One World

Project: Transboundary water analysis

Client: OneWorld Sustainable Investments for the Regional Climate Change Programme (Department for International Development, UK)

Location: SADC region

Timeframe: 2009

The RCCP commissioned Pegasys Strategy and Development to undertake an integrative analysis of climate impacts on transboundary waters. The main purpose of the study was to understand better the future of climate-water relationships in the SADC region. Implicit in the work is the understanding that the impacts of climate change cannot be evaluated without considering the status of development now and in the future—climate change impacts and the status of development go hand-in-hand.

Three Southern African river basins were chosen for the analysis—the Okavango, the Limpopo and the Zambezi, each being representative in their own ways of larger regions. The mode of analysis was heuristic and qualitative—relying on expert opinion rather than quantitative modelling.

Uncertainty in future climates and socioeconomic conditions are dealt with through scenarios. Bound futures (envelopes) reflect the interplay of climate scenarios and development scenarios. Thus, two climate futures considered moderate wetting and significant drying scenarios, along with temperature increases of 1.5°C to 3°C, although the magnitude of these changes are not uniform over the whole region. Development futures also considered two scenarios; one of uneven growth, which is the current condition and in which unconnected nodes in the region grow economically at about 3-5% annually. The second development scenario is that of integrated regional development, capable of six to eight percent annual economic growth and implies strong trade, high levels of urbanisation , international investment and inter-connected regional infrastructure.

Water-related themes considered in these scenarios incorporate the environment (including aquatic ecosystems); fisheries productivity; rural and domestic stock water use (particularly regarding groundwater); rainfed and irrigated agriculture; hydropower; bulk industrial (including mining) and urban requirements; human security (floods); rural livelihoods and water utilisation. Using these themes as a basis, different potential futures for each river basin emerged.

In the Okavango, the differential hydrological response of the Cuito and Cubango tributaries create a possible threatening upstream scenario, depending on which tributary system is developed for irrigated agriculture and hydropower. Economic development could be limited to possible irrigated agriculture and hydropower on the Cubango River. Then, baseflows in the Cuito River provide some means of maintaining baseflow to the Okavango delta. Climate futures anticipate a possible drying from the south. Rural communities in the delta area are then increasingly vulnerable to declines in groundwater if drying takes place. The possibility of threats to the world-famous Okavango delta system by upstream developments, in both the Cuito and Cubango tributary basins, then require an early start to transboundary planning cooperation.

In the Zambezi basin, a multiple of sectors are affected by possible climate changes and interactions with development; fisheries, rainfed agriculture, hydropower, the natural environment, human security (by flooding and drought, although seasonal flooding in general as an enabler of production), and urban and industrial water demands. The upper Zambezi is the source of most water in the river and the future position of the Intertropical Convergence Zone (ITCZ) over this region will be an important determinant of this region’s prospects. Extreme poverty is widespread at present and there is a overwhelming reliance on subsistence agriculture. Occasional severe droughts have devastating effects on livelihoods, mostly because irrigation is poorly developed. The river basin is also a focus area for hydropower development and these installations will ultimately significantly influence river flows, with knock-on effects for agriculture, ecological functioning and the human occupance of flood-prone lands. Changing drought frequencies will have substantial effects on hydropower production in the Zambezi basin and further implications for the interactions of agriculture and hydropower production. Mining is another key factor in the basin’s economy, occuring mostly on the watershed and is a source of pollution, the concentration of which will increase during dry periods. Flooding is a particular problem in the delta but the intensification of riparian agriculture will extend flood-related impacts along much of the main river and a few of its important tributaries such as the Kafue.

The Limpopo basin is however very different to the other two basins. Its key feature is the heavy industrialisation and population concentration in its upper reaches (Johannesburg/Pretoria), but includes the intense mining development in the Bushveld (platinum), the coalfields of the South African Highveld and Waterberg, and the thermal electricity generation in place or being built. This region is growing the fastest in economic terms but its climate is strongly affected by high variability and water already is scarce. Pollution is a major and increasing problem. More water for irrigation purposes is unlikely to become available and proposed downstream irrigation developments in Mozambique are unlikely to be realised. Groundwater will increasingly be important to the survival of a large number of people. Climate changes which increases variability even more so will cause increased stresses on all sectors of the economy, some of which will be mitigated by the high levels of infrastructural development and interbasin transfers from the Lesotho Highlands Water Scheme. However, transboundary water politics is likely to become increasingly important.

Conclusions

Overall, conditions for sustaining livelihoods in already marginal areas are likely to become increasingly difficult, for example in the lower parts of the Limpopo basin. These challenges will result in increased urbanization where those peri-urban populations become increasingly at risk from exposure by a variety of pathways to the characteristics of the evolving climate. Water supply to some of these urban nodes is already becoming a problem. In general, increased irrigation demand will be a key feature of the future and this has to be played off against competing users. Crops may shift to lower-water utilizing types but this may possibly be at the expense of nutrition benefits.

Macro-economic shifts to a greater water use efficiency emerge (including agriculture, energy production, industry and urban development, linked to improved technical water use efficiency. Adaptive water institutions will be required; these have the attributes of a) clear strategic direction and objectives; b) decentralized institutional responsibilities; c) organisational flexibility and multi-skilling; and d) organisational learning and institutionalization of knowledge (based on operational experience). Flexible water allocation systems will also be needed and these have the attributes of appropriate policy and legislative frameworks, strategic planning of water allocation according to development priorities, and operationalising through effective licensing and enforcement. Active engagement is required at basin-level through the SADC-context of the Protocol on Shared Water Resources.

Flexibility of water resource management is ultimately best served by not fully allocating all water resources early, thereby giving room later for new options. The careful management of groundwater resources is particularly necessary because aquifers are easily overexploited and the most vulnerable people in SADC are dependent on them. However, there is also a general lack of understanding regarding the climate implications for groundwater, including transboundary aquifers. This shortcoming is critical considering that the majority of people in the region are dependent on this resource.