Chile has an average annual runoff availability of 53,952 m³ per inhabitant. However, the distribution of freshwater resources is highly uneven (Aitken et al., 2016). The northern regions are arid, while the south has abundant rainfall. This variation is attributed to the country’s long latitudinal span of 6,400 km, stretching from 17°30′S and 56°30′S, as illustrated on the map in Figure 1. The northern regions’ natural deficit results in yearly water availabilities of less than 1,000 m³ per inhabitant while the south’s availability overpasses 10,000 m³ per inhabitant (Valdés-Pineda et al., 2014). Chile is supplied with 42% of surface water, 56.6% of groundwater and 1.5% of seawater (Superintendencia de Servicios Sanitarios, 2023). As seen on the graph in Figure 1, the southern regions exploit the abundantly available surface water originating from streamflow. In the central regions, streamflow quantities and demand are similar. Therefore, freshwater originates from both available surface water and groundwater sources (Valdés-Pineda et al., 2014). Although all urban wastewater is treated in the nation, only 5.5% is treated for direct reuse. Of the remainder, 21.3% is disposed of into the sea, and 73.1% is discharged into continental water bodies (Superintendencia de Servicios Sanitarios, 2023). The Sectoral Agenda for Sanitation 2030 is implementing a new law to facilitate water recycling to sustain the urban growth and increase resilience (Superintendencia de Servicios Sanitarios, 2020; Herrera-León et al., 2022). The increasing demand of water in the Atacama Desert, aside from urban growth, is driven by the water intensive mining activities. This increasing economic development and freshwater use are directly related. However, water demand highly surpasses the little amount of available streamflow, necessitating reliance on groundwater to meet all needs, but the overexploitation of groundwater is depleting the resource at an alarming rate (Valdés-Pineda et al., 2014). Reverse osmosis is therefore becoming more common to increase water security, particularly in the Antofagasta and Atacama region (as illustrated in Figure 1) where copper and lithium are extracted, which are extremely water intensive (Sola et al., 2019). Around 80% of all desalination plants in Chile are for mining purposes (ACADES, 2016).

Over the past decades, almost half of all socio-environmental conflicts in Chile were directly related to water issues, primarily linked to droughts and the depletion of aquifers, as well as inadequate water management and governance (Escenarios Hídricos, 2030, 2019). The country’s Water Code, enacted in 1981, has long prioritized privatization. While there have been some reforms in recent years, these changes have not been sufficient to address the inequalities affecting those outside extractive industries nor the challenges induced by climate change (Julio et al., 2024). Nonetheless, according to the yearly assessment of the SISS, 99.94% of urban residents have access to potable water, with 97.5% connected to the distribution network (Superintendencia de Servicios Sanitarios, 2023). Although Chile’s urban water infrastructure has been successful in coverage and access, climate change poses significant challenges to future water management (Madeira, 2022). The deficiency and decreasing quality of freshwater requires resilience strategies. This imposes mitigation and adaptation strategies across supply, demand, infrastructure, and urban planning, which results in higher water tariffs due to the significant investments needed (Molinos-Senante, 2018). To balance cost and reliance, nonconventional water supplies are a viable solution. Such self-sufficient and sustainable sources include rainwater collection, water reuse and recycling, and in arid environments where the situation is most critical, fog and dew harvesting (Rygaard et al., 2011; ARUP, 2018).

AH is located in the Tarapacá region of the Chilean Atacama Desert, 9 km east from Iquique, on a plateau of the coastal mountain range, about 500 m ASL. The city occupies a total surface of 574.6 km² and a total length of 11 km from north to south. On the west, it borders the cliff overlooking Iquique, while the other three sides are surrounded by hills exceeding 1,000 m ASL (Ilustre Municipalidad de Alto Hospicio, 2022). AH is located within the hyperarid region of the Atacama Desert, which comprises of a (semi-)arid to hyperarid continental strip along the southern Peruvian and northern Chilean coastline (Lobos-Roco et al., 2024). The extreme aridity is characterized by an annual average precipitation of less than 1 mm, as recorded by the weather station at the Diego Aracena airport (Mikulane et al., 2022). The desert is framed by the Andean Cordillera on the east and borders the Pacific Ocean on the west (Azua-Bustos et al., 2022). According to the Koppen-Geiger classification system, this area has a cold desert climate, annotated by BWk, which implies that the mean annual temperature is lower than 18°C, and high rates of evaporation over precipitation are present (Peel et al., 2007). There are numerous factors that cause extreme aridity, depicted in Figure 2. The Pacific anticyclone, a high-pressure area, forms atmospheric stability that prevents the passage of frontal systems originated from the south. Humid masses coming from the Amazon Basin are obstructed due to the Andean Mountain chain, referred to as the rain shadow effect. The Humboldt current at the barrier of the ocean and the continent displaces cold waters from south to north, reducing sea water temperatures and thus, evaporation (Schween et al., 2020; Azua-Bustos et al., 2022). The high permanent presence of this marine atmospheric moisture results in the formation of fog and dew in the coastal and adjacent inland valleys of the continent. As shown in Figure 2B, the northern Chilean coastline consists of a narrow littoral plain followed by a steep cliff called the coastal mountain range with peaks of 1,300 m ASL. Warm air masses above the cold ocean form low, and extended stratocumulus clouds are advected by the wind from the east towards the continent, leading to advective fog touching the coastal mountain range at heights ranging from 500 to 1,300 m ASL (Lobos-Roco et al., 2024). Therefore, a more precise classification for the fog-loaded Chilean coastal region of the Atacama Desert according to Koppen-Geiger is BWn, with n referring to fog (nebel in German), meaning a “coastal desert with abundant cloudiness” (Cereceda et al., 2008). This non-rainfall resource is essential for biodiversity. Up to 10 km inland, concentrated vegetated island with endemic flora called “fog oases” in Chile are found. They serve as an excellent indicator for fog presence (del Río et al., 2018; Mikulane et al., 2022).

AH’s emergence is closely related to its role as a peripheral area to Iquique. Initially in the 1980s, it developed as a destination for impoverished groups who settled through informal settlements. Over time, it attracted urban migrants due to both its low land values and its proximity to Iquique’s thriving economic opportunities in mining and trade around the ZOFRI free trade zone (Fernández Labbé, 2023). From the 1990s, government housing policies massively promoted the development of subsidized housing projects, further expanding AH despite its initial lack of infrastructure and services (Mansilla Quiñones et al., 2020). By 2002, the commune had grown to 50,000 residents and in 2004, it officially became a municipality (Figueroa and Fuentes, 2009; Ilustre Municipalidad de Alto Hospicio, 2020). In December 2023, Iquique and AH formed a metropolitan area. A “Metropolitan Area” is a territorial extension formed by two (or more) municipalities in the same region with shared urban infrastructures and services, and together exceeding 250,000 inhabitants. This allows for shared public policies and investments led by the municipalities and the Regional Government of Tarapacá (Ministerio del Interior y Seguridad Pública, 2023). AH and Iquique are home to three-quarters of the total population living in the Tarapacá region, with AH containing around 113,000 inhabitants in 2017, according to the national Chilean census “INE”. The population was projected to reach 143,300 by 2024, and around 178,800 by 2035. From 2014 to 2019 the numbers of foreigners tripled accounting for 18.4% of the inhabitants of AH in 2021 (Jara-Labarthé et al., 2021; Biblioteca del Congreso Nacional de Chile, 2023; Gobierno Regional Tarapaca, 2023). Moreover, the arrival of migrants after 2020 furthered the development of a nonformal housing market of irregular plots until today. According to the National Migration Service, about 24,000 visas were granted in the commune in 2020 and 2021 (Fernández Labbé, 2023). The urban expansion from 2004 to 2023 is demonstrated in Figure 3.

Informal settlements are part of the expansion of AH. A study by TECHO-Chile and CES in 2022–2023, identified 63 informal settlements in the form of encampments in the Tarapacá region, with 46 located in AH, housing 10,079 families in precarious conditions. The highest concentration is in the El Boro sector (northeast AH). In contrast, Iquique has 11 encampments. Notably, only 1.6% of these settlements are formally connected to the water distribution network, 75.4% receive water via trucks, while the remainder relies on punctures to the public network (TECHO-Chile, and CES, 2023). These settlements along with the further urbanization and influx of migrants created complex social issues exacerbated by the lack of services, which generates a strong dependence on Iquique. Additionally, the population suffers from a lack of quality public spaces, and despite of the existence of infrastructures, it is of low quality. According to the National Socioeconomic Survey (CASEN) in 2015, 23.3% of AH’s inhabitants experienced multidimensional poverty (Mansilla Quiñones et al., 2020). Although more recent statistics for AH are unavailable, CASEN reported that multidimensional poverty in the Tarapacá region was 19.4% in 2015, rising to 24.3% in 2017, and slightly decreasing to 23.8% in 2022 (Observatorio Social, 2022). Nationally, the multidimensional poverty also decreased from 20.3% in 2020 to 16.9% in 2022, largely due to government support (UChile, 2023). Nonetheless, AH’s poverty is reflected in its average income compared to the nation and its neighboring city Iquique. In 2022, the average national income was $USD 760, with Tarapacá averaging $USD 747, Iquique at $USD 877, and AH at $USD 560 (Durán and Kremerman, 2023). In 2023, the national number rose to $USD 837 and Tarapacá to $USD 820 (INE, 2024).

Fog is a cloud that touches the ground comprised of water particles of 1–40 microns, locally decreasing visibility to less than 1 km. The presence of mountains, its orientation, and wind are important to efficiently harvest fog water (Schemenauer et al., 2022). Fog formation is found along the arid western coast of Africa, the Canary Islands, the Arabian Peninsula, the coasts bordering the Pacific Ocean, and in semi-arid tropical highlands where rain is seasonal such as in Guatemala, Colombia and the Philippines (Molina et al., 2008; Balaguer et al., 2011; Suau and Zappulla, 2015; Schemenauer et al., 2016; Zamani et al., 2021).

Fog harvesting is a passive, low-cost, and low-maintenance approach to obtain fresh water. A mesh suspended vertically toward the predominant fog-loaded wind intercepts droplets whereon they coalesce and fall into a gutter. The most widely implemented and installed collectors are Large Fog Collectors (LFC) with a fog harvesting surface of ten by four (variable) meters. The most used interception surface is a double layer of polyethylene, widely known as the raschel mesh. It is a low-cost product also used as a shade cloth in nurseries and greenhouses (Schemenauer et al., 2022). Most countries that have implemented fog collectors and evaluated its harvesting potential are developing countries (Chile, Bolivia, Peru, Ecuador, Colombia, South Africa, Namibia, Eritrea, central Tanzania, Oman, Yemen, Saudi Arabia, and Morocco) (Fessehaye et al., 2014; Correggiari et al., 2017; Ait el kadi et al., 2024). In the 1980s, a pioneering project was set up in El Tofo, in the Coquimbo region in Chile. Which began as a research project for reforestation purposes, expanded to providing potable water with 100 LFCs (or “atrapanieblas” in Spanish) to 300 inhabitants down the slope. During the fog season, which is approximately from June to November in the region, the village received up to 15,000 L of water per day. Prior to this emblematic project, the town of Chungungo relied on water delivered by trucks (“camiones aljibe” in Spanish) receiving only 10,000 L per week (Fessehaye et al., 2014; Correggiari et al., 2017). The pilot project was seen as a success in terms of research and validation, but after 1 decade, the collectors were degraded due to storms, and lack of maintenance and funding (Edwards et al., 2001; Dale, 2003). Recently, researchers in the Atacama Desert have successfully utilized fog water for hydroponic food production in greenhouse structures in Falda Verde, Chile, enabling the soilless cultivation of lettuce, strawberry, basil, and mint (Albornoz et al., 2023, 2024). While these are among the successful projects for rural areas showing their potential, to date, there is only one known fog water collection project in an urban context. This project, located in the Villa María del Triunfo sector of Lima, Peru, supplies water to 250 households in slums. Nevertheless, the use of fog as a hydric resource has been carried out under the perspective of domestic uses in rural settlements (Fessehaye et al., 2014; Correggiari et al., 2017; Verbrugghe and Khan, 2023b). Many other projects underline the effectiveness of fog water collection in rural settings, demonstrating its potential as a reliable supply capable of delivering significant quantities of water (Klemm et al., 2012).

Fog water collection is measured using the Standard Fog Collector (SFC) proposed by Schemenauer and Cereceda (1994). This device comprises one square meter of double raschel 35%-shade mesh standing at 2 m from the ground. The mesh is connected to a galvanized metal channel at its bottom edge to conduct the collected water into a pluviometer that registers the fog water volumes every 10 min (Schemenauer and Cereceda, 1994). Two SFCs were installed in the urban area and surrounding elevations (Figure 4; Table 1-a), from which the one located at the higher elevation (High SR) includes an all-in-one meteorological station registering data every 10 min. Fog collection measurements were conducted for the first time in AH over a 1-year period, from October 2023 to October 2024. Table 1 summarizes the spatial setting and data type gathered through these in-situ measurements.

To numerically quantify the fog water potential in the metropolitan area of Iquique and AH, we use the AMARU model (Lobos-Roco et al., 2025). Using available routine meteorological data, this model estimates the amount of fog water that can potentially be harvested using SFCs. While detailed information about the model is provided in Lobos-Roco et al. (2025), we describe key modeling details of how the results for AH were obtained. The AMARU model is defined by the following main equation: ∫ t 0 t 1 W h z = r l z u x η   d t where W h corresponds to the modeled fog water harvested at z level, r l is the adiabatic liquid water content (in g m^-3), u x is the perpendicular-to-the collector wind speed (in m s⁻¹) and η is an empirical dimensionless coefficient of efficiency. The model is integrated into a predefined period of time (t ₀ to t ₁ ), at every hour, which can later be integrated into monthly and annual water collection rates, expressed in L m^-2 per day. The model’s objective is to estimate the adiabatic liquid water content ( r l ) in the atmosphere’s vertical column (z). This r l is obtained using data from two meteorological stations (Table 1-b) positioned along a topographic gradient. Once the liquid water content is obtained, we use wind speed measurements from the same stations and use an η of 25% (Riverda, 2011; Carvajal et al., 2020). The result is a vertical column of water harvesting potential ( W h z ). The final step is to combine this vertical column with two remote-sensing satellite products. The first is a digital elevation model at a 30m-spatial resolution, where fog collection height range and flux direction are established. The second is the fog and low clouds (FLC) spatial extension at 2 km resolution, obtained from the GOES satellite following the methodology suggested by Espinoza et al. (2024). In this way, the model displays the distribution of the most probable areas for potential fog collection. The water volumes are integrated into average monthly daily rates.

The model runs with hourly data from 2018 from two meteorological stations: Diego Aracena Airport and the fog oasis of Alto Patache (Table 1). The model has been validated using SFC observations from Alto Patache, a fog oasis 65 km south from Iquique. The comparison showed that the model underestimates observations by 10% (0.5 L m⁻² day⁻¹). In addition to this validation, we have compared modeling results with the observations in AH from the low SR and high SR SFCs. Both low SR data and the model show null fog collection. High SR station shows rates of <0.2 L m⁻² day⁻¹, while the model shows <1 L m⁻² day⁻¹.

The Tarapacá region is comprised of two provinces, Iquique and Tamarugal, with the latter located inland. AH is supplied with potable water from underground drillings located in the Pampa del Tamarugal basin through 72 km of ductile iron pipes (Figure 5). These underground drillings are located at the aquifers El Carmelo (EC) and the “Canchones–Cumiñalla” (Ca–Cu) system (Aguas del Altiplano, 2018a; Aguas del Altiplano, 2018b), which are non-renewable water resources (Santoro et al., 2018).

The Ca–Cu production system consists of a group of 18 drillings, each with an average depth of 110 m. The water is elevated and transported to several water tanks until reaching the “Santa Rosa” water storage tanks in the southeast sector of AH. The water is stored in two tanks of 10,000 and one of 5,000 m³ and distributes water to most sectors in the city. The north of the city called El Boro is supplied from the “El Boro” tank measuring 800 m³, with water originating from the “Santa Rosa” tanks. The water is distributed to the city through a network of feeders and matrices with a total length of more than 151 km, whose diameter fluctuates between 75 and 250 mm. The surplus is transported to the “Alto Hospicio” tanks, which supplies Iquique and consists of two tanks of 5,000 and 2,000 m³. These also receive water transported from the EC system, which also supplies Pozo Almonte inland (Aguas del Altiplano, 2023a; Aguas del Altiplano, 2023b).

Until 2019, wastewater was collected and treated at a plant consisting of four aeriated lagoons in the El Boro sector. A portion of this treated water was used to irrigate nearby olive groves, while the remainder was discharged to Iquique (Aguas del Altiplano, 2018a; Aguas del Altiplano, 2023b). However, the treatment plant was eventually closed due to persistent odor issues affecting local residents. Although initially located away from the center of AH, the area had become increasingly populated after 2011 (Agenda Sustenable, 2020). Currently, wastewater is transported to Iquique, where it undergoes preliminary treatment through screening to remove debris, passing through coarse and fine screens, as well as a sand trap, before being disposed of into the Pacific Ocean (Aguas del Altiplano, 2018b).

Regarding drinking water consumption, AH was projected to use 159.55 L day⁻¹ per inhabitant in 2023. This implied a daily consumption volume of 17,112 m³ for approximately 107,256 inhabitants. Aside from population growth by 2037 (144,426 inhabitants), numbers indicate that the consumption will increase to 164.08 L day⁻¹ per inhabitant, resulting in a daily volume of 23,697 m³ (Aguas del Altiplano, 2023b). While the current water distribution network reaches 100% of the population officially living in AH (Aguas del Altiplano, 2023b; Superintendencia de Servicios Sanitarios, 2023), new informal settlements such as camps and land grabs may not be included. The city’s expansion in 2023 has extended beyond its urban limits (Figure 3) partly due to the COVID-19 pandemic, which displaced many immigrants from South America to Chile (Imilán et al., 2020; Alvarado Peterson and Rojo-Mendoza, 2023).

Our assessment of fog water collection potential indicates that the surroundings of AH, encompassing an area of about 100 km², demonstrate harvesting rates ranging between 0.2 and ∼5 L m⁻² day⁻¹ on an annual average, according to the AMARU model. However, this potential is confined to the mountainous regions at elevations of 700–1,000 m ASL outside AH’s urban limits. In the following subsections, we describe our assessment through in-situ observations and modeling results in detail.

As of 2019, the Ministry of Housing and Urban Development’s Cadastre reported a total of 30 slums outside the urban fringe of AH, housing a total of 3,519 households and 10,301 people. These slums are primarily located in the northern part of the city (see Figure 3). These residents rely on water deliveries via trucks provided by the local government of AH. According to the 2023 Public Account, 300,000 L of water per week were delivered. Regarding the estimated municipal expenditure to meet this water demand, it is projected to be $USD 451 per week, or $USD 23,482 annually, based on the average cost of 1 m³ of potable water in AH in 2023, as mentioned above. Besides, for the population living in slums located inside the urban fringe, the local government issues over 36,000 “water vouchers” per month to more than 10,000 families. The water voucher program is a national public policy for families that allocate at least 5% of their monthly income to potable water and sewage services. The government subsidizes a portion or percentage of the monthly payment for up to a maximum of 13 m³ of potable water and sewage services for permanent residents of both urban and rural areas across the country. According to the data, the local government of AH financed approximately 5,616,000 m³ of drinking water in 2023 (Ilustre Municipalidad de Alto Hospicio, 2023).

The proximity of locations with significant fog collection potential, situated just outside the urban limits, presents a promising opportunity for the installation of large-scale fog collectors, pending further refinement of the data. Theoretically and considering that these locations have a modelled annual average rate of (Figure 8) of 2.5 L m⁻² day⁻¹, 17,000 m² of mesh is needed to meet the weekly water demand of 300,000 L for the urban slums. Distribution could be managed through piping infrastructures or continued delivery by trucks. Important to convey is that given the seasonal variability of fog formation and the rapid peri-urban population growth, fog water is most suitable as a complementary supply. Implementing large storage systems or ponds is necessary to ensure continuity to bridge the seasonal gap. However, during the fog-scarce periods, alternative water sources, such as trucks, may still be necessary.

The United Nations’ New Urban Agenda (2017) highlighted several challenges faced by contemporary cities, including the lack, reduction, and unequal access to natural habitats and green spaces, which are recognized as multifunctional areas that improve people’s health and wellbeing. Green spaces play a fundamental role from an environmental and social perspective. They increase urban biodiversity, reduce contributions to climate change and the urban heat island effect, encourage physical activity, reduce anger, anxiety, depression and stress, improve visual comfort, and increase community connectedness, food security, and social cohesion (Reeve et al., 2015; Ahuja, 2016; Kellert, 2016; Terkenli et al., 2020; Carter et al., 2021; Cree and Robb, 2021; Roe and McCay, 2021). However, water demands for maintaining green spaces in general, are highly dependent on the regional water system (Nouri et al., 2012; 2019; Reyes-Paecke et al., 2019). The hyperarid environment of AH complicates efforts to green the city through precipitation (Sarricolea et al., 2017; del Río et al., 2018). According to data from the Ministry of the Environment (2016), within the context of the “Development of a Digital Climate Database for Chile: Baseline (1980–2010) and Projections to 2050” project (Ministerio del Medio Ambiente [MMA], 2016), AH receives a maximum precipitation of 3 mm, impeding sustainable implementation and maintenance of urban green spaces. Furthermore, society is becoming increasingly aware that continued stress on surface and groundwater sources, commonly exploited in arid climates, is not sustainable (Newman et al., 2017). Aside from local water scarcity, the pressure on the conventional water distribution infrastructure and its availability is increased by industries and population growth (Dirección General De Aguas, 2017; Salinas et al., 2016). Given these factors, the availability of an alternative and reliable water source for maintaining green infrastructure in desert cities—within the broader context of greening urban environments, as outlined in the New Urban Agenda (United Nations, 2017)—is crucial to ensure the sustainable development of cities and communities.

Regarding budgetary limitations for implementing greening initiatives and maintenance, AH is recognized as one of the most affected local governments in Chile by inequalities. It presents a dependence of the Common Municipal Fund on its own income of 70% in the year 2020, concentrating only 0.3% of the communal budgets with respect to the national total. Besides, it presents a low quality of urban life according to some national indexes from the last 10 years (Centro de Inteligencia Territorial de la Universidad Adolfo Ibáñez, 2017; Orellana et al., 2021). Regarding other statistics that characterize AH, the northern and especially the southern edges show low values of social welfare with respect to investments in infrastructure with higher values of daily thermal amplitude, which reflects the need for more green areas or infrastructure; scarce or almost no presence of green areas; low accessibility to public services; and low proportion of health facilities. In its “Public Account 2023” document, which summarizes all administrative actions, the local government reports that it is responsible for irrigating the city’s public urban green spaces. Green spaces in AH covered a total area of 25 ha in 2022, and now exceeds 30 ha, with more than 100,000 L of potable water delivered to several watering committees for irrigation.

Using fog water for irrigation arises as a potentially practical and sustainable solution. To meet the annual water demand of 100,000 L, around 110 m² of mesh would be needed, based on the same annual average rate of 2.5 L m⁻² day⁻¹. The collected water does not require extensive treatment, making it particularly suitable for non-potable uses such as urban green infrastructure. Municipalities could establish systems where fog water is collected in nearby areas with high collection potential and transported via water trucks or piped directly into storage facilities within the city. This approach would allow the integration of fog water into existing irrigation systems, reducing reliance on treated water for non-potable purposes.

Between the 1950s and 1980s, AH was primarily a horticultural hub supplying Iquique. However, the rapid population growth after the 1980s, marked by land seizures and the development of housing projects, replaced its earlier role (Municipalidad Alto Hospicio, 2022). The World Health Organization recommends a daily intake of around 400 g of fresh fruit and/or vegetables per person (Wallace et al., 2020). To meet this, northern Chile relies on import from central Chile or neighboring countries, which results in high prices unaffordable for low-income inhabitants such as from AH (Albornoz et al., 2023). Local food production would be an alternative for supplying the community, but the hyperarid environment of AH restricts water availability and the implementation of agricultural production. This is exacerbated by the poor quality of the soils due to high levels of salinity, limiting the number of crops that can thrive under these conditions (Villanueva et al., 2003). Therefore, soilless production arises as a viable alternative for vegetable production. This technique uses either hydroponic systems or substrate-based production in containers, with its main advantage being that it requires significantly less water than traditional soil-based agriculture (Pomoni et al., 2023). Our findings indicate that fog water is not available during the whole year, however, the implementation of hydroponic systems including storage tanks or even, using the same hydroponic system as a reservoir, would allow for vegetable production throughout the year. The quality of fog water is remarkably good for this strategy, since it presents a very low content of dissolved solids suitable for direct use into hydroponic systems and storage (Albornoz et al., 2024).

Hydroponic agriculture demands an average of 0.5 L day⁻¹ per square meter of ground surface cover with crops (Albornoz et al., 2023). This makes fog water particularly valuable, as even low amounts of captured water can sustain crop growth. In 1 m² of hydroponic lettuce, around 25 to 35 plants can fit, yielding between 3.0 and 4.0 kg of fresh produce in a 30-day period. With an average collection rate of 2.5 L m² day⁻¹, almost 5 m² of hydroponic lettuce (or any other leafy green crop) could be supported, yielding between 15 and 20 kg of fresh vegetables for local consumption in AH. Integrating fog water for activities within the city requires transporting the collected water into urban areas, incurring costs associated with piping infrastructure or transportation. In contrast, using fog water for local food production is more practical, as it can be collected, used, and stored directly at the source. This makes local food production a particularly promising application with low associated water infrastructure costs, and even more interesting for AH, where local fresh food production is almost inexistent.