Eritrea – Nefasit und Arborobue

Nefasit and Arborobue

Initial situation

A country like Eritrea, which constantly struggles with water shortages, is open to anything that promises to improve the water supply. The idea of collecting clean water from fog was not known in Eritrea, but it seemed realistic when our test collectors in the highlands of the Maakel region delivered surprisingly good results between 2005 and 2006. The government has recognized the great potential of this simple technology. It is convinced that this method can significantly improve the drinking water supply in the entire Maakel region and in the neighboring fog-rich areas in Zoba Debub. In addition, the Ministry of the Environment also sees it as a good opportunity to successfully implement reforestation projects. So far, only 30 percent of young plants survive the drought stress in Eritrea.

How to get water from fog

The principle is quite simple: there are regions on earth where, due to the geographical situation, there is no rain for many months of the year, but there is a lot of fog. This is also the case in Eritrea, where air warmed in the interior of the country rises and draws in the moist air formed over the Red Sea. From October to March, dense fog then forms over the Maakel region, which lies between 1,700 and 2,500 meters. The fog nets must be set up exactly at a 90-degree angle to the wind so that they can extract up to 50 percent of the moisture from the fog. The tiny dewdrops collect on the mesh of countless triangles and combine to form ever larger drops. The largest drop forms at the bottom point of the triangle and drips into the collecting channel. The water collected in this way is fed through pipes into a sedimentation tank and from there into the 3,000-liter water tanks.

Planning and implementation

Two villages, both situated at an altitude of over 2,000 meters, were selected to set up the first 20 large fog collectors: Nefasit and Arborobue. In January 2007, three employees of our project partner FogQuest traveled from Chile and Canada to Eritrea to set up 10 fog nets for the school in Nefasit during their eight-week stay. During this time, Vision Eritrea, our local partner at the time, became familiar with the technology and was able to set up 10 more collectors for the village of Arborobue in the following months.

Before the two systems were handed over to the municipal administrations on August 7 and 8, 2007, the pipes still had to be laid, the tanks set up and the taps with 8 faucets each had to be built and fenced in. Each village has set up a water committee that is responsible for maintaining the facilities.

Result

The twenty 36-square-meter fog catchers yield about 3,400 liters of drinking water per day and net. The 800,000 liters collected during the eight-month rainy and fog season supply 1,100 children at the Debre Bizen Elementary, Junior and Senior Schools in Nefasit, as well as 120 families and the school in the village of Arborobue with clean water.

Changes and improvements

In December 2008, changes and improvements were made to the fog collectors in Arborobue to adapt them to the local conditions, in particular the wind speeds. They now serve as a showcase project for the whole of Eritrea.

In addition, consideration is being given to reducing the production costs for the collectors. The necessary materials are to be procured in the country. The expensive, imported steel tubes to which the nets are attached are to be replaced, for example, by wooden posts made of local eucalyptus.

It has been agreed with the mayor of the state capital Asmara, who is also the governor of the fog-laden Maakel region, that in future his state government will be responsible for maintaining the facilities in Arborobue. We will plan and implement further fog projects with them.

Outlook

Several hundred thousand people could be supplied with clean water in this way in the 500-kilometer-long and up to 2,500-meter-high highlands. Women and girls would no longer have to make the often arduous journey into the valleys to fetch water for their families.