In short: Fog catchers are nets that capture water from fog through condensation, without rain or grid infrastructure. In communities like Comas and Villa María del Triunfo, in Lima, they are providing access to drinking water where there was previously no option. Each Fluye bottle sold in Europe funds these projects. Today, March 27, 2026, is also the last day for Spain to transpose the EU Anti-Greenwashing Directive. The timing is an irony that tells its own story.
In Spain, Easter and rain have always gone together. It's a national meme. The suspended processions in Seville, the tourists with umbrellas in Malaga, the cold, damp end of March that seeps between the floats and candles. Water that ruins plans.
A two-hour flight from Lima, in Comas and Villa María del Triunfo, they haven't seen a drop for months.
It's not drought in the dramatic sense of the word. It's something more silent: the Peruvian coast has some of the densest fog on the planet, but it barely rains. The water is in the air, literally. What's missing is the infrastructure to capture it. And without grid infrastructure, without wells, without rain, what's left is buying water from tanker trucks at prices that families can't always afford.
Fog catchers are the answer to that. An answer that has existed for centuries and, in some ways, is older than modern plumbing.
What is a fog catcher and how does it work?
A fog catcher is a mesh stretched between two poles, oriented perpendicular to the prevailing wind. When fog passes through the mesh, the tiny suspended water droplets collide with the threads and condense. The droplets join together, become heavier, and fall by gravity into a lower channel that directs them to a reservoir.
The physical principle is the same one that makes windowpanes wet on foggy mornings. The difference is that a forty-square-meter mesh, properly installed, can capture between two hundred and four hundred liters per day in areas with dense fog. In some cases, on the most exposed hills of Lima, catches exceed five hundred liters per day per installation.
The most common material is a high-density polypropylene mesh, similar to Raschel fabric. The mesh density is critical: too open allows water to pass through without being captured, too closed blocks airflow. Orientation also matters. A mesh perpendicular to the wind captures up to four times more than one poorly oriented.
It doesn't need electricity. It doesn't need a distribution network. It doesn't need specialized maintenance. The materials cost a fraction of what it costs to install a pipeline in hard-to-reach areas. And fog, on the Peruvian coast, is a constant resource for months without rain.
Why the Lima coast has fog but no rain
The geographical explanation is the Humboldt Current. This cold water current that flows up the Pacific coast from Antarctica cools the air over the sea, which generates condensation and fog, but prevents that condensation from rising high enough to turn into rain. The humid air stays low, clinging to the coast, but does not ascend to precipitate.
The result is a coastal strip that can have thick fog for months, with overcast skies and a feeling of humidity, but with annual rainfall that in some areas does not exceed fifteen millimeters. To put it in perspective: Madrid receives an average of about four hundred millimeters of rain per year. The Lima coast, less than four percent of that.
This fog has its own name in Peru. It's called garúa, and it appears mainly between June and November, when the cold current is most intense. During these months, the hills surrounding Lima fill with a fog that leaves everything damp but does not fall as rain. Fog catchers are designed precisely for this type of humidity.
The communities where it works
Comas and Villa María del Triunfo are two districts of Lima that grew rapidly and chaotically, climbing the hills surrounding the city. Many of these settlements reached areas where the drinking water network never arrived, because installing infrastructure on rocky slopes at six or seven hundred meters of altitude has a cost that municipalities have not been able or willing to bear.
Families in these areas depended on tanker trucks, which arrive at irregular times and charge by the liter. Truck water is expensive for low incomes, and its quality is not always guaranteed. For cooking, for drinking, for children, water was a variable and sometimes unpredictable expense.
Fog catchers change the equation. They don't eliminate the need for tanker trucks, but they reduce it. A well-installed system can cover the water needs for drinking and cooking of several families during the garúa months. In some cases, the surplus is used for family gardens that add dietary variety.
More context on the global dimension of this problem and how it relates to access to drinking water can be found in the article on access to drinking water as an invisible problem.
How every Fluye bottle funds these projects
Fluye works in partnership with Los Sin Agua, an organization that installs and maintains fog catchers on the hills of Lima. Each bottle sold in Europe funds a part of that work: installation of nets, maintenance of the capture systems, training of communities to manage the facilities autonomously.
The impact of each sale translates into liters of water funded. Not in trees planted with a methodology that no one can verify. Not in tons of CO₂ offset in a forest that exists in a PDF. In liters of water, in a specific address, in a community with a name and geographical coordinates.
Fluye's impact dashboard shows this data in real time. Georeferenced photos of the installations, quarterly reports of water captured, tracking of active projects. The impact is auditable because it is documented. This is unusual in the sector.
You can see the current status of the projects and the accumulated impact on Fluye's impact page.
March 27, 2026, and what changes today in Europe
Today is the official deadline for Spain to transpose the European Union's Anti-Greenwashing Directive. From now on, companies operating in the European market cannot communicate environmental benefits that they cannot prove with verifiable data and standardized methodology. "Sustainability promises" without evidence cease to be legal.
Greenwashing has been the standard suit of sustainability marketing for twenty years. Green packaging, vague environmental claims, cardboard certifications. While Europe legislates empty promises, here there is real water in a photo with geolocation.
Fluye does not have the problem that the Directive tries to solve. Impact is not a marketing claim. It is a number with coordinates. The photos of the fog catchers on the hills of Comas are not in the investor presentation deck: they are on the dashboard that anyone can see.
It's not a special merit. It's how it should always work. The Directive simply makes it mandatory for everyone else.
In Spain, meanwhile, next week it will rain on the processions. In Villa María del Triunfo, that rain that ruins plans here has another value. A much more literal one.
Written by the Fluye Bottle team