https://data.unicef.org/topic/water-and-sanitation/sanitation/
3. https://www.who.int/news/item/26-08-2025-1-in-4-people-globally-still-lack-access-to-safe-drinking-water—who–unicef
4. https://www.sei.org/perspectives/improving-urban-water-use-groundwater-depletion/