Collecting water from fog is not a new idea, but it is becoming increasingly popular as the world deals with desertification and raging fires brought by a warming climate. In Spain’s Canary Islands, the EU-backed Life Nieblas project (niebla is Spanish for fog) is using fog collectors to restore the islands’ laurel forests, which themselves naturally collect fog water. Restoring laurisilva also can help replenish the Canaries’ aquifers.
Transforming an area degraded by centuries of logging and massive extraction of water from aquifers, as well as a devastating fire, into a model of environmental recovery, matters because 90% of Gran Canaria’s land is under great water stress due to reduced rainfall. It is the most ambitious LIFE project ever carried out in Gran Canaria, with a budget of more than two million Euros and a four year time span.
It aims to recover the forests and aquifers of 35 hectares in two areas, Barranco de la Virgen and Selva de Doramas, and then expand to the Mediterranean basin and Portugal. Laurisilva is sub-tropical rainforest populated by evergreen species, not necessarily the laurels found in parks and gardens.
The aim is to capture 215,000 litres of fog and dew water a year to repopulate 35 hectares (86 acres) with 20,000 laurel trees in the Doramas Forest. The reforestation will be carried out with native species typical of laurisilva, including the candleberry myrtle (Myrica faya), strawberry tree (Arbutus unedo) and barbusano (Apollonias barbujana).
Individual fog catchers are key to the intervention, as the goal is for the new laurel forests to survive on their own without irrigation for 18 months, by which time the vegetation itself will capture the fog it needs, says CREAF.
The new generation forest will bring springs back to life and favour the recovery of aquifers, which are essential for supplying farms, livestock and population without the need to drill wells, because the water captured by the forest can infiltrate into the ground five times greater than that of rain. “With this initiative, we are tackling reforestation in a more viable and effective way, acting in areas that are particularly vulnerable to climate change and desertification,” says head scientist Vicenç Carabassa, who works for the Centre for Ecological Research and Forestry Applications (CREAF), a public research institute at the Autonomous University of Barcelona.
The artificial fog collectors – plastic sheets placed in the path of the wind – collect water droplets as the wind blows fog through the mesh. The droplets fall into containers below. “The system allows saplings to flourish until they are mature enough to capture water themselves,” says Carabassa.
The researchers are also using the “cocoon”, a biodegradable, doughnut-shaped container that surrounds the hole where a seedling is planted and can hold 25 litres of water. Developed by the Dutch firm Land Life, it provides water and shelter for the seedling, at least during its first year. It is filled manually at first, but then recharged by rainfall or in the Canaries and Portugal, with water from fog collectors. Testing in Spain, Italy and Greece showed that compared with conventional planting systems, cocoons increased the rate of seedling survival, especially under dry growing conditions.
It is not just forest restoration in the Canary Islands that is using fog collectors. Since 2018, award-winning farmers Jonay González Pérez and Sara Rodríguez Dorta have relied on their homemade fog collecting system to water 3.7 acres of farmland – which includes lemon and plum trees, artichoke plants, and 50 chickens – during the summer months, the Christian Science Monitor reported recently.
Their 435-yard-long wall of collectors – vertical U-shaped nets cemented into the ground by metal poles – can harvest 475 gallons of water. The captured droplets fall flow through 220 yards of black tubing that leads to a 95,000-gallon storage tank that resembles a giant waterbed. They built the system themselves over a year, with government subsidies, after they won a local award for the best initiative in rural farming.
Sources:
Fog can give a second chance to desertified land. CREAF, Jan. 27, 2021
Farming fog for water? Canary Islands tap a new reservoir. Christian Science Monitor, Nov. 9, 2022
The Cocoon system improves success rates when reforesting degraded land. CREAF, Feb. 24, 2020
Life Nieblas website.