Pakistan’s water crisis is often framed in terms of scarcity, but contamination reveals a deeper truth.
Water security without water safety is an illusion.
Mohammad Ehsan Leghari
In Pakistan, water is not simply a natural resource; it is the thread that binds ecology, economy, and society. Rivers have shaped settlements, agriculture defines livelihoods, and access to water determines health and dignity. Yet beneath this visible dependence lies a crisis that remains largely unspoken. While national debates focus on water scarcity on dams, canals, and river flows; a slower and more dangerous emergency continues to unfold underground. Groundwater contamination, largely invisible, poorly monitored, and weakly governed, has become one of Pakistan’s most serious environmental and public-health challenges.
This crisis matters because groundwater is no longer a supplementary source. Over the last few decades, it has become the backbone of Pakistan’s water system. More than sixty per cent of the population relies on groundwater for drinking, while agriculture; particularly in Punjab depends overwhelmingly on groundwater abstraction to sustain crops during periods of unreliable canal supplies. This is true for parts of Sindh also (PCRWR, 2018; World Bank, 2019). When this hidden resource becomes unsafe, the consequences extend far beyond environmental degradation; they threaten food security, public health, and social stability.
Yet Pakistan’s groundwater contamination problem is often misunderstood because it is treated as a single, uniform phenomenon. In reality, groundwater behaves differently across regions, shaped by geology, hydrology, land use, and urban form. Karachi, Hyderabad, and the agricultural heartlands of Punjab face groundwater crises that are fundamentally different in origin and nature. Recognizing these differences is essential if responses are to be effective rather than symbolic.
Karachi, Pakistan’s largest city, takes almost 85 percent of water from Indus through Keenjhar Lake, illustrates how geological limits and human interventions can combine to undermine groundwater safety. Unlike many inland cities, Karachi was never endowed with extensive freshwater aquifers suitable for large-scale drinking water supply. Its coastal geology and proximity to the Arabian Sea mean that much of the subsurface water is naturally saline or brackish. Scientific assessments and planning studies have long documented seawater intrusion into coastal aquifers around Karachi, rendering groundwater unsuitable for drinking without desalination or advanced treatment (Kazmi, 2015; JICA, 2020). PCRWR monitoring has repeatedly identified high salinity and bacteriological contamination in water samples collected across the city (PCRWR, 2017).
This natural limitation has been compounded by decades of unplanned urbanization and infrastructure neglect. Karachi’s sewerage system has failed to keep pace with population growth, resulting in widespread leakage of untreated sewage into shallow subsurface layers. Industrial effluents, often discharged without adequate treatment, further degrade groundwater quality with heavy metals and organic pollutants (WHO, 2017). In this context, reliance on groundwater for drinking is not a solution to Karachi’s water crisis; it is a public-health risk.
Karachi’s groundwater stress is further intensified by long-standing, largely unregulated sand and gravel (reti and bajri) extraction from the beds of its two seasonal rivers, the Lyari and the Malir. For decades, these riverbeds have supplied construction material for the expanding metropolis. Environmental assessments and academic studies show that sustained riverbed mining has physically removed alluvial sediments that once acted as shallow aquifers and natural water-storage zones, reducing the capacity of floodplain deposits to retain and slowly recharge freshwater (Kazmi, 2015; PCRWR, 2017; Sadaf, 2023). Channel incision, loss of riparian soils, and disruption of hydraulic connectivity between river flows and adjacent aquifers have been widely reported along both rivers (Dawn, 2022; JICA, 2020).
Hydro-geochemical studies along the Malir and Lyari corridors indicate that where sand mining has been intense, shallow wells exhibit very high total dissolved solids and bacteriological contamination—reflecting disrupted recharge processes, exposed sediments, and increased mixing of polluted surface water and saline groundwater (Sadaf, 2023; PCRWR, 2017). In effect, the removal of riverbed sediments has “dug out” what limited local freshwater storage once existed, creating new localized hotspots of salinity and contamination. This degradation must be understood as a distinct but compounding factor alongside Karachi’s broader coastal seawater intrusion problem.
Read: Groundwater Contamination: Understanding the Threat
Hyderabad and other inland cities of Sindh face a different groundwater reality. Located on the Indus alluvial plain, Hyderabad and adjacent districts draw water from aquifers formed by relatively young river sediments. These sediments are chemically reactive and, under certain geochemical conditions, release naturally occurring arsenic into groundwater. Extensive research across the Indus Basin has shown that arsenic mobilization is linked to sediment composition, redox conditions, and groundwater–surface water interactions (Podgorski et al., 2017). In different parts of Sindh, multiple studies have documented arsenic concentrations far exceeding World Health Organization guideline values, exposing large populations to chronic health risks (Brahman et al., 2013; PCRWR, 2018).
What makes arsenic contamination particularly dangerous is its invisibility. Arsenic-laden water is typically colourless, tasteless, and odourless. Households may consume such water for years before health effects become apparent. In many towns, this geogenic contamination is further aggravated by sewage infiltration and agricultural runoff, which introduce nitrates, pathogens, and other pollutants into shallow aquifers where sanitation infrastructure is weak.
Punjab’s groundwater challenge adds yet another dimension. In much of central and parts of southern Punjab, groundwater remains physically accessible and has long been perceived as a reliable buffer against canal shortages. However, this apparent abundance masks a steady deterioration in quality. Intensive agriculture, characterized by heavy fertilizer and pesticide use, has resulted in nitrate contamination in many aquifers, particularly in intensively farmed districts (Azizullah et al., 2011). Industrial clusters, such as tanneries in Kasur and manufacturing hubs in Faisalabad and Sialkot, have introduced chromium, lead, and other heavy metals into local groundwater systems (PCRWR, 2019). Once introduced, these pollutants persist for decades, slowly migrating through aquifers and expanding exposure zones.
The human cost of this silent contamination is immense. Chronic arsenic exposure is associated with skin lesions, cardiovascular disease, diabetes, and multiple forms of cancer (Smith et al., 2000). Elevated nitrate levels are linked to infant methemoglobinemia, commonly known as “blue baby syndrome” (WHO, 2017). Bacteriological contamination continues to drive outbreaks of diarrhoeal disease, typhoid, and hepatitis, which remain among the leading causes of child mortality in Pakistan (UNICEF, 2021). These impacts fall disproportionately on rural communities and urban informal settlements, where households lack access to alternative water sources, filtration systems, or adequate healthcare.
Despite mounting evidence, institutional responses remain fragmented. The Pakistan Council of Research in Water Resources has repeatedly highlighted unsafe groundwater quality through national monitoring and arsenic surveys, yet routine quality testing is still absent in many public water supply schemes (PCRWR, 2018). Universities and research institutions have produced robust contamination maps and hydrogeological analyses, but these findings are rarely translated into enforceable regulation. Groundwater governance remains dispersed across water supply agencies, environmental protection departments, irrigation authorities, and health institutions, with no single entity responsible for safeguarding groundwater quality.
Addressing groundwater contamination therefore requires a fundamental shift in how water security is understood. Quantity alone is not enough. Coastal cities like Karachi must acknowledge geological limits, curb riverbed mining, strictly control urban and industrial pollution, and priorities surface water and desalination where appropriate. Inland cities require systematic arsenic testing, targeted treatment technologies, and protection of recharge zones from sewage and agrochemical contamination. In Punjab, and also canal irrigation areas of Sindh, reducing chemical overuse and enforcing industrial effluent standards are essential to prevent further degradation of aquifers.
Pakistan’s water crisis is often framed in terms of scarcity, but contamination reveals a deeper truth. Water security without water safety is an illusion. Aquifers once polluted cannot be easily restored, and the costs of inaction will be borne not by abstract future generations, but by children already drinking unsafe water today. Clean groundwater is not a luxury, nor a regional privilege. It is a basic right—and a national responsibility.
References
Azizullah, A., Khattak, M.N.K., Richter, P. and Häder, D.P. (2011) ‘Water pollution in Pakistan and its impact on public health: A review’, Environment International, 37(2), pp. 479–497.
Brahman, K.D., Kazi, T.G., Afridi, H.I., Naseem, S. and Arain, S.S. (2013) ‘Evaluation of arsenic exposure to population of Hyderabad, Pakistan, through drinking water’, Journal of Hazardous Materials, 262, pp. 152–158.
Dawn (2022) ‘Wasteland foretold: Sand mining in Malir and its environmental impacts’, Dawn, 22 March.
JICA (2020) The Project for Karachi Water Supply and Sewerage Improvement. Japan International Cooperation Agency.
Kazmi, S.S.A. (2015) Geology and Hydrogeology of the Karachi Region. Karachi: University of Karachi Press.
PCRWR (2017) National Water Quality Monitoring Programme Report: Karachi Region. Islamabad: Pakistan Council of Research in Water Resources.
PCRWR (2018) National Arsenic Monitoring Survey. Islamabad: Pakistan Council of Research in Water Resources.
PCRWR (2019) Water Quality Status of Pakistan. Islamabad: Pakistan Council of Research in Water Resources.
Podgorski, J., Eqani, S.A.M.A.S., Khanam, T., Ullah, R., Shen, H. and Berg, M. (2017) ‘Extensive arsenic contamination in high-pH groundwater of the Indus Valley’, Science Advances, 3(8), e1700935.
Sadaf, R. (2023) ‘Hydro-geochemical characterisation of groundwater in alluvial plains of Lyari and Malir rivers, Karachi’, Pakistan Journal of Scientific and Industrial Research Series A: Physical Sciences.
Smith, A.H., Lingas, E.O. and Rahman, M. (2000) ‘Contamination of drinking-water by arsenic: A public health emergency’, Bulletin of the World Health Organization, 78(9), pp. 1093–1103.
UNICEF (2021) Water, Sanitation and Hygiene in Pakistan: Key Challenges. Islamabad: UNICEF Pakistan.
WHO (2017) Guidelines for Drinking-Water Quality, 4th edn. Geneva: World Health Organization.
World Bank (2019) Pakistan: Getting More from Water. Washington, DC: World Bank.
Read: When water runs out, women suffer more
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Mohammad Ehsan Leghari is a water expert, former Member (Sindh), Indus River System Authority (IRSA), and former Managing Director, SIDA.
