WISE-UP to Climate

Water Infrastructure Solutions for 
the Tana Basin


The Tana, Kenya's longest river, flows for over 1,000 kms with a catchment area of 95,000 km² (roughly the size of Portugal). The River Basin has significant development opportunities for hydropower, domestic water provision, and irrigation - planned as part of Kenya's Vision for 2030. The basin provides 65% of the national electricity needs from hydropower, and nearly all of Nairobi's domestic water supply for 4 million people. It does this through a series of water transfers and dams in the Upper Tana Basin. The basin also supports the livelihoods of around 6 million people, and is home to major biodiversity hot spots – some amphibian species are even named after the river.

Yet, within the basin there is fierce competition for water resources between many different activities and actors. These include irrigation, fishing, horticulture, rice production, hydropower, domestic water use, factories, and drinking water for Nairobi, as well as major growing towns such as Thika, Nyeri, and Karatina.

It is, in economic and social terms – a going concern for the Kenyan nation.

A critical challenge for the Tana River and those who manage it, will be to adapt water management to climate change impacts and urban growth. At the same time, ways must be found that can help share the benefits equitably amongst the different users with different needs. 

"In efforts to meet the sustainable development goals and Kenya's VISION 2030, the tools and skills from WISE-UP are critical to sensitize key stakeholders in the Tana basin on the use of evidence-based data to support decision making. We need better tools that can help us scale our development opportunities to adapt to climate change and build resilience" ~Eric Odada, WISE UP Tana Basin Lead

A key part of the WISE-UP research is to understand the political-economic context in which decisions about river basin development are made. The aim is to better understand the interests of different stakeholders and their influence over investment choices, as well as the constraints they face. This helps identify opportunities to support positive changes in policy and planning, for equitable, sustainable and climate-compatible solutions. The ODI-led research centres on several case studies, outlined in an upcoming report and discussed in this blog: 'Inclusive Water Development: experiences from the WISE-UP project'

The Tana River supplies 95% of the water for Nairobi's 4 million residents ©Shutterstock /Eunika Sopotnicka


Over the past 50 years, agricultural intensification and expansion in the Upper Tana basin has led to increased soil erosion and river sedimentation. This has led to reduced farmland productivity and has adversely affected the performance of downstream water infrastructure such as dams and water treatment facilities. The challenge to increase downstream water quality and quantity, and to provide positive benefits for the upstream farmers has led to the establishment of the Upper Tana-Nairobi Water Fund. The Fund is working to restore key areas of the upper watershed to improve downstream water quality.

The impacts of climate change on the Tana River are uncertain, but are expected to lead to an increase in rainfall variability, sometimes dramatically so. This will affect river flows, and the way the current dams and irrigation systems perform, leading to challenges in how the basin adapts to climate change – can it provide more electricity, grow more food, sustain an increasing population, and secure the integrity of ecosystems and the services they provide for millions of people?

This brings challenges to the institutions tasked with managing the river and the sectors reliant upon it. The strategic significance of water storage infrastructure is clear – and therefore often the conventional response is to build more

In recent years though, an alternative perspective has been advocated for the Tana, primarily because of the adverse environmental and social impacts associated with further expanding built infrastructure, and the uncertainty of climate change. 

WISE-UP uses new tools and approaches to consider the role of natural infrastructure as a large scale 'nature-based solution' for climate change adaptation. 

By using mixed approaches: built infrastructure for the reliable and constant services delivered at scale (such as electricity), and natural infrastructure for the benefits it brings to built infrastructure, and the broad range of co-benefits it provides to people and biodiversity. 

The project has worked to develop the methodologies using cutting edge tools, and developed the evidence base for natural infrastructure as a scale-able adaptation solution. The Nairobi Water Fund is an excellent case of investments in nature to support built infrastructure. 

More on this work 'Built or natural infrastructure: a false dichotomy' by Matthew McCartney & James Dalton from IWMI and IUCN

"Water is everyone's business. Scientists have made a clear case: For every $1 invested in conservation, we avoid $2 in future costs" Eddy Njoroge, Nairobi Water Fund President

©Shutterstock/Magdalena Paluchowska/


Basin lead partner ACCESS -the African Collaborative Center for Earth System Sciences- has worked with key basin stakeholders to develop possible scenarios for the development of the Tana River basin. Their workshops function as dual opportunities to build (i) capacity, understanding, and dialogue amongst diverse stakeholders, and (ii) technical implementation using project data to demonstrate trade-offs and options.

They aim to develop skills and competencies among participants in the design and use of basin scenarios to inform decision-making and planning for alternative natural and built infrastructure options under a changing climate.

Press Article SciDevNet: Water security project seeks inputs to guide next steps

System scale understanding needs the development of processes that allow stakeholders to understand and then negotiate their needs – recognizing the broad range of different benefits and impacts they require.

WISE-UP has worked to build a platform for cross-sectoral dialogue with the integration of climate change information and data to help improve understanding and network institutions together.

"The recognition of the local water resource users as decision-makers in the design of infrastructure projects provides an opportunity to explore long term adaptive capacities of the vulnerable communities. The more they understand, and we learn from them, the better we all are at dealing with stresses, shocks and crises that may arise due to climate, land use and ecosystem changes" ~Elizabeth Diego, Lusimba Water Resources Authority, Community Development Expert
"Integrated Water Resources Management is the back bone for sustainable hydroelectric power generation. WISE-UP has provided tools and skills necessary for participatory and multi-stakeholder engagement in energy related water infrastructure planning" ~Willis Owino Ochieng, Chief Energy Planner, Kenya Electricity Generating Company (KENGEN)

More on this work: 'Participatory Scenarios development as social learning tool in the Tana River Basin' by Washington Ochola & Christine Omuombo, ACCESS.

WISE-UP proposes a redesign of conventional approaches; one that works with, rather than against natural systems, whilst simultaneously optimizing the performance of engineered infrastructure. 
Ecosystem services mapping exercise ©BC3/Laetitia Pettinotti


IWMI -the International Water Management Institute- has worked to define "benefit functions" for the basin: quantifying the relationships between river flow and ecosystem services, and how climate change may affect this.

Stakeholders helped WISE-UP to prioritize ecosystem services in the basin based on social importance, climate change impacts, and challenges to date based on the current use of dams in the basin. Services includes seasonal floodplain fish catch, flood recession agriculture, reservoir fisheries, estuary fisheries, floodplain cattle grazing, and sediment transport through the delta to the coast. Sediment transport from source to sea is important as it helps maintain beaches that are valuable to Kenya's tourism industry, and may be critical in limiting coastal salinisation of freshwater systems. 

Maintaining flood flows is important for habitat regeneration and biodiversity needs, informal agriculture and livestock grazing. Pastoralists in the lower part of the basin travel long distances to graze their cattle, goats, sheep and even camels on the Tana floodplain. At any given time it is estimated that between one and two million animals graze in the lower Tana.

During droughts the contribution of the floodplain to the pastoral economy becomes critical as other grazing areas dry up. WISE-UP estimates the current economic value of floodplain grazing as approximately USD 140 million per year, contributing to the livelihoods of many tens of thousands of people.

By regulating river flows, the current stock of dams in the basin have reduced these benefits, including the value of floodplain grazing. Depending on climate change and river flow impacts, more dams are planned in the basin. It is critical that adaptation is used as a driver for sustainable development in the Tana, supporting downstream livelihood opportunities and livestock, as well as other floodplain benefits and biodiversity


One important lesson learned from the project is that relationships are not always easy to predict in complex systems and can sometimes be counter-intuitive. For example investing in upstream natural infrastructure, such as soil conservation measures, can reduce sediment entering the river, and so reduce sedimentation in downstream reservoirs. However, decisions may be made to use this additional reservoir storage (due to less sediment) to maximise hydropower production. So far so good. However, this may reduce water available to downstream ecosystem services, such as floodplain fisheries, because more water is stored in the reservoir. In dealing with changes in water flows, trade-offs abound.

More on this work: 'Striking a balance between nature and development', by Matthew McCartney

"Dams and other built infrastructure are essential for socio-economic development. Through WISE-UP we can influence future planning and investment in ways that continue to facilitate economic growth in response to climate change, but which are more equitable and sustainable" ~ Matthew McCartney, leader of IWMI's Water Futures 
Gitaru Dam, Tana basin, Kenya ©University of Manchester/Anthony Hurford 


Understanding the complexities of water management and climate change impacts at scale needs state-of-the-art tools. WISE-UP modeling seeks to quantify the trade-offs generated between different uses of available water resources, and different priorities between ecosystem services. While river basin benefits to stakeholders are generated by both built and natural infrastructure, decisions supporting these benefits often conflict. Using models has helped stakeholders and scientists alike to understand the relationships between natural and built infrastructure under different river flows, and better identify ways to balance the benefits from and to the river. 

Models are powerful tools to help understand the dynamics of the Tana river, and the impacts of climate change upon it. It's at the negotiation of the results that the power imbalances become clear, and the positions of stakeholders become motivated by a range of needs and pressures. WISE-UP has used this often difficult conversation to bring stakeholders to agreed perspectives on the trade-offs that changes in river flows create. Through better understanding possible impacts, WISE-UP provides information that is valid to all sectors who have to equally adapt to climate change impacts.

"By working with stakeholders to co-develop metrics of river basin performance, we can make sure their interests are properly represented in WISE-UP analysis" ~ Anthony Hurford, University of Manchester

Research and analysis by the University of Manchester (UoM) can demonstrate trade-offs in a multitude of ways. The infographic below shows three options for operating the current system of hydropower dams in the Tana Basin. River flows are simulated with a tailor made SWAT model developed by IWMI, using future river flows based upon the ICHEC 45 climate scenario.

All the options clearly show that additional benefits could be available if river flows increase in the future, but also that the balance of benefits between sectors could be managed.

What is important is the appropriate balance of benefits both from the basin and within the basin. Balancing national and basin development, and upstream and downstream needs is a huge opportunity for natural infrastructure investment.

More on this work: 'Balancing complexity and simplicity: the challenge of (re)packaging science for decision-making and policy relevance', by Anthony Hurford & Evgenii Matrosov from The University of Manchester

"WISE-UP has created new conversations across sectors and stakeholders. These have led to greater understanding and recognition of climate change impacts and opportunities. Stakeholder needs and priorities have effectively created a pipeline of adaptation interventions which can help to mobilize NDC (Nationally Determined Contributions) implementation - and importantly investment." Dr James Dalton, a.i. Director IUCN Global Water Programme

WISE-UP has shown us that ecosystems and the services they provide are adaptation solutions that need quantification and investment. These are development issues that need to sit alongside built infrastructure and other development decisions. 

To create collaborative basin planning that is adaptation ready requires platforms for cross-sectoral dialogue. The Kenyan Climate Change Act (2016) provides an exciting opportunity to strengthen national institutions for strategic planning, and provides a framework to mainstream climate adaptation and mitigation into national and county planning and budgeting processes.

For more information on 'WISE-UP to Climate', visit www.waterandnature.org/wiseup or use #Wise2Climate hashtag via social media

The Tana River, Kenya's lifeblood, strains under development and drought ©Mongabay; Thirsty city: after months of water rationing Nairobi may run dry ©The Guardian; As The Climate Changes, Kenyan Herders Find Centuries-Old Way Of Life In Danger ©NPR

WISE-UP also works in the Volta Basin, see this Shorthand 'WISE-UP to Climate: Water Infrastructure Solutions for the Volta Basin'