How Chile's fogcatchers are bringing water to the driest desert on Earth

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The Camanchaca presents a unique opportunity for those suffering drought in Chile's north(Credit: Nick Lavars/Gizmag.com)

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"It's easy for people in the cities. They don't have to think about it. They turn on the tap and they have water to wash and water to drink. Here, access to water is a much more complicated issue." Agricultural expert Daniel Rojas might have been talking about any place on Earth where water is hard to come by, but his words have a particular salience in Peña Blanca, Chile. The remote, drought-stricken community lies on the fringes of an expanding Atacama Desert, the driest (non-polar) desert on Earth. Parts of this parched, desolate land have never seen a single drop of rain. With more than a million people scattered across fishing villages, towns and coastal cities throughout, when it comes to water the resourceful folk of Chile's north have had to make do with very little. But a storied mist known as the Camanchaca rolls in from the Pacific, and each time it sweeps across the desert hills it spatters strategically placed nets with microscopic droplets. Each speck is entirely insignificant on its own, but through a cheap, cleverly designed system they pool into tanks for farming, preserving native vegetation, and even producing beer.

Rain is incredibly scarce in the north of Chile. The fog assumes a dense, pillowy presence as it sweeps across the desert hills, but its particles are too fine to form droplets of rain on their own. The country has suffered a severe drought since 2007, threatening critical industries like copper mining of which it is the world's largest exporter. As the shortage of rainfall enters its eighth year, geographers hold grave fears that the desert will permanently expand south to the capital of Santiago, swallowing up historically fertile farming land as it goes.

But where those in the capital can count on reserves of water from the glacier melt that trickles down from the surrounding Andes, the people of the north resort to less ideal means to source water, most of which are inefficient, and none of which are cheap. The 200,000 people that populate the mining city of Antofagasta rely on desalinated water from the ocean, while more modest townships count on water from underwater basins or have it shipped in on trucks. And the smaller these communities get, the more problematic and less financially viable sourcing water becomes.

This is no more evident than in the tiny fishing communities that dot Chile's coastline, where the desert meets the sea. The impoverished anglers that live in these little coves survive on around eight liters (two gal) of water each day, meaning showering isn't an option. Because of how isolated they are, building a pipeline to give five fisherman access to tap water, for example, would be prohibitively expensive. So Chile's geographers, engineers and academics are looking to the Camanchaca for cheaper and more sustainable answers.

Making fresh water out of thin air

The famous Camanchaca is never far away in Chile's north. There are times when its sheer density envelopes all that the eye can see, stretching for miles in every direction almost as if to tease the bone-dry terrain underfoot. The droplets of water that it carries measure between 1 and 40 microns each, too fine and light to fall to the ground on their own.

But as the Camanchaca comes into contact with boulders and plants, its tiny droplets collide with vertical surfaces like upright rock faces, long leaves and cactus thorns. Here they accumulate into larger water droplets with enough mass to fall to the ground, wetting the earth underneath and providing sustenance to vegetation.

As many as 1,000 years ago, the native people of the north would try and recreate this process to draw potable water from the mist. The tools at their disposal were a little more primitive than those around today, but they worked. They would suspend animal skins from trees to catch the droplets of water, which would then accumulate in small vases underneath. Similar techniques were known to have been used in neighboring Peru and as far away as Spain's Canary Islands. During Chile's wars throughout the 19th century, dehydrated soldiers would tie pieces of cloth to the tips of their rifles to collect water during the night.

Then in the 1950s, an enterprising physics student at the University of Chile named Carlos Espinosa started to wonder how methods to harness the moisture of the Camanchaca could be modernized. He sought to improve on these early techniques by building and testing various prototypes of large brass structures that bore sheets of nylon meshing as a means of collecting condensation. When these devices started to funnel gallons of water into his collection tanks, he knew he was onto something. These would form the very first versions of Chile's fogcatchers.

More than a drop in the ocean

Espinosa's efforts to refine the fogcatchers continues to this day, but he is not going it alone. For the past 30 years, geographer Pilar Cereceda has been researching how to best harvest water from the Camanchaca, building on the knowledge Espinosa acquired through his time working in the desert. In her capacity as a tenured Professor at the Institute of Geography at Pontifical Catholic University of Chile (PUC), she spends her days dreaming up ways to advance the science behind trapping fog.

"In Chile, we aren't the true pioneers of collecting water in this way," Cereceda explains to Gizmag, referring to the early, rudimentary fogcatchers in other parts of the world. "But we are pioneers in one sense, because we dared to create a project of a grand scale."

In 1985, Cereceda and a team of geophysicists from PUC came up with a plan to build a huge array of fogcatchers along a ridge line overlooking a small desert community called Chungungo. Chile's National Forestry Corporation got onboard and, importantly, they then won the financial backing of Canada's International Development Research Center.

"The water that used to arrive to this community would come in on trucks, maybe once a week," says Cereceda. "The people would be left waiting, not knowing when the trucks would come, or if they would come at all."

The venture, which came to be known as The Camanchanca Project, saw 50 large fog collecting nets constructed on the mountain ridge. The initial idea was that these would produce water for a nearby forestry plantation, but at the same time serve as a proof-of-concept for the technology. The cheap nets made from polyolefin, a cheap and widely available plastic, yielded such large amounts of water that in 1992 funds were provided to build a pipeline down to the people of Chungungo. Accompanied by a storage tank and a distribution system, the fog collection then brought running water to 100 Chungungo households for the first time.

"After the project, the water arrived through pipes into tanks, directly to the house where you could turn on the tap and drink water from the fog," says Cereceda. "With this you had water for showering, you had water for animals, you had water for everything. In this sense, Chile is very important. Because this project was very successful, people came from all over to report on it and it opened the idea to the world. They could see that this was a case where the system had worked."

The Camanchaca Project provided a blueprint for similar systems around Chile, as well as in Peru, Ecuador, Haiti, Yemen, Nepal, Oman, and even developed regions like the Californian coast. Due to its low-cost and great accessibility, the polyolefin material used in the early system currently remains the most practical, but that doesn't mean other bright minds aren't looking at improving it from every angle.

Room for improvement

Just down the hall from Cereceda's office at PUC, Professor Pablo Osses oversees the school's Institute of Geography. His research focuses on making the system more efficient by studying its environment, rather than its design. For 20 years, he has been investigating the climatology and meteorology behind the Camanchaca, looking to determine exactly how much potable water it could bring and where to station nets in order to best trap it.

"Through satellite remote sensing, I am working to model the behavior of the cloud on a very small scale, in small sections," Osses tells Gizmag. "In order to learn with more precision how much water we can produce, where we can produce it and when. These are the three fundamental questions."

While tracking the Camanchaca as it moves across the desert is Osses' domain, others are very much looking at what changes to the nets themselves could facilitate better water yields. At the edge of this research is a team from MIT's School of Engineering, which is collaborating with PUC to improve the design. This means experimenting with everything from the size of the holes to the size of the fibers and the types of materials used to coat them.

Their research has drawn them toward smaller filaments and smaller holes. MIT has reported that in their current state, the fogcatchers can trap around two percent of the water in a mild fog. It claims that a finer mesh could pull 10 percent, or possibly even more. Atop a hill overlooking Peña Blanca, it has stationed a series of five sample fogcatchers featuring slightly different compositions. Powered by a single solar panel, data is collected on the catchments of these varying designs and relayed back to PUC in the capital. By studying the capabilities of these marginally different fog-catching systems, it is hoped an optimal approach can be settled on and then replicated on a much larger scale. But just because the yield more water doesn't necessarily make them the most cost-effective.

"The costs must be kept low for fog-catchers to remain a good solution for producing water and the current system is very cheap," says Osses. "Better versions do exist, but they are a lot more expensive. They produce a little more water, but they also cost a lot more and for this reason they don't make sense."

Because the availability of the fog shifts between the hilltops and the valleys, and the dry months and the humid months, working out where to place the nets has been something of a guessing game so far. Osses hopes that by combining satellite imagery with remote sensors on the ground he can better predict where and when the fog will appear, directing more efficient collecting installations of the future. For him, this is the best area to channel his energy in an effort to improve the efficiency of fog-harvesting.

Fog catching in action

Daniel Rojas is a community leader and president of Fundacion un Alto en el Desierto, an environmental organization that aims to address problems associated with desertification in the region. We meet him at a rusty gate on the side of the Pan-American Highway, around 250 miles north of Santiago. He invites us aboard his four-wheel drive, warning the terrain ahead might be a little much for our rental car to handle. A short, very bumpy trip later we come to a hilltop scattered with shrubs, unkempt grass and large arrays of fog catching nets. This is where freshwater is harvested for the people of Peña Blanca, a modest scattering of houses and farmland that can be spotted down in the valley below – fog permitting.

"In this region, especially here in Peña Blanca where water is becoming more scarce all the time, we are going through a very large period of drought," says Rojas. "It is a drought that could be permanent. All the time the desert is consuming more land and we are experiencing the effects of it. This region of Chile is one with many of problems of desertification."

Since 2005, Peña Blanca's fogcatchers have gathered water with the aim of preserving the natural vegetation in this area. Following some modifications, Rojas has come to a design consisting of panels with an area of 3 sq m (32 sq ft). He says this is an optimal size for water production and maintenance, which involves replacing the nets approximately every two years. His entire setup consists of around 220 sq m (2,368 sq ft) of mesh across 24 fogcatchers, with each square meter producing a little over five liters (1.3 gal) of water daily, amounting to a total of more than 1,000 liters (264 gal) per day. The water was initially channeled toward the native vegetation in the area surrounding Peña Blanca, but it's now beginning to trickle down to the people themselves.

"To begin with the water was used for reforestation, but through this invention we were able to produce water for animals to drink," he says. "We could bring it to parts of the community to be given to animals, primarily the sheep that belong to small-time farmers. And today, we now have a system with communal tanks, where it is used for human consumption. So now, these nets serve the purpose of watering vegetation, providing drinking water for the animals and for use by the people."

While the fogcatchers are giving the people of Peña Blanca access to water for basic needs, they are also giving rise to a certain entrepreneurial spirit. It was here in 2012 that two brothers from the nearby city of La Serena built a brewery with a slightly different flavor. With fogcatchers of their own set up on the hills overlooking the village, Marco and Miguel Carcuro harvest moisture from the Camancha for the water-intensive process of beer production.

We arrive at Peña Blanca's Atrapaniebla artisan brewery to find Miguel Carcuro lunching alone in a back room. Over a steaming bowl of soup and a sampling of his Camanchaca-inspired beer, he begins to tell us the story of how the world's only fog-harvesting brewery came to be. With basic items bought from local hardware stores, he and his brother have built contraptions that generate enough water to brew 3,000 liters (792 gal) of beer every month, which is enough to fill 9,000 bottles. He tells us the process requires around 500 liters (132 gal) of fogwater for every 250 liters (66 gal) of beer. He is also quick to emphasize that the purity of the fogwater gives his brews a special taste.

"The recipe is very similar to other styles, the types of beer we brew here are a Scottish ale and a brown ale," says Carcuro. "The only difference is that the Scottish ale is a little lighter, because people that drink beer in the north of Chile live in a very warm climate, so they need a lighter beer that is easier to drink. But in the south, where the climate is colder, they drink fuller bodied beers with a higher concentration of alcohol. So we make different styles of beer to increase business."

When it comes to optimizing his methods, Carcuro follows the Osses line of thinking. He tells us that where you choose to place the nets is more important than the quality of the nets themselves. So rather than investing in trying to improve the design, he says using cheap, locally sourced materials is the best course of action. It also makes maintenance easier than if he was to import items like mesh, wood and guttering from overseas.

"If I need more water I can just make more fogcatchers," he says.

The Atrapaniebla artesan brewery is small, but it is attracting its share of attention. Carcuro tells us that he has had visitors from Vietnam, Italy and Russia, in addition to a lot of local interest. With large, visible "Atrapaniebla" signs erected along the Pan-American Highway, Carcuro's brew draws in inquisitive and thirsty holidaymakers returning to Santiago from the beaches dotting Chile's northern coastline.

"Let's say there was an aquatic park in the middle of the desert," he says. "There would be some attraction there because there is a huge contrast. We have seen this happen with our brewery, because normally a brewery is like a big pump that requires huge amounts of water from an underwater basin or river. Learning that a brewery can exist in the desert is a bit of a shock to most people."

Blue sky ahead?

For those that currently rely on the fogcatchers, low-cost, widely available materials remain the most practical tools with which to harvest water from the mighty Camanchaca. But Osses, Cereceda and a team of engineers and geographers are working every day to improve the system. Cereceda tells us that this might mean turning back to nature to determine which objects are best able to gather water, be it trees, rocks or otherwise.

"We are looking at every aspect in order to develop at a better fogcatching system," says Cereceda. "Hopefully one day we will have the ability to compete with the desalinated water from the ocean, because that method is expensive. But we do need fogcatchers that are more efficient."

She has high hopes for the fogatchers, but Cereceda is taking a long view with how much time may pass before their potential is fully realized, drawing comparisons with the emergence of other cheap, environmentally friendly technologies.

"Windmills are very old," she says."But then 100 years pass and they are using them for things like grinding grains and pumping water from underground. And now with the help of science, we have very tall windmills capable of producing enormous quantities of electricity."

In Cereceda's view, fogcatchers evolving in a similar fashion is not beyond the realms of possibility. But rather than fossil fuels and solar power, the measuring stick in its progress will be the tremendously expensive process of desalinating water from the ocean.

"The cost for one cubic meter (35 cubic feet) of desalinated water is around one dollar (US)," she explains. "We need to be able to produce fogwater at the same price. But we have a huge advantage in that we don't need energy. With desalination you need energy to extract water from the sea, for reverse osmosis, to pump it and then you have all the salt left that you need to dispose of. Everything requires energy. With this approach, we are on top of a hill with water running to the cities at the bottom. So through gravity, we could possibly even produce energy."

To spread fogcatchers into new locations, students from PUC work with an NGO called Fogquest. Together they visit remote communities in the north of Chile, first identifying which are most in need of water and then those that have the willpower to adopt new technologies as a means of survival.

Fogquest has built fogcatchers in the city of Iquique and in the remote community of Falda Verde, where the 600 liters (158 gal) of water a day they produce sustains an aloe vera plantation, which brings jobs and profit to the area. But where the fogcatchers may one day prove to have the biggest impact is in the hugely water-intensive process of copper mining.

"The thing is with mining they need water constantly," Cereceda explains. "You can't have a week with no fog and no water. You'd need to calculate which days there won't be fog and store water in tanks. So we need to wait until the moment where we have fogcatchers just like we have solar panels. Just like gigantic surfaces covered in solar panels could come to provide energy for a city, for example."

Cereceda says the idea that solar panels can blanket rooftops to suck energy out of every square inch could also be applied to fogwater and copper mining. She acknowledges that it would require an enormous amount of nets and storage tanks, but insists that she can see it becoming a cost-effective and practical strategy.

"Twenty years ago, it was unthinkable that desalinated water from the sea could be brought inland," she says. "Because you have to pump it, and that takes energy, which is very expensive in Chile. But the miners did it anyway. They brought the water to an inland copper mine even though the cost was very high, because the price they were able to sell the product for was also extremely high."

Cereceda is infectiously optimistic about the potential impact of fogcatchers in coming decades. Though it seems ambitious, she is convinced the humble old nets she has dedicated her working life to will have a lasting impact on her country.

"Yes, I think it is possible. I see a green future for our desert."

We chat to Miguel Carcuro about how he makes beer out of thin air in the video below.

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