Dams, farms and nature reserves all want the same water. Someone will lose
By Joyce Karimi
Few rivers carry as much economic weight for Kenya as the Tana. Rising from the Aberdares and Mount Kenya, it supplies drinking water to the capital, powers the national grid, irrigates farms and sustains one of East Africa’s most ecologically significant deltas. It also exposes the country’s deepest development dilemma: how to balance energy security, food production and conservation in a warming, water-stressed economy.
Covering roughly 22 per cent of Kenya’s land area and supporting close to 18 per cent of its population, the Tana River Basin is the backbone of the country’s water economy, according to the United Nations Environment Programme (UNEP). Its importance, however, has made it a site of intensifying competition rather than coordination.
A river that runs the economy
The upper Tana supplies between 80 and 95 per cent of Nairobi’s water, depending on rainfall, through a system of dams and transfer tunnels managed by the Athi Water Works Development Agency and Nairobi City Water and Sewerage Company. The same river also anchors the Seven Forks hydropower cascade, which includes the Masinga, Kamburu, Gitaru, Kindaruma and Kiambere dams.
Together, these facilities account for about 570 megawatts of installed capacity and typically generate more than two-thirds of Kenya’s hydropower in wet years, according to data from KenGen, the state-owned power producer.
“Kenyans should be assured that we are managing the dams to balance power generation and downstream water needs,” Peter Njenga, KenGen’s managing director, said in a 2024 briefing on reservoir operations as rainfall patterns became more erratic.
The stakes extend beyond electricity and urban taps. Agriculture remains the basin’s largest water user. Smallholder farmers in the upper catchment depend on rainfall and river flows, while large-scale irrigation schemes in the lower Tana aim to expand rice and maize production in pursuit of food security.
The Tana and Athi Rivers Development Authority (TARDA) estimates that the lower basin alone has the potential to irrigate more than 200,000 hectares, a figure that has driven renewed interest in flagship projects such as Galana Kulalu and the proposed High Grand Falls multipurpose dam.
Growth plans meet ecological limits
These ambitions collide with ecological reality. The Tana Basin is already showing signs of strain from land-use change, deforestation and climate volatility. UNEP estimates that sedimentation from degraded upper catchments is reducing reservoir storage and shortening the operational life of hydropower dams, while increasing water treatment costs downstream.
The consequences are visible in the delta. Designated a Ramsar Wetland of International Importance, the Tana Delta supports fisheries, flood-recession farming and pastoral livelihoods. It is also one of Kenya’s most biodiverse landscapes. Yet mangrove loss, altered flood regimes and upstream abstractions have weakened its resilience.
“Millions of people depend on the ecosystem services of the Tana Delta, from fisheries to grazing land,” Ramsar Secretariat officials noted in a recent assessment of African wetlands under climate pressure. “When upstream decisions ignore downstream impacts, the costs are borne by the most vulnerable.”
Drought has sharpened those costs. Tana River County experienced successive failed rainy seasons in 2023 and 2024, prompting emergency water trucking and heightening tensions over access to riverine land, according to county government reports cited by Kenya News Agency.
Whose water, whose voice
Competition in the basin is not only between sectors but also between levels of power. National infrastructure projects are planned in Nairobi. Their impacts are felt hundreds of kilometres downstream.
Disputes over land and water access have increasingly found their way into court. In 2024, a High Court order temporarily halted expansion activities along the Tana River and Garissa county boundary amid claims of unlawful encroachment, reflecting how resource pressure is fuelling political and communal friction, as reported by Kenya Broadcasting Corporation.
Civil society groups argue that existing governance frameworks are not keeping pace with these pressures. Kenya’s Water Act provides for integrated catchment management through basin area boards and water resource user associations. In practice, coordination across energy, agriculture, water and conservation agencies remains weak.
“The challenge is not a lack of laws but fragmented implementation,” said a senior water policy analyst at Wetlands International in a briefing on the Tana Basin. “Each sector optimises for its own objectives, often at the expense of the system as a whole.”
Putting a price on nature
One attempt to bridge these divides has been to frame conservation in economic terms. UNEP’s valuation of ecosystem services in the Tana Basin found that investments in watershed protection could deliver returns by reducing sedimentation, stabilising water supply and lowering infrastructure costs.
“Recognising the economic value of freshwater ecosystems helps decision-makers see conservation not as a constraint but as an investment,” said Joakim Harlin, then head of UNEP’s freshwater ecosystems unit, during the launch of the assessment.
That logic underpins the Upper Tana-Nairobi Water Fund, a public-private partnership that channels corporate and donor finance into soil conservation, agroforestry and riparian restoration upstream. The Nature Conservancy, which helped design the fund, estimates that every shilling invested yields multiple returns through improved water quality and reduced treatment costs.
Private sector participation has followed. Kenya Breweries Limited committed KSh54 million to watershed protection in 2024, while KCB Foundation announced additional support in 2025. “Protecting the health of the Tana is essential for long-term economic stability,” said Emmanuel Rurema, executive director of the Water Fund, at the signing of the KCB partnership.
A systems problem demands a systems response
The Tana River Basin illustrates a wider African challenge. Rivers are being asked to do more at the very moment climate change is making their flows less predictable. Energy transitions, food security agendas and urban growth plans increasingly converge on the same finite water systems.
What is missing is a genuinely integrated approach that treats the basin as a single economic and ecological unit. That means aligning dam operations with ecological flow requirements, tying irrigation expansion to catchment restoration and giving downstream communities a meaningful voice in upstream decisions.
Kenya’s experience suggests that technical solutions alone will not suffice. The future of the Tana depends as much on governance and trust as on rainfall and infrastructure. Without a shared systems view, the river risks becoming a source of recurring crisis rather than sustained prosperity.
