Catching fog for water above Lima's hillside settlements
Abel Cruz and his movement put up nylon mesh nets on the hills around Lima to catch coastal fog, giving water-poor settlements a small, local supply.
The small thing
By his own account, Cruz noticed that the plastic mesh fencing around his home on the edge of Lima was collecting droplets of moisture from the fog. He began experimenting with mesh as a way of catching water.
The problem
Lima sits in a desert and receives almost no rain. Around a million residents, many in hillside settlements, have no piped water and buy it from tanker trucks at prices well above what connected households pay. Reporting in 2012 noted that the water utility did not expect to reach some of these hills soon.
Why Abel started
After years of protesting for fairer access to city water, Cruz turned to building a supply communities could make themselves; he told Guernica they had never stopped to think about making their own. He grew up hauling water uphill near Cusco, an experience he links to his work.
What they did
Cruz took part in a fog-water pilot when the German group Alimón e.V. came to Peru in 2006, helping with pilot studies, choosing sites and training residents to build the nets. Each net is a sheet of nylon mesh about 6 by 4 metres, strung on hillsides where fog drifts in from the Pacific; droplets collect on the mesh and run into tanks.
In Cerro Nueva Esperanza, on Lima's outskirts, Al Jazeera reported in 2012 that 20 nets fed a system of plastic tubes and 20 tanks. Cruz secured a USAID grant to build more nets and says he has since installed many more.
What changed
According to Al Jazeera (2012), each net in Cerro Nueva Esperanza could condense about 90 litres a day, up to about 3,000 litres in total on good days, and more than 70 families received water in their taps; one resident used it to grow a garden. In a 2024 interview with Orato, Cruz said he had installed around 6,000 fog catchers, a figure that has not been independently verified. Both sources note the water is used mainly for irrigation and cleaning rather than drinking.
What they learned
Cruz has said the nets work best as a supplement, and that the water still needs treatment before drinking; he is researching natural purification methods. He also describes patience: his first trial produced nothing for eight days.
“this could become the pilot programme to secure water for thousands of people”Abel Cruz, as quoted by Al Jazeera
Copy this idea
Practical guidance written by our editors from the sources below. Adapt it to your place, and check local rules and safety first.
- Problem addressed
- Households in dry, foggy places with little or no piped water.
- What to do
- Mesh nets on frames placed on slopes where fog regularly passes, with gutters and pipes leading to storage tanks.
- Materials and resources
- Fine mesh (such as nylon or polypropylene), poles, cables, gutters, pipes, covered tanks.
- Approximate cost
- Low
- Skills
- Basic construction; site selection with local knowledge of fog patterns; water-quality testing.
- Time
- Weeks to install; a season of monitoring to see yield.
- People needed
- A small team plus households who will maintain it.
- Difficulty
- Moderate
- Risks and limitations
- Water may be contaminated; use for irrigation or cleaning unless it is tested and treated. Steep sites can be dangerous to work on; secure frames against wind.
- How to adapt it
- Only suitable where fog is frequent; check with local water or meteorological services first.
- Lessons learned
- Measure yield before scaling up, and treat fog water as a supplement rather than a full supply.
Why it matters
Fog nets cannot supply a city of millions, and reporters have stressed they meet only a small share of need. But they show how a low-tech, locally built device can ease daily water costs for households left off the network, and how a community can make use of a resource that is otherwise ignored.
What didn't work
The water is not yet safe to drink without treatment. Output depends heavily on fog density and season. Journalists have noted that the scale is far too small to meet Lima's water needs, which still require public investment.
Editor's note
Started year reflects Guernica's report that Cruz joined a fog-water pilot in 2006; in a 2024 first-person account (Orato) he says he founded his movement in 2002. Still active as of that 2024 report.
Sources: how do we know?
Evidence level: Documented. Supported by reliable published sources such as UN agencies, award bodies and reputable journalism. Not yet independently re-verified by our editors. What the person says and what independent sources establish are attributed separately in the text.
- reputable journalism
'Cloud catchers' aid parched Peruvians — Al Jazeera, 27 August 2012Supports: Cruz leads Peruvians Without Water; 20 nets in Cerro Nueva Esperanza, about 90 litres per net per day, up to 3,000 litres total, more than 70 families served; water may not be drinkable; quote. - reputable journalism
Catching Fog in Lima — Aleszu Bajak, Guernica, 8 January 2013Supports: Cruz joined the Alimón e.V. pilot in 2006, trained residents, secured USAID funding; around a million Limeños lack running water; turned from protest to building supply. - organisational
Cusco native develops fog catchers, bringing water and hope to Peru's driest communities — Orato World Media, 3 September 2024Supports: Cruz's own first-person account: childhood near Cusco, mesh-fence observation, movement founded 2002, about 6,000 fog catchers claimed, water used for irrigation and cleaning, current status (2024).