Between Patterns and Flows: The invisible boundary of smart cities passes through water governance.

From the origins of cities to innovation agendas, water remains a structuring axis of urban life, revealing that there is no intelligence or resilience without equitable management.

*By Marcelo Nery

No city emerges, expands, or consolidates without a water supply capable of ensuring the survival of its population and the reproduction of its urban dynamics. More than a resource intended for human consumption, water constitutes a structuring element of urban space and the material foundation of collective life.

Historically, cities were established along rivers. The proximity of water enabled economic production, transportation, and territorial integration, while also providing energy and sustaining the daily organization of social life. With the consolidation of modern metropolises, this centrality did not diminish; on the contrary, it was expanded and reorganized through large-scale works and networks: water began to support industrial processes, production chains, and increasingly complex urban infrastructure structures.

In the 20th century, the expansion of water supply and sewage systems was celebrated as a civilizational achievement and a landmark of modernity. The universalization of sanitation became an indicator of public health and urban progress. However, this indicator reveals its political dimension; since, far from being restricted to the provision of an essential resource, water has become an instrument of territorial management and a persistent marker of social inequalities.

South Africa offers a prime example. During the apartheid regime, water supply was systematically prioritized in areas designated for socially and politically dominant groups, while territories occupied by marginalized populations faced precariousness and scarcity. Even after the constitutional recognition of the right to water, the spatial legacy of this unequal order remains visible. The 2018 water crisis in Cape Town highlighted how, in contexts of scarcity, pre-existing social hierarchies tend to deepen: more privileged neighborhoods mobilize private resources for adaptation, while more vulnerable segments of the population remain dependent on fragile public services—a predictable, albeit deeply regrettable, scenario.

A similar dynamic can be observed in the city of São Paulo. As demonstrated in a study on urban-demographic patterns, “even with the near universalization of basic sanitation services (...), the sanitary conditions of the city of São Paulo still constitute an important element of intra-urban inequality” (Nery et al., 2019, p. 30). The widespread dissemination of these services, therefore, does not in itself eliminate the asymmetries inscribed in the territory; on the contrary, it can coexist with historical processes of socio-spatial differentiation, expressed in the conditions of access and the quality of their distribution.

In the cited study, access to potable water—as well as to sewage systems and garbage collection—does not appear as the main marker of local differences. Variables associated with urban expansion and the socioeconomic characteristics of the head of household, for example, have a greater weight in distinguishing between localities. Even so, these three essential urban services are part of the structure that differentiates territories. Even when they are not the most evident factors, they structure opportunities, produce vulnerabilities, and condition development trajectories.

The importance of water goes beyond the strictly sanitary dimension. It integrates a socio-environmental system that articulates "geoecological elements with the social order" (Ibid., p. 13), synthesizing how environmental characteristics—such as areas of geological risk, water sources, and peri-urban zones—intertwine with urbanization processes.

Water source protection areas exemplify this tension. A significant portion of São Paulo's territory is located in strategic zones for water supply. Urban expansion into these spaces highlights the conflict between the right to housing and environmental preservation, which, in certain situations, takes on even more worrying dimensions due to the actions of criminal organizations. Thus, water emerges as a permanent challenge for public policies and territorial management.

This logic is also evident in the Civil Defense alert system. Floods and landslides disproportionately affect areas where infrastructure is weaker and urban development has occurred outside the formal planning guidelines. Vulnerability, in this case, does not stem exclusively from natural factors, but from the interaction between the environment and society.

Climate change intensifies this scenario. Extreme water scarcity and precipitation events challenge supply systems and disaster risk management. Cities with integrated planning and constant monitoring tend to cope better with water crises, while those marked by inequality and territorial fragmentation see their vulnerabilities amplified. In this sense, water governance becomes a key indicator of urban resilience.

These challenges produce impacts that go beyond the environmental dimension. Prolonged disruptions compromise production chains and affect the city's economic vitality. Larger rainfall events also reconfigure the urban experience and alter citizens' relationship with the space they inhabit. In both cases, the channeling of waterways and the waterproofing of the soil have sought to domesticate nature in the name of urban progress. However, recurring floods remind us that water does not disappear under concrete nor does it fully submit to urban planning, imposing its own limits.

Technical control over water takes on a new dimension when we consider smart cities. In the water sector, efficiency is promised through sensors, real-time monitoring, and the expanded use of artificial intelligence. However, the incorporation of technology does not, in itself, guarantee resilience. Recent episodes of dealing with extreme weather events show that communication failures, institutional bottlenecks, and interoperability problems can compromise emergency responses. Their effectiveness depends on inter-institutional coordination, integrated communication, clarity in decision-making flows, and prior preparation. Warning systems, satellite imagery, drones, and digital models are fundamental tools, but they only produce results when integrated into cooperative networks. There is no smart city where water is not governed equitably.

Furthermore, a city can be digital and still reproduce inequalities in access to water, thus being hardly "smart." True urban intelligence—connected, efficient, and sustainable—requires integration between technology, planning, and inclusion. Sophisticated monitoring systems need to work in conjunction with reducing vulnerabilities concentrated in territories and groups that are more socially exposed.

São Paulo offers a concrete example of this need for integration between technique, planning, and inclusion. In territories where housing, environmental, sanitary, mobility, and security dimensions intertwine, water resources continue to reveal persistent inequalities. Exposure to risk and environmental fragility profoundly differentiate these territories from consolidated neighborhoods. Thus, even today, water remains an active element in the (re)production of the social structure.

Returning to the South African case, we observe how water can solidify historical hierarchies, while the case of São Paulo demonstrates that it continues to structure urban inequalities and vulnerabilities. These findings call into question interpretations of smart city projects that assume that technological integration can operate in a self-sufficient manner in producing urban resilience.

Ultimately, water has been, is, and will continue to be a fundamental condition of citizenship. Where it flows safely and equitably, the city can prosper inclusively; where it is scarce or unequally distributed, its fissures become visible. To think about water is to think about the city—not only as a physical space, but as a complex system in which environment and society are inseparable. True urban intelligence will be that which recognizes that water, more than a resource, is the foundation of equity and sustainability. If water management remains fragile or unequal, this is not a sectoral failure, but a limitation of the project that aims to be intelligent.

¹The 2018 water crisis in Cape Town, South Africa, was triggered by a severe drought over the previous three years, which brought the city's reservoirs to critical levels. Faced with the possibility of a so-called "Day Zero"—when public water supply could be interrupted—the government imposed strict consumption restrictions. The crisis was averted by a drastic reduction in water use and the return of rainfall, but it highlighted weaknesses in water planning and profound socio-spatial inequalities in access to essential public resources and in the capacity for adaptation.

²NERY, Marcelo Batista; SOUZA, Altay Alves Lino de; ADORNO, Sergio. The urban-demographic patterns of the capital of São Paulo. Estudos Avançados, São Paulo, v. 33, n. 97, p. 5–36, 2019. DOI: https://doi.org/10.1590/s0103-4014.2019.3397.002.