Kenya's Tana River Conservation Secures Nairobi's Water Supply Amid Climate Change
Protecting the River Tana in the Meru National Park is now securing the water supply to Kenya's capital, Nairobi. By conserving the watershed and improving farming methods, this initiative is safeguarding water resources and livelihoods in the face of a changing climate.
Transforming Farming Practices for Water Security
In 2017, David Nyoro became one of the first farmers to partner with Africa's inaugural water fund, aimed at conserving the watershed of Kenya's largest river. He received 180 high-value avocado seedlings, which marked a shift from his previous reliance on annual crops that left his five-acre land bare, exacerbating soil erosion and river sedimentation. "We used to lose a lot of topsoil to the river. Such loss of soil nutrients and poor farming practices meant we had less farm produce," Nyoro explains.
The avocado seedlings enabled him to increase his farm income to nearly 2 million Kenyan shillings, with each mature tree yielding 70 kilograms annually. By introducing cover crops, he improved soil health and reduced erosion, contributing to cleaner water downstream. "Improving farming methods and conserving the watershed has helped me to feed and educate my six children, while those in Nairobi and others downstream can enjoy more clean water from these rivers," he adds.
Impact of the Upper Tana-Nairobi Water Fund Trust
Over the past decade, the Upper Tana-Nairobi water fund trust has delivered more than 27 million liters of additional dry-season water daily to Nairobi, according to its developers. The project has achieved a 41% decline in water turbidity, saving urban authorities £900,000 in treatment costs and demonstrating how nature-based solutions can protect urban water systems from climate variability.
Established in 2015 by the Nature Conservancy, the fund aims to secure the Tana River by reducing sediment flow and restoring degraded landscapes. The river supplies 95% of water for Nairobi's 4.8 million residents and 5 million others in the basin, while its dams contribute over 50% of Kenya's hydroelectric capacity.
- More than 470,000 acres of farms and forests are under sustainable management.
- Over 260,000 farmers have adopted climate-resilient practices, including 17,000 water pans that collect 2 billion liters of rainwater annually.
- The fund has supported the planting of 5.9 million trees, created 22,000 green jobs, and generated $118 million in additional farmer income through value chains.
Global Inspiration and Local Implementation
Inspired by a pioneering water fund in Quito, Ecuador, this model has been replicated in over 30 cities worldwide, including 16 in Africa. It operates on the principle that preventing water issues at the source is more cost-effective than addressing them downstream. "This model is delivering what growing African cities need: reliable, affordable water in a changing climate," said Ademola Ajagbe, regional managing director for Africa at TNC.
Structured as a public-private partnership, the Nairobi fund involves entities like Coca-Cola and East African Breweries. Initially raising 25 million shillings, it has now accumulated 500 million shillings in an endowment fund managed by GenAfrica. Fred Kihara, the fund's partnership director, notes, "We convinced corporations that for every dollar invested upstream, it would generate two dollars downstream. That business case depends on incentivising farmers within the watershed."
Personal Stories of Resilience and Innovation
Francis Mburu, a 75-year-old farmer, faced water challenges despite living near the Aberdare mountain range. In 2020, he installed water harvesting structures, including a 100,000-liter pan, and terraced his farm to control erosion. "I now harvest water from my farm rather than rely on the nearby stream, while the terraces help water seep into the soil with very little silt going into the river. These methods mean more food for me and more clean water downstream," Mburu says.
Stephen Matu, evicted from Mount Kenya forest in 2009, transformed his half-acre farm in Solio with two water pans, turning it into a seedbed for fruit trees and vegetables. Similarly, John Maina, a 31-year-old farmer in Murang'a county, adopted water harvesting techniques to avoid river pumping, preserving clean water supplies. "I would have ended up in a debased lifestyle had these people not helped me improve my farming methods," Maina reflects, noting he has trained over 50 young people in modern agriculture.
Future Challenges and Community Benefits
Caroline Wangari, a field extension assistant, emphasizes that the fund's interventions, though not cash-based, have catalyzed economic empowerment. "The last decade has convinced us that providing farmers with water pan liners or tree seedlings has been a catalyst for community economic benefits," she says, highlighting how economic incentives drive conservation efforts.
The Upper Tana-Nairobi water fund trust is praised for reducing treatment costs, improving water quality, and enhancing ecosystem resilience. However, it requires increased sustainable financing, stronger private-sector involvement, and deeper community engagement to scale the model to other Kenyan cities and ensure long-term benefits.
