Fog collectors net scarce water in Kenya, but face a cloudy future
With a thirsty and impatient boy waiting nearby, Joseph Kipalian draws water from a tank and pours it into the boy's bucket. The school-yard water tank is fed from an unusual source: the air.
Ilmasin primary school, in the Ngong hills south of Nairobi, is outfitted with fog collectors, contraptions of huge metal and wooden poles that hold mesh-patterned nets. These trap fog droplets, which trickle into holding tanks.
The project, set up by the Jomo Kenyatta University of Agriculture and Technology, aims to test the viability of harvesting fog to help provide a safe and reliable source of water in water-scarce areas. But the results have been mixed, not least because keeping the collectors up and working has proved a challenge.
Bancy Mati, a soil and water engineering professor at the university, says fog collection is one of the cheapest and most environmentally friendly ways of collecting clean water.
She launched the Kenya collector after a similar project, set up by a German nongovernmental organisation, ran successfully in Tanzania. The region around the Ngong hills is a great place to collect water, she said, since it sees fog both in the early morning and throughout the night.
The region is semi-arid and has perpetual problems with water shortages, she said.
Fog collectors, if built at scale, could help unlock the economic potential of dry but fertile areas like Ilmasin by providing water for irrigation and livestock as well as for families, Mati said.
She hopes the collectors could be used in a range of places across Kenya, particularly Marsabit County in northern Kenya, another semi-arid region with plenty of fog.
Gone with the wind
But while the technology has been used successfully in a range of areas of the world, from Chile to Yemen, keeping the fog-catching arrays up and working in the long term has proved a challenge in many places.
In Ilmasin, the collectors were installed in 2014 and for a time produced 60 litres of clean water a day - about half of what the school of 340 students needs to operate each day.
But high winds in 2015 destroyed part of the system and wear and tear on the nets and poles is also taking a toll. Production is now just 20 to 30 litres of water a day, said Kipalian, who operates the system.
That has led to rationing of water, and Kipalian says he worries women and girls will once again have to travel long distances in search of clean drinking water, or spend money they don't have buying water.
When the fog collector was in full operation, school girls - spared the task of walking to collect water - had more time for studies, he said, and water was often available for livestock as well.
But Mati said she has yet to find continuing funding to sustain the fog collection system, as nets - imported from Chile - and iron poles are expensive to replace, and timber poles have not proved durable enough.
She hopes the government might exempt the nets from import taxes to lower their price and make them more widely accessible. She is also looking into whether nets can be manufactured locally, she said, with an ultimate aim of installing one fog collection system per home in Ilmasin.
John Simel, the Ilmasin school's headmaster, said he feared the school might face health issues if the system fails and the school has too little clean drinking water. The area at times receives little or no rain over a six-month period, he said.
The fog collectors, he said, have also played a role in helping the children better understand environmental issues and the importance of natural resources to local lives and jobs.