The misty clouds floating over the Ngong' hills, a rocky ridge on the fringes of Nairobi city, have long provided the Maasai tribal community with dew that keeps the grass sprouting for their animals.
Lately, however, Lucy Lotuno and a few of her Maasai peers have learned that the fog also can provide fresh drinking water right on their doorsteps.
The grandmother of nine happily showed off a recently installed fog harvesting plant in Olteyani village, Kajiado County, an arid area to the southwest of Kenya's capital.
The plant, which serves a few households, works by capturing fog in nets and draining the collected droplets of clean water into barrels below. Depending on the density of the fog, the unit can provide enough water for 20 to 40 people daily.
"I am happy because I have clean water near my home instead of walking long distances to look for it," beamed the 45-year-old. "I am able to rest and do more domestic chores than before."
Like many other women in semi-arid parts of Kenya, the search for water is a daily grind that leaves them weary from walking miles to the nearest water point, often shared with livestock and wildlife.
According to Lotuno, fetching water from distant sources has been part of her life since she was growing up.
That is why she is so vigilant when it comes to protecting the plant, located just a few metres from her homestead. Curious visitors are confronted by the suspicious grandmother, who demands to know why they have stopped by.
Stretched between two posts planted in the ground, a layer of mesh netting traps tiny water droplets which collect into a supply gutter before draining into a barrel. The water is immediately ready for consumption, according to Bancy Mati, a professor at Jomo Kenyatta University of Agriculture and Technology.
"Fog harvesting is a sustainable way of reducing the pressure on water resources but it remains widely untapped," she said.
She is the director of the university's Water Research and Resource Centre and one of the founders of the fog harvesting technology in Kenya, in collaboration with the Kenya Meteorological Department and PedWorld, a German non-governmental organisation that contributed trap nets.
Her university helped research the viability of fog harvesting at Olteyani, in conjunction with the rural community, she said.
Mati said fog harvesting technology is in use in Germany, Chile and Tanzania. A single fog collector can tap between 400 litres and 1,000 litres of water per day, depending on the size and design of the mesh and the atmospheric fog density, she added.
The Olteyani plant is the first one in Kenya, funded by the Kenya Meteorological Department (KMD). But the plant's backers hope to raise funds to establish more and larger plants over the next five years for rural Kenyans, Mati said. According to KMD, the Olteyani fog collector cost about $300.
Fog occurs when air is cooled to a point at which it can no longer retain the water vapour it contains, forming ground-level clouds.
It is common in low-lying plains dotted with isolated hills, and low mountains which trap and hold clouds or force moisture-laden winds into high altitudes, according to a recent Master Plan for the Conservation and Sustainable Management of Water Catchment Areas in Kenya, produced by the government and the UN Environment Programme (UNEP).
"Fog and mist occur mainly at night and early in the morning," explained Peter Ambeje, deputy director of the KMD. "It is heaviest in the months of May to September."
REDUCING PRESSURE ON SUPPLIES
Its abundance in places like Olteyani and other parts of the country might mean better living conditions for Kenyans like Lotuno. If fog harvesting gathers momentum as experts hope, it could reduce pressure on the country's decreasing water resources, experts say.
The United Nations categorises Kenya as a water-scarce country, while studies by agencies such as UNEP say the problem has worsened in recent decades due to climate change.
"Innovations that scientifically enable the generation of fresh water are what we are aiming for in the new conservation masterplan," said Kenya's environment secretary, Alice Kaundia. "The government is keen to support the fog harvesting technology" by allocating research funds to the country's meteorological department, she said.
Studies link Kenya's widening poverty gap to overexploitation of natural resources, including water.
"Most of the poverty taking root in Kenya is due to unsustainable use of natural resources," said Achim Steiner, executive director of the United Nations Environment Programme, during a press conference in Nairobi in late July. He called for policy makers to balance a push for development with the need to provide basic services in the country in order "to keep the country on a peaceful trail."
The United Nations Environment Programme has highlighted the increasing pressure on Kenya's wetlands, despite repeated warnings about the ecosystem's fragility.
The 2013 UNEP Kenya Wetlands Atlas maps an emerging pattern where ecosystems flanking cities and other urban areas are coming under stress due to new settlements, as populations move from rural areas in search of livelihoods.
According to the report, more than 75 percent of Kenya's population is concentrated in areas with high economic potential. Those areas represent just 20 percent of Kenya's land.
"These tend to be forest areas and sources of Kenya's major river basins, resulting in further pressure on natural resources," said the Atlas. "This causes loss of wetlands, increased demand for pasture, clearing of vegetation, decrease in agriculture productivity and increase in water extraction rates."
Kagondu Njagi is an environmental writer based in Nairobi.