PUMAGUA. Safe Water in University City

The water crisis has become one of the most pressing challenges of the 21^st century. Urban growth, overexploitation of aquifers, and pollution have put a strain on water availability in multiple regions of the world (Madani, 2026). Faced with this scenario, higher education institutions not only generate knowledge to understand the problem but can also become spaces for concrete action.

Because of their scale and complexity, university campuses operate like small cities: they gather thousands of people, diverse infrastructure, and a constant demand for basic services, including water supply (Alshuwaikhat & Abubakar, 2008). Managing this resource within a university involves technical, organizational, and cultural challenges that require comprehensive solutions (Boiocchi et al., 2025).

Geophone leak detection

 Eduardo Hernández

Several institutions in Mexico develop different initiatives for water management. The Panamerican University, for example, has a project for the improvement of operating systems (https://www.up.edu.mx/en/noticias/investigacion/transforming-water-management-in-mexico/), while Monterrey Institute of Technology seeks to consolidate itself as a model of sustainability with their Ruta Azul (Blue Route) project (https://tec.mx/es/florecimiento-humano/desarrollo-sostenible/ruta-azul).​ At UNAM, the Water Management, Use, and Reuse Program (PUMAGUA) has been going on for 17 years, working to strengthen sustainable water management in our University City (CU) and to extend this effort to our external campuses.

PUMAGUA REPRESENTS AN INSTITUTIONAL STRATEGY THAT ARTICULATES MEASUREMENT, INFRASTRUCTURE, REGULATIONS, AND ENVIRONMENTAL CULTURE

More than an operational scheme, PUMAGUA represents an institutional strategy that articulates measurement, infrastructure, regulations, and environmental culture. Its experience shows that campuses can function as living laboratories of sustainability, capable of transforming the way water is managed and generating learning that can be replicated in other institutions.

THE WATER ROUTE ON CAMPUS
UNAM Central Campus (as a part of CU) requires between six and eight million liters daily to sustain its academic, administrative, cultural, and sports activities. This demand makes CU a microcosm of Mexico City’s water dynamics, where efficient supply management is a permanent challenge.

Micrometer in a University City building used for determining water consumption.

 Eduardo Hernández

Supply comes from underground sources and is disinfected with sodium hypochlorite to guarantee its quality. The water is then stored in tanks and distributed by gravity to the buildings on campus. Once used, the residual flow is treated and reused in irrigation of green areas, complying with current regulations for direct contact (NOM-003-SEMARNAT-1997). This integral cycle allows optimizing consumption, reducing waste, and promoting a culture of co-responsibility among the members of the university community.

PUMAGUA’S ORIGIN
PUMAGUA was consolidated in 2008 by agreement of the University Council, with the aim of establishing an efficient and transparent management of water resources in the university. In the beginning, the priority was to know the volume of water used on campus. To this end, with the Hydraulic Balance area, macro-metering systems (a technique that allows quantifying the volumes of water at the main points of supply and distribution of the system) and micro-metering (to record specific consumption in buildings and dependencies) were installed. This scheme facilitated leak detection and detailed analysis of consumption patterns.

After achieving more precise control over the amount of water used, the program incorporated quality monitoring. The quality area is technical and is responsible for the constant monitoring of physicochemical and bacteriological parameters to ensure that the resource is suitable for human consumption, thus protecting the health of the community and guaranteeing the human right to water.

BY INVOLVING STUDENTS, ACADEMICS, AND WORKERS, PUMAGUA PROMOTES THAT THE UNIVERSITY COMMUNITY BECOMES A CO-PARTICIPANT AND CO-RESPONSIBLE FOR THE CARE AND EFFICIENT USE OF WATER RESOURCES

Subsequently, the area of Promotion of Social Participation was formalized, with the mission of reporting transparently on the actions and results obtained, transforming technical efficiency into a shared culture. By involving students, academics, and workers, PUMAGUA promotes that the university community becomes a co-participant and co-responsible for the care and efficient use of water resources.

MONITORING STRATEGY
PUMAGUA systematically monitors the use and management of the supply on campus. The water consumption in CU is quantified by macro-metering systems located at the sources of supply and at the entrances of the hydraulic sectors, as well as by micrometers installed in the dependencies. The analysis of this data makes it possible to identify leaks or atypical consumption. Specialized equipment such as the gas geophone and the portable ultrasonic meter are used for the spot detection of leaks, which facilitate detection in less time and reduce the loss of flow.

Water quality measurements are carried out in situ with portable equipment, while microbiological analysis is carried out at the National Laboratory of Sustainability Sciences at UNAM’s Institute of Ecology, using membrane filtration to identify bacteria that indicate fecal contamination in the water. The quality area systematically verifies the presence of free residual chlorine throughout the hydraulic system, from extraction wells and storage systems to consumption points in dispensers. The results are evaluated based on the criteria established in NOM-127-SSA1-2021.

For its part, the area of Promotion of Social Participation articulates communication and dissemination actions aimed to transfer technical knowledge to the university community. This is achieved through the organization of events with massive participation, focused attention to academic sectors, and the use of digital platforms for the dissemination and extension of knowledge.

CONTRIBUTIONS TO WATER MANAGEMENT
Hydraulic Balance
Thanks to the collaboration between PUMAGUA and UNAM’s General Direction of Construction and Maintenance (DGOC), it was possible to reduce the extraction in CU, from 120 to 80 liters per second between 2008 and 2025. At the same time, the micrometer network increased from 26 to one 144 units during that period.

It is currently possible to record average consumption by dependency and identify physical losses or atypical consumption in a timely manner. These incidents are notified to the corresponding dependencies and technical support is provided for their attention.

In addition, PUMAGUA managed the replacement of nearly 5000 pieces of sanitary furniture with low-consumption models. This action is complemented by a training program aimed at maintenance personnel.

Leak Detection 
Once PUMAGUA, with support from DGOC, managed to capture the main drinking water network of CU on a map, it was possible to sectorize the system into five hydraulic zones (map 1). This action allowed a more accurate diagnosis, identifying leaks equivalent to approximately 50 liters per second. Thanks to inter-agency collaboration, that volume has now been reduced to 40 liters per second.

Map 1. Sectorization of the hydraulic network in University City.

 Elaborado por Nallely Vázquez. Software QGIS (versión 3.32.0 Lima)

At the same time, the control of physical losses within the buildings has shown a favorable trend (Figure 1). The annual average of the lost flow decreased from 10.2 liters per second in 2024 to five in 2025, with a projection of additional savings of two liters per second by the end of 2026. These advances are reflected in the flows recovered through the repair of leaks reported monthly by PUMAGUA, results that have been possible thanks to the use of geophones and ultrasonic meters, as well as the coordinated work between DGOC and university dependencies.

Figure 1. History of leaks detected in the facilities

The orange bars represent a 50% decrease in flow rate over the last year.

 Elaboración propia

Water Quality 
Based on field measurements, it was determined that about 80 percent of the water that enters the network has between 0.2 and 1.5 milligrams per liter of free residual chlorine, which complies with the regulations. Therefore, the disinfection process works adequately in most of the hydraulic system (Figure 2). When chlorine is below 0.2, it is usually due to operational causes. In this situation, the DGOC is notified, the corresponding adjustments are made almost immediately, and the chlorine dosage is normalized. Similarly, if concentrations above 1.5 milligrams per liter are registered, a warning is given, although this situation is not alarming. According to the Center for Disease Control and Prevention, concentrations below four milligrams per liter are considered safe in drinking water. Excess chlorine can be harmful at concentrations greater than four milligrams per liter (CDC, 2024); it should be noted that these levels have not been detected on campus. The average level of residual chlorine is 0.91 milligrams per liter, within the limits established by Mexican regulations.

Figure 2. Level of compliance with water disinfection standards at the University Campus

The standard is met when free residual chlorine is between 0.2 and 1.5 mg/L.

 Elaborado por Nallely Vázquez, gráfico basado en datos de campo de PUMAGUA. Software RStudio , paquete ggplot 2 (versión 2025.05.0+496)

Microbiological analyses confirm the absence of bacteria that indicate fecal contamination, ensuring that the supply distributed on campus is fit for human consumption. These results coincide with the results of analyses carried out by certified laboratories, which corroborates compliance with quality standards.

On the other hand, access to drinking water on campus has expanded, reaching 228 dispensers by 2025. As part of the dissemination campaigns, a digital map was developed that allows each point to be located and includes information on the concentration of residual chlorine, the corresponding dependency, and a reference image. Likewise, the platform allows to generate a route on Google Maps to facilitate the arrival at the selected point (map 2). This tool promotes the safe hydration of the university community and, at the same time, contributes to reducing the generation of single-use plastics.

Map 2. Route to hydration, tool generated by PUMAGUA.

 https://www.pumagua.unam.mx/ubica_bebedero.html

Promotion of Social Participation
The main initiative of the communication area is the University Water Festival, which has been consolidated as an emblematic action of PUMAGUA to promote water culture throughout the community. These actions have promoted responsible use practices and have strengthened more informed management among the members of the university.

OPPORTUNITY AREAS
Monitoring water consumption and quality must advance at the pace of new technologies; therefore, it is essential to incorporate real-time measurements and predictive tools based on artificial intelligence. In addition, it is a priority to strengthen intra-institutional collaboration to consolidate a comprehensive model that optimizes the management of the resource from extraction to reuse. As one of the objectives for 2026, it is explicitly proposed to transfer and adapt the experience developed by PUMAGUA in CU to selected external UNAM campuses through pilot projects, to validate, adjust, and scale successful solutions.

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