How the Upper Tana Water Fund has Restored Ecosystem and Strengthened Nairobi’s Water Sources in a Decade
A decade of sustained investment in the Upper Tana watershed has played a key role in strengthening Nairobi’s water security. The initiative has helped ensure cleaner and more reliable water for millions of residents. Through a ten-year partnership involving government agencies, utilities, businesses, and farming communities, the Upper Tana-Nairobi Water Fund Trust has worked to reduce sediment flowing into rivers, restore degraded landscapes, and improve dry-season river flows through nature-based solutions.
These efforts have helped the city cope with increasing pressure from climate variability and rising water demand, highlighting the importance of protecting water sources as critical infrastructure for a resilient and rapidly growing Nairobi.
According to the Upper Tana-Nairobi Water Fund Trust, which promotes long-term management of water sources through nature-based solutions, these efforts have significantly strengthened the water supply for Nairobi. The initiative has helped reduce sedimentation, improve water quality, stabilize river flows, and enhance the efficiency of water treatment systems. As a result, it now delivers more than 27 million litres of additional water each day during the dry season.
Speaking during the tenth anniversary celebration in Nairobi, the Principal Secretary for Environment and Climate Change, Festus K. Ng’eno, described the Upper Tana-Nairobi Water Fund Trust as one of Kenya’s most successful examples of a public–private partnership in watershed restoration. He noted that the initiative has brought together government agencies, utilities, local communities, and private sector players to collectively safeguard critical water sources.
“As pressures on Kenya’s water towers increase due to population growth, land use change, and climate impacts, sustained investment is essential. The Water Fund model delivers strong returns through reduced water treatment costs, improved water quality, and long-term ecosystem resilience. The Ministry calls on development partners, private sector actors, climate funds, and local philanthropies to scale investment and replicate this model across Kenya’s water towers,” said Dr. Eng. Festus K. Ng’eno, CBS, Principal Secretary, State Department for Environment and Climate Change, Ministry of Environment, Climate Change and Forestry.
The Upper Tana-Nairobi Water Fund Trust’s Trustee President, Eddy Njoroge, emphasised the importance of upstream investment and strong partnerships. “The program’s success over the past decade demonstrates the value of addressing water security challenges at their source while building strong partnerships across sectors. Our biggest lesson from the last ten years has been that it is more cost-effective to address these challenges upstream. We look forward to another celebration in ten years as we continue working with farmers, government, and stakeholders to conserve the Upper Tana watershed using Nature-Based Solutions to mitigate the impacts of climate change, improve farmers’ livelihoods, and secure a consistent supply of clean water for Nairobi.”
Over 470,000 acres of farmland and forest, along with 980 kilometres of rivers, are now under improved sustainable management through the efforts of the Upper Tana-Nairobi Water Fund Trust. More than 260,000 farmers have embraced climate-resilient land management practices, including the installation of 17,000 water pans that collectively harvest over 2 billion litres of rainwater each year. In the past decade, the initiative has also facilitated the planting of 5.9 million trees, created more than 22,000 green jobs, and helped farmers generate an additional 118 million US dollars in income through fruit, nut, and livestock feed value chains.
Water supply risks for both the private sector and domestic users in Nairobi have significantly declined following a 41 percent reduction in water turbidity. This improvement has also led to savings of approximately 1.2 million US dollars in water treatment costs. The Upper Tana River Basin, which forms the upper section of the Tana River, remains the primary water source for the city. It supplies about 95 percent of the water used by Nairobi’s 4.8 million residents and also supports an additional five million people living within the basin.
The Nature Conservancy established the Upper Tana-Nairobi Water Fund Trust in 2015 as Africa’s first water fund initiative aimed at securing water resources at their source. Since then, the programme has evolved into an independent, registered public charitable trust guided by strong governance structures, science-based decision-making, and collaborative investment.
The water fund model was first pioneered in Quito in 2000. Since then, it has been replicated in more than 30 cities globally, including 16 across Africa.
In Kenya, several initiatives have adopted this approach, including the Upper Tana-Nairobi Water Fund Trust, the Eldoret-Iten Water Fund, the River Yala-Nyando Water Fund, the Upper Tana Mid-Galana Water Fund, and the Jumuiya Water Fund. These initiatives aim to protect and sustainably manage critical water sources through collaborative partnerships and nature-based solutions.
“The Upper Tana shows that when you protect water at the source, the impact is immediate and measurable. Cleaner water for Nairobi, stronger dry-season flows, and better incomes for the farmers who make this work possible. After ten years, the results speak for themselves. With sediment down by more than 40 percent, more than 260,000 farmers improving their land, and billions of litres of water harvested upstream each year, this model is delivering what growing African cities needs reliable, affordable water in a changing climate,” said Ademola Ajagbe, Regional Managing Director, Africa, The Nature Conservancy (TNC).
During the anniversary event, partners emphasized the need for more sustainable financing, stronger private sector participation, and deeper community engagement, especially with young individuals, to ensure the water fund model continues delivering long- term benefits and can be replicated in other cities across Kenya.
