Project : Re-Thinking water storage for Climate change adaptation in Sub-Saharan Africa



Africa’s rural poor with their limited choices, inadequate access to resources and climate sensitive livelihoods, are at risk from climate variability. Throughout sub-Saharan Africa, existing climate variability, and insufficient capacity to manage that variability, lies behind much of the prevailing poverty and food insecurity. Climate change is predicted to further undermine the livelihoods and well being of millions of people through adverse impacts on crop production, seasonal water resources, disease prevalence, crop pests, and other climate sensitive aspects of rural life.
Water availability is a critical factor in determining the impacts of climate change in Africa. Increased water storage is widely promoted as a major component of adaptation strategies. The idea is that by increasing both water and food security and increasing adaptive capacity water storage can reduce vulnerability to climate (Figure 1). However, to date there has been little systematic analysis of how climate change may affect existing water storage or how to account for climate change in the planning and management of new water storage. The risk is that ill-conceived water storage may be undermined as a consequence of climate change. At best this would mean current investments are a waste of scarce financial resources. At worst it may mean they aggravate the negative impacts of climate change.
Figure 1:Water storage as an adaptation strategy to reduce climate vulnerability
This study focuses on physical water storage in its various different forms. These forms can be conceptualized as a continuum, ranging from water stored in underground aquifers, through the soil profile to that stored in large reservoirs (Figure 2). In any specific situation, each of these types of storage has its own niche in terms of technical feasibility, socioeconomic sustainability, institutional requirements and impact on public health and the environment. By affecting the performance, cost and externalities of different types of water storage, climate change will alter their effectiveness and suitability.
Figure 2:Conceptualization of the physical water storage continuum


The primary aim of this project is to develop guidance on methods for better inclusion of climate change in the planning and management of the full range of agricultural water storage options. The guidance will encompass approaches to evaluating:
  • the socio-political, institutional and biophysical conditions under which various storage options should or should not be implemented – when and where are they appropriate?
  • which investments in water storage improve resilience and reduce risk for farming communities - how are climate change issues best built into decision making?

 The research questions 

  • How do people cope with current rainfall and water variability? 
  • How are different types of storage managed in terms of access, institutions and the distribution of benefits?
  • How is climate change being factored into plans for water and agricultural development?
  • How can the need for water storage and the effectiveness and suitability of different storage options be evaluated and compared for different climate scenarios?
  • How can water resource planning and management processes be modified to better account for the uncertainties arising from climate change?


The project is a multi-disciplinary study being conducted in Ghana (the Volta Basin) and Ethiopia (the Nile Basin). The project is operating at both the basin scale and on smaller watersheds located within the basins (i.e. the Vea, Golinga and Sata in the Volta and the Koga, Gumera and Guder in the Nile).  
The basin analyses are being undertaken to evaluate the biophysical implications of different climate change scenarios on different types of water storage. This approach adopted includes: i) down-scaling of GCM scenarios to the basins; ii) hydrological simulation of the consequences of changes in climate for runoff and flow, including impacts on the frequency of extreme events; iii) evaluation of the implications for storage in relation to technical effectiveness (i.e. resilience, reliability and vulnerability).  
The watershed analyses are being undertaken to evaluate the possible implications of climate change on socio-economic factors. The studies comprise both surveys and participatory and anthropological investigations to provide information that can be used to determine the suitability of different storage types taking into account such things as externalities, cost-effectiveness and poverty reduction potential.      
Lessons learned from both the basin and catchment scale studies will be combined to develop the guidance and to arrive at integrated policy relevant recommendations. 

Project leader

Dr. Matthew McCartney (

IWMI Researchers

Project Duration

Three years: 2008 - 2011


IWMI Sub Regional Office for Nile Basin & Eastern Africa (Addis Ababa- Ethiopia)
and IWMI Sub Regional Office for West Africa (Accra-Ghana).