Water Storage Projects

It has been recognised for some time now that climate change will exacerbate natural variability. Even if total rainfall increases it is likely to become more irregular in intensity and duration (Bates et al., 2008). This is a huge problem for the African continent where water is already scarce. One way of adapting is through water storage projects providing a constant water supply despite uncertainty in the African climate, particularly for agricultural use. Options for water storage include dams for artificial water storage, soil moisture enhancement, natural wetlands, groundwater aquifers and ponds or small tanks to harvest runoff.

There has been a recent proliferation in funding for programmes of this kind in Africa. The World Bank believes water resource schemes provide the basis for broad regional development (2004) and has increased lending to these projects by 50%. At the G8 summit in 2005 the Infrastructure Consortium for Africa was established committing large amounts of aid to water infrastructure development. The EU has also pledged further aid to water storage projects, particularly in Africa. This is backed up in the report ‘Climate Change: Impact on Agriculture and Costs of Adaption’, where Nelson et al. make recommendations focussing on greater investments in agricultural science and technology to meet the food security demands of increasing population. They argue that food security and climate change adaption go hand in hand, and an additional $7 billion per year is needed to fund adaptation programmes to finance the research, rural infrastructure, and irrigation investments to offset the negative effects of climate change on human well-being. 

However the positive motive behind the donations to these projects has not necessarily led to a positive outcome. In research for the International Water Management Institute, McCartney et al. show the science required for planning and building water storage is often inadequate. In their report they find the understanding of flow and sediment regimes necessary for dam design, knowledge of aquifer extent and recharge for groundwater exploitation and understanding of current climate change variability was often insufficient. “As a result design failures are common, benefits are frequently sub-optimal and, in the worst cases, investments worsen rather than improve people’s well-being” (McCartney et al., p.5).  

Future climate change has the potential to impact water storage projects already in place. As water becomes more scarce the effectiveness of infrastructure may change. Climate change risks for different storage types in Sub-Saharan Africa and the possible social and economic implications are shown in the table below. An example is that of soil moisture in arid regions where reduced rainfall and longer dry periods could mean soil and water conservation methods may fail to increase and maintain soil moisture as planned (McCartney et al.; Chiew et al., 1995; de Wit and Stankiewicz 2006). Further problems exist with regards to health. Boelee has found larger availability of open water surface may increase the transmission of water-related diseases; increased schistosomiasis is associated with small reservoirs in Burkina Faso and malaria around large dams in Ethiopia (2013). 

Climate change risks for different storage types in Sub-Saharan Africa and the possible social and economic implications

Water storage options need to be planned and managed carefully with their potential impacts, particularly regarding climate change, in mind. Future variations need to be considered to ensure projects will still operate and be of use for years to come. Western institutions willingly donate huge sums of money to fund water programmes but African nations may feel they have little ownership over them. Therefore they may not put sufficient care into their organisation and have limited interest or knowledge of the repercussions. If money is being given towards projects of this nature, considerations need to be taken by donors to ensure they are appropriate projects with hopefully few problems in years to come.  Managers with sufficient expertise and experience need to assess potential impacts at all levels and scales before building water storage infrastructure, and weigh these against the benefits. Water storage solutions may be necessary for food and health security in many parts of Africa but projects must be undertaken with care.