Fog Harvesting Turns Clouds Into Crops In Chile – And Offers Lessons For Dryland Africa
There are days in northern Chile when the sky refuses to break. No rain, no storms. Just a thick, cold mist rolling in from the Pacific, slipping over the hills and ravines like a grey blanket. Locals call it camanchaca. For years, it teased farmers – bringing humidity but not the liquid water their crops needed.
On the slopes of the coastal mountain range in the Fray Jorge Biosphere Reserve, that has begun to change. In the Peña Blanca agricultural community, people now stretch high‑density meshes across the Cerro Grande Ecological Reserve and catch the fog itself, drop by drop. The mist beads on the netting, runs into gutters, and flows into a pond – a quiet, ingenious answer to drought and chronic water scarcity.
This is not a science fiction project. It is a working system built over two decades by farmers and technicians with the support of Chilean organisations and the Food and Agriculture Organization of the United Nations (FAO). And its lessons reach well beyond Chile, into the parched hills of Matabeleland South, the drylands of Namibia, and the fog‑kissed Eastern Highlands of Zimbabwe.
How A Chilean Community Turned Fog Into Water
Peña Blanca sits inside the Fray Jorge Biosphere Reserve, an area of northern Chile where infrequent rainfall, climate variability, and pressure on traditional water sources have made every litre count. Many families draw what they can from shallow wells. When those run dry, they queue for cistern trucks – a lifeline that arrives on wheels rather than from the sky.
Against this backdrop, the idea of fog catchers took hold. The basic concept is simple. The execution, refined over years of trial and error, is anything but casual.
The technology traces back to the 1950s, when Chilean scientist, architect, and professor Carlos Espinosa Arancibia developed early fog catcher designs. Since 2006, communities in water‑stressed parts of Chile have been installing and adapting them. In Peña Blanca, that work accelerated with the help of the Un Alto en el Desierto Foundation and other partners.
FFA Explainer:
Fog catchers are vertical structures covered with fine mesh, usually installed on ridges where fog and wind are frequent. As fog passes through, tiny water droplets hit the mesh, combine, and form larger drops that trickle down into a gutter. Pipes then carry the harvested water to storage tanks or ponds.
In the Cerro Grande Ecological Reserve, dozens of these mesh panels now stand along the hillsides. Over the years, residents have tweaked everything: the height and angle of the panels, the type of netting, the spacing between posts, and the exact locations where fog and wind collide most often.
One of the main builders, 65‑year‑old Guido Rojas, has helped create dozens of square metres of catchment area over the last two decades. His work – and that of his neighbours – has turned a scientific concept into a living water system.
From Mist To Irrigation: How The System Works Day To Day
The science guiding Cerro Grande’s fog park is straightforward.
- Fog rolls in from the ocean and drapes over the Cerro Grande Ecological Reserve.
- High‑density meshes intercept the microdroplets that make up the fog.
- Droplets condense on the fibres, merge, and grow heavier.
- Gravity pulls the water down into gutters at the base of the mesh.
- Pipes or hoses channel the water into storage ponds.
- From there, hoses distribute it to irrigation plots and restoration areas.
Even on days with no rainfall, this steady trickle keeps crops alive and supports small production cycles. It is not a river – but in a thirsty landscape, it can be the difference between a dead field and a harvest.
Today, the Cerro Grande Reserve has 34 fog catchers covering 306 square metres of catchment area. That makes it the largest fog catchment park in Chile and one of the most important in Latin America, recognised both for its scale and for its consistency over time.
Together, those 306 square metres can collect up to 650,000 litres of water per year, mostly during spring, when fog and wind are strongest. What makes the system stand out is not just the volume but the range of uses.
The harvested water goes to:
- Irrigating crops for small‑scale farmers.
- Ecological restoration of native plant species in the reserve.
- Drinking water for people and animals.
Since the fog catchers were set up, around 7,000 people have visited the reserve. It has become an outdoor classroom for nature‑based solutions to water stress – a place where farmers, students, and policymakers can see fog turned into green shoots and full tanks.
FAO And Partners Help Scale Up The Fog Park
The system has not stood still. Through a project funded by the Global Environment Facility (GEF) and implemented by FAO with Chile’s Ministry of the Environment and the National Forestry Corporation, the fog catchment park has recently expanded.
This FAO‑GEF Land Restoration Project added 90 square metres of fog catchers to Cerro Grande, bolstering the community’s original work. The new panels are expected to produce more than 200,000 litres of water per year, especially during the critical spring and summer months when shortages bite hardest.
Watching over the newly installed panels on the hillside, Gustavo Carvajal, president of the Agricultural Community of Peña Blanca, sees a message that travels beyond their valley. He wants to keep supporting the community’s effort, he says, to show the world that practical, local action is possible even under harsh conditions.
FFA Explainer:
Nature-based solutions use natural processes and ecosystems – such as forests, wetlands, or, in this case, coastal fog patterns – to address challenges like drought, erosion, and climate change. They often rely on simple materials, local labour, and traditional knowledge, combined with modern science.
Why Fog Harvesting Matters For Dryland Farmers In Africa
For a communal farmer in Beitbridge or a smallholder in the Namib escarpment, the idea of catching water from the air might sound distant. Yet the conditions in Cerro Grande mirror realities across dryland Africa: erratic rainfall, groundwater under pressure, and heavy reliance on water trucking when everything else fails.
In parts of southern Africa, low clouds and mist regularly brush mountain slopes and coastal ranges. The eastern escarpment in South Africa, patches of Namibia’s Skeleton Coast, and Zimbabwe’s own Eastern Highlands all see recurring fog events.
Fog catchers do not replace dams or boreholes. But they can add a steady, climate‑resilient trickle to the water budget – especially in places where fog is frequent and land for reservoirs is scarce.
This sits neatly with African governments’ commitments under AU Agenda 2063 and the UN Sustainable Development Goals, particularly SDG 6 on clean water and SDG 13 on climate action. In Zimbabwe, it echoes the spirit of the National Development Strategy 1 (NDS1), which calls for climate‑smart water and agriculture investments.
Zimbabwe’s Fog And A New Source Of Water
In Zimbabwe’s Eastern Highlands – from Vumba to Nyanga – farmers know the feel of days when cloud and mist cling to the mountains. Trees drip, soil darkens, but the rain gauge barely moves. That hidden moisture is what Cerro Grande’s farmers are now catching.
Local innovators in Manicaland have begun experimenting with small mesh panels on homestead gardens, inspired partly by international examples like Chile. These early efforts, often built from shade cloth and timber poles, are still at trial stage, but they point to a practical question: if a 306‑square‑metre fog park in Chile can harvest 650,000 litres a year, what might be possible on a Nyanga ridge line where orographic clouds are frequent?
Such systems could serve:
- Market gardens run by women’s groups, supplying leafy vegetables into Mutare and surrounding growth points.
- Tree nurseries for indigenous woodlots and fruit trees, tying into land restoration programmes.
- Drinking points for goats and cattle, reducing pressure on shared boreholes.
Here, as in Chile, the crucial ingredients would be long‑term community commitment, support from local NGOs and universities, and the patience to refine designs over several seasons.
Design Lessons From Cerro Grande For African Communities
The Cerro Grande experience offers several practical lessons for communities in Africa considering fog harvesting.
- Low-Tech, High Knowledge: Fog catchers use simple materials – mesh, posts, gutters, pipes. The real value lies in knowing where to place them, at what height, and how to maintain them through windstorms and corrosion.
- Start Small, Learn Fast: Peña Blanca did not begin with 34 panels. Communities and partners added units gradually, testing mesh types, checking flow rates, and moving under‑performing structures to better sites.
- Multiple Uses Strengthen The Case: In Cerro Grande, harvested water is not just for irrigation; it feeds restoration plots and supplies people and animals. That diversity of uses spreads costs and builds support.
- Link To Landscape Restoration: Fog water in Chile is helping bring back native species. In African drylands, it could support replanting of indigenous trees and grasses, stabilising soils and improving local rainfall infiltration.
For governments and development partners, fog parks can be positioned as demonstration sites – much like Cerro Grande’s 7,000 visitors – where extension officers, engineers, and community leaders see the technology in action before adapting it to their own hills.
Women, Youth, And New Kinds Of Water Work
Fog harvesting is labour‑intensive in the right ways. It calls for builders to erect and maintain frames, technicians to monitor flows and quality, and guides to explain the system to visitors and trainees.
In Chile, people like builder Guido Rojas and community leader Gustavo Carvajal have become de facto experts. Their skills are transferable and, crucially, accessible. Unlike deep borehole drilling, fog catcher installation can be learned and taught locally.
For women and youth in African drylands, this opens a new category of work: climate and water technicians rooted in their communities. A school leaver in Chimanimani or Kariba could, with the right training, become a fog‑harvesting installer or a monitor for a local catchment association.
Tourism potential is another layer. Cerro Grande has become a destination for Chileans and foreign visitors interested in nature‑based solutions. A fog‑catcher park overlooking Nyanga, Mulanje, or the Drakensberg could attract similar interest, especially if linked with conservation areas and local craft markets.
Catching The Future, Drop By Drop
Back on the hills of Cerro Grande, the meshes stand still as the camanchaca rolls in. No pumps thrum, no diesel burns. The only movement is the slow thickening of droplets on the netting and the soft trickle of water into a gutter hidden by scrub.
Carvajal, watching the panels, sees both a local victory and a global message. Things can be done, he suggests – communities can answer water scarcity with practical ingenuity, given the right backing.
From Chile’s coastal fog to Zimbabwe’s mountain mists, that message lands close to home. Africa’s drylands will not be saved by any single technology. Yet each extra trickle matters. And as Cerro Grande shows, sometimes the missing water has been passing by our doorsteps all along, wrapped in cloud and waiting for a simple mesh to set it free.
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