They Catch Clouds in Nets to Bring Water to the Moroccan Desert

High in the Anti-Atlas Mountains of Southwest Morocco, the land is a study in aridity. In the region of Aït Baâmrane, rainfall is a rare blessing, often totalling less than 13 centimetres a year. For generations, the Amazigh (Berber) communities here have survived by digging deep wells that often run dry or wait for water trucks that many cannot afford. But for six months of the year, a strange phenomenon occurs: a thick, white blanket of fog rolls in from the Atlantic Ocean, engulfing the peaks of Mount Boutmezguida. While most saw this as a navigational hazard, Dr Aissa Derhem and Dr Jamila Bargach saw it as a river in the sky. Through their NGO, Dar Si Hmad, they have built the world’s largest fog-harvesting system, turning mist into a sustainable source of life for over 1,000 people.

The concept of fog harvesting is an ancient practice seen in various desert cultures, but Dar Si Hmad has brought it into the 21st century with scientific precision. The project, by situating its infrastructure at an altitude of 1,225 meters, uses "CloudFisher" technology, a revolutionary net design by German engineer Peter Trautwein. These nets are not simple meshes; they are high-tension, honeycomb-style structures capable of withstanding the mountain’s violent winds, which can exceed 100 km/h. When the fog passes through these fine nets, tiny water droplets snag on the fibres, coalesce, and trickle down into a gutter that leads to a complex distribution network.

The physics of the harvest is elegant. A single net can harvest up to 600 litres of water on a productive day. The total system currently utilises 1,700 square meters of netting, yielding an annual average of over 6,300 litres of fresh water daily. This water is then piped through 6 kilometres of gravity-flow lines to 16 different villages. Crucially, the system is 100% passive; it requires no external energy to collect the water, making it one of the greenest water technologies in the world. Once collected, the water is pumped through a solar-powered UV filtration station and mineralised to meet World Health Organisation (WHO) standards for drinking water.

The project has had a profound social impact, particularly on the lives of women and girls. In Amazigh culture, women were traditionally the "water guardians," but this role came with the heavy burden of spending up to four hours a day fetching water from distant, often contaminated wells. With the introduction of fog-harvesting, clean water is now piped directly into their homes. To ensure the women remained empowered, Dar Si Hmad introduced a mobile monitoring system. Women now use SMS technology and tablets to monitor water levels, manage household supply, and report infrastructure issues, transitioning from physical labor to technical resource management.

Dar Si Hmad’s vision extends beyond the tap. In 2018, the heirs of a local farmer bequeathed a piece of abandoned, desiccated land to the foundation. Dar Si Hmad transformed this rocky terrain into the "Agdal Ibrahim Id Aachour" educational farm, an oasis irrigated entirely by excess fog water. The farm serves as a didactic site for agroecology, training local youth and farmers in sustainable practices that respect the earth. It is also home to "Tin’Amoud," the region’s first seed library, which safeguards local heirloom seeds that are adaptable to dry conditions.

The project has faced significant cultural and environmental challenges. In the early stages, some villagers were sceptical that "drinking the fog" was even possible. The team had to engage in a slow process of community building and institutional adaptability to overcome social resistance. Environmentally, the extreme winds of the Anti-Atlas initially damaged the pilot nets, forcing a shift to the more robust CloudFisher design. Today, the project is a global model for climate adaptation, recognised with awards from the United Nations and the Roy Award at Harvard.

For Jamila Bargach, the project is a series of "connected loops" involving water, education, and culture. During the COVID-19 pandemic, the system proved its resilience, ensuring that remote communities remained hydrated and safe while cities faced supply disruptions. As desertification threatens many parts of North Africa, Dar Si Hmad’s CloudFishers stand as a beacon of hope. They have proven that by combining scientific ingenuity with indigenous respect for nature, it is possible to harvest life from the very air we breathe.

Dar Si Hmad: Technical & Impact Specifications