Harvesting fog in western Yemen


elder and a fog haversting panel
An elder local monitors the performance of the fog harvesting unit used in the pilot project in western Yemen. Photo: UNDP Yemen

“God has given us the fog to quench our thirst,” says Am Ali, mother of six, who lives in Manakha, Yemen.

Manakha is a rural district in the mountains, where residents live in scattered settlements across the remote highlands. Their only natural source of water is rainfall. Water is scarce at the best of times, and with climate change making rainfall more unpredictable, that scarcity is reaching a crisis point.

In the Manakha Mount area, water availability from rain sometimes doesn’t even reach 50 m³ per capita per year. Women and girls spend much of their days fetching water. The open community water reservoirs contain stagnant, poor-quality water and poor water quality. Water-borne diseases are common.

Highlights

  • 1,563 people have benefitted from the project so far, with approximately 200 units installed in Manakha and another 15 in nearby Raymah Governorate.
  • A coffee tree nursery has a capacity of propagating more than 5,000 seedlings per year, benefitting some 150 farmers and agribusinesses across 20 villages.
  • Local communities are using locally-sourced bamboo to build roofs for cisterns. More than 50 households now use bamboo-roofed cisterns.

Innovative local actions were urgently needed to address this crisis. So UNDP, in partnership with the National Foundation for Watershed Management and Services (and funded by the Water Governance Project for Arab States) has been working to help communities in Manakha take advantage of a surprising resource: fog.

While rainfall is increasingly scarce, fog is ever present. Heavy fog usually arrives every afternoon and can remain until the early morning hours. Residents in the area have long used fog to help cultivate coffee: Coffee trees are planted in terraces throughout the region, and it traditional to encircle these trees’ bases with stones. The fog condenses on the stones and then runs down into the soil. A similar method could be used to harvest water to improve agricultural outcomes and increase household water supplies.

The project designed and implemented complementary activities, holding demonstrations on how to use fog harvesters, installing the water harvesters, and establishing a coffee tree nursery.

The fog-harvesting units are 3x2 meter mesh screens that condense enough fog to provide drinking water for a family of seven. Local communities are now benefiting from the increase in drinkable water and women and children are no longer required to travel hours to collect water during the dry months. Takiah Bent Ahmed, 35, says that her daughter and sons use to travel three hours to fetch water.

“Now, I will be able to release my children from this tedious task,” she says. “We now have more water in the house and I don’t worry much about my children’s health.”

The devices have collected up to 40 litres of water a day. Community members have been actively improving the systems and have found ways to make the systems cheaper and easier by introducing and testing several new alteration and measures to the system. Such innovations cost less than US$15 and will help to disseminate the technology throughout Yemen.

Some 1,563 people have benefitted from the project so far, with approximately 200 units installed in Manakha and another 15 in nearby Raymah Governorate. The nursery that was planted has a capacity of propagating more than 5,000 coffee tree seedlings per year, benefitting some 150 farmers and agribusinesses across 20 villages.

The project has also piloted other interventions, including using gravel filters to purify water and improving water management practices by constructing rainwater diverting structures and flooding and soil erosion control measures. Local communities are also now using locally-sourced bamboo to build roofs for cisterns, a cost-effective method that has gained strong buy-in because local communities developed it. More than 50 households now use bamboo-roofed cisterns.

The pilot project concluded last December and follow-up interventions are underway, including a $6 million rainwater-harvesting project. The water harvesting project will revive traditional methods and introduce new techniques for water harvesting in five governorates. The fog water harvesting has been piloted successfully and will be scaled up for greater coverage and impacts elsewhere in Yemen.