Alto Hospicio is a city in northern Chile on the edge of the Pacific Ocean. Of crazy growth, its more than 120,000 inhabitants live at the west end of the Atacama desert, the driest in the world. Located in a plain hundreds of meters above sea level, at its feet is Iquique, capital of the homonymous province. Both cities depend on the water that kilometers of pipes and tank trucks bring from the interior of the desert. But competition with mining (the historical copper and the most recent lithium), very intensive in water resources, threatens aquifers. These are not recharged from the last glaciation. Covered by the fog for a good part of the year for a particular location, a group of scientists has launched a project in the city to harvest water. According to their results, published in the scientific journal, using conventional meshes such as attrapanieblasup to 10 liters per square meter of mesh and day could be achieved.
“It is a stigmatized city,” says the researcher at the Universidad Mayor (Santiago de Chile) Virginia Carter. “It is born from disorderly urban planning, lack of infrastructure, with one of the rates of green areas by lower inhabitants and the highest in crime, with people displaced from Iquique, it is in the imaginary of the Chileans as a hard place for Live … “, adds Carter, who immediate Fog ”, complete. And that mist that arrives from the sea, but never precipitates, is the one they have taken advantage of.
Between October 2023 and October 2024, the group of researchers led by Carter recorded the fog water that captured two panels placed at two ends of Alto Hospicio. They obtained figures near the millimeter per day per square meter of panel. The context explains the figure: the city must be one in which it rains the planet least. There they do not have a weather station, but the closest, that of the Diego Aracena airport, nine kilometers, records annual average rainfall of 0.8 millimeters, but a year. The improvement is more than remarkable. The work did not stay there, the objective of the two panels was to validate a model to climb the idea by placing dozens, perhaps hundreds of attrapanieblas in the desert plain surrounding the city. Based on satellit data, the weather stations of the environment and the dice of the panels, this climate model estimates that up to 10 millimeters per day per square meter could be collected.
It is not the first time that fog is used to obtain water in arid areas. And less in Chile. From this country was the physicist Carlos Espinosa, the first to patent a system of collectors seventy years ago. It was also in the Andean country where, based on Espinosa’s ideas, a network of 100 collectors for fog water and providing the small community of Chungungo was projected and set up for the first time. “This rural village was supplied for almost ten years,” says Carter. “They had running water for the first time, the washing machines arrived, the dishwasher … which indicates that technology does,” he adds. The population of the place doubled in a few years, but in the end, they forgot the attrapanieblas. “They were offered the water of a desalination company. It is what has happened in other parts of the world where the governing of fog water has failed: lack of governance to maintain it and the expansion of desalination plants, ”ends the Chilean researcher. And plants.
The researcher at the University of Valencia (Spain) David Corell, who knew the project of Alto Hospicio, recalls that the objective of these plans cannot be to cover the drinking water needs of a population of 100,000 people or more, such as that of The Chilean city. “But it can function as a supplementary source.” Corell has dedicated his entire research career to water ,. “We started in 2003. Technology is very simple, has practically not changed since the first essays in Chile. It is simply to expose a mesh to the wind, like a mosquito net, which is breathable to the wind. When the fog crosses that mesh, the water droplets adhere to it and fall, collecting it with a channeling, ”he explains.
The doctoral thesis of Corell, of 2015, was part of a series of projects with state support to estimate. Over ten years they placed a hundred collectors in different places, from Girona, in the pre -pyrineo, to Cabo de Gata, in Almería. “In the best locations we took over 5 liters per square meter and day. You multiply that by 365, and you can put as many meters as you want, ”says the scientist. But the project did not continue. As he says, “we have no limitations as extreme as in other areas” but Corell adds that, “where basic needs are covered, we have always thought that environmental use should be given.” So they did an experiment in the Valencian municipality of Ayora where they used the panels to capture water with which to water inside a forest restoration program after a fire. “The first years, it is essential that the seedling receives some rainy contribution in summer, but the summer rains are being lost, so if they do not achieve a minimum, the forest restoration fails.” Thanks to the mosquito net, they had a percentage of survival of the trees close to 100%.
In the El Andén Barranco, in the North Gran Canaria, the success percentage of Canarian Madroño, Brozo and other species in Laurisilva has been 86%. The area, also punished, has gone through different attempts for reforestation. “We had to climb the water from the coast to more than 1,000 meters high in Cubas,” says the coach of Environment and Climate Change of the Cabildo de Gran Canaria, Rainero Brandon, one of the initiators of which, supported by the European Commission And scientific institutions such as CREAF, GESPLAN and Cabildo himself, rehearsed several collection systems in an abandoned quarry in Catalonia, a burned forest in Portugal and the Canary Islands. In the ravine the platform imitated nature, in this case to the pines and the way of needles of its leaves. “Meshs need maintenance, break with the wind, no acicles,” says Brandon. In addition, they not only steal water from the fog, they also do it to dew. Started this new attempt in 2020 and finished at the end of 2024, the European project has become a Canarian program and are taking their panels where reforestation begins.
Carter, the Chilean researcher, and her group will present in the coming weeks a map with the northern half of Chile areas where it would be feasible to put attrapanieblas. SAbe that cannot deploy as many panels for fog water to become the main source for cities inhabitants such as Alto Hospicio. But he wants to emphasize that, “through pure science, we can raise awareness in the decision makers so that the fog is included in the public policies of our country and is considered a complementary resource.”
