How Human Activities Are Drowning Our Water

Water, an omnipresent resource, covers more than 70 percent of the Earth’s surface. But despite its abundance, freshwater—suitable for human consumption and ecosystems—remains a scarce commodity, comprising only 2.5 percent of the global water supply. Of this fraction, much is locked away in polar ice caps or buried deep within aquifers, making less than one percent of the world’s water accessible for daily use. The question of water availability, however, goes beyond simple arithmetic. The real crisis stems from how human activities have altered the quality and availability of this vital resource.

Alejandra Fonseca Salazar, an expert in sustainable campus management at the University Coordination for Sustainability (UNAM), emphasizes the critical role human action plays in water contamination and scarcity. From industrial discharges and domestic waste mismanagement to pesticide use and deforestation, human enterprises are responsible for degrading water quality. Such degradation is particularly troubling in urban contexts, where millions of people depend on reliable water supplies for both consumption and economic activities.

This is the setting for an important discussion on Territorial Transformations and Hydro-Climatic Crises, a seminar organized by the University Program of Studies on the City at UNAM. During the event, Fonseca Salazar provided a sobering overview of the challenges associated with urban water management, highlighting how cities like Mexico City—where approximately 63 percent of the water comes from underground aquifers—are already facing serious consequences of mismanagement.

A Sobering Statistical Snapshot

Globally, water scarcity paints a grim picture. According to the United Nations World Water Development Report 2023, 2 billion people—about 26 percent of the world's population—do not have access to safely managed drinking water services. Furthermore, 46 percent lack access to proper sanitation, and nearly 2.3 billion individuals do not have basic handwashing facilities, a crucial issue in the face of public health crises like the COVID-19 pandemic.

These statistics shed light on a complex problem: it’s not just about having water; it’s about having clean water. As Fonseca Salazar notes, the quality of available water is deeply compromised, exacerbated by factors like climate change, aging infrastructure, and pollution from industrial and agricultural sources.

In Mexico, 61 percent of water is sourced from surface bodies like rivers and lakes, while 39 percent comes from underground. Disturbingly, a 2022 report by Mexico's National Water Quality Measurement Network found that nearly 60 percent of the country’s monitored water bodies were contaminated. High levels of naturally occurring but harmful substances like arsenic and fluoride were found in several regions, leading to public health concerns.

Climate change plays a substantial role in aggravating water issues. Fonseca Salazar explains how extreme weather events—such as intense rainfall or prolonged droughts—disrupt natural water cycles, further complicating urban water management. Floods can concentrate pollutants in water sources, while droughts lead to higher concentrations of minerals and toxins, making water treatment processes more challenging and costly.

Urban areas, particularly sprawling metropolises like Mexico City, are vulnerable to these climate-driven extremes. Relying heavily on aquifers for nearly two-thirds of its water supply, the city also faces the additional challenge of significant water loss—around 40 percent—due to leaky infrastructure. Such figures highlight a structural problem in delivering water efficiently, calling for urgent modernization of water distribution systems.

Innovation in the Face of Crisis

Amid the sobering statistics, there is hope in innovative approaches to urban water management. Fonseca Salazar underscores the importance of improving water quality and addressing infrastructure inefficiencies by adopting several key strategies.

First, rainwater harvesting presents a potential boon for water-scarce cities. Mexico City, for instance, experiences heavy rains during certain seasons, yet much of this precious resource is lost. Properly designed systems for collecting and utilizing rainwater could provide significant relief to overburdened water supply networks. In areas where aquifers are being over-exploited, capturing rainwater could help alleviate stress on these underground reserves.

Another critical solution lies in wastewater treatment. Currently, only 15 percent of wastewater in Mexico City is adequately treated. Expanding wastewater treatment infrastructure could not only increase water availability but also enhance water quality for both domestic and industrial uses. By reclaiming water from waste, cities can create a more sustainable loop of water reuse, reducing the need for fresh extraction from fragile ecosystems.

Fonseca Salazar also highlights smaller-scale initiatives, many of which are taking root across Mexico and other parts of the world. At the UNAM campus, for example, a treatment plant at the Acatlán School of Higher Studies and an artificial wetland at the School of Chemistry showcase the potential of local water management solutions. These smaller, community-driven projects demonstrate that while large-scale infrastructure modernization is vital, localized interventions can also play a significant role in mitigating the water crisis.

A New Water Ethic

The issue of water management has reached international significance. The United Nations Sustainable Development Goals (SDGs) include a dedicated target for water (SDG 6), which seeks to ensure the availability and sustainable management of water and sanitation for all by 2030. Improving water quality is a major component of this objective, alongside efforts to reduce pollution, eliminate dumping, and minimize the release of hazardous chemicals.

But these goals, while ambitious, require actionable plans. In Mexico, as in many other countries, achieving sustainable water management will necessitate investments in infrastructure, stricter regulation of pollutants, and a cultural shift toward more responsible water use. Crucially, it will also require a focus on equity—ensuring that marginalized communities, which often bear the brunt of water scarcity and contamination, have reliable access to clean water.

At the heart of the water crisis is a broader issue: the human relationship with nature and natural resources. Fonseca Salazar’s call to modernize infrastructure and promote sustainable water use reflects a deeper need to rethink how societies value water. Beyond being a mere commodity or utility, water is the lifeblood of ecosystems and communities alike. Its management must be guided not only by economic or technological imperatives but by a holistic understanding of water as a shared and finite resource.

In this context, the future of water management in cities may well depend on cultivating a new water ethic—one that prioritizes conservation, sustainability, and resilience in the face of climatic and environmental changes. For cities like Mexico City, this ethic could involve a combination of top-down reforms and grassroots innovations. Whether through rainwater harvesting, community-led treatment plants, or the revamping of national water policies, the path forward must be multifaceted and inclusive.

The road to solving the global water crisis is long, and challenges are abundant. But with concerted efforts, the tide can turn in favor of cleaner, more sustainable, and equitable water systems—ensuring that the precious one percent of Earth’s freshwater is safeguarded for generations to come.