Two water allocation models were developed in this project as a tool to support policy evaluation and improve strategic and operational decision making procedures of ARA-Sul. WEAP (Water Evaluation And Planning) was chosen as modelling framework. Different scenarios were implemented in WEAP to show the impacts of possible changes and the effects of possible adaptation measures. The ARA-Sul staff was actively involved in the project during several distance training sessions and a training mission in Mozambique.
The Incomati River Basin is located in the eastern region of southern Africa and is shared by South Africa, Swaziland and Mozambique. Economic developments resulting in increased water use in the basin have been tremendous since the 1970s. Water is used by forest plantations and for domestic and industrial use, while irrigation is the major water user. From the late 1960s major dams have been commissioned that allowed increased water withdrawals at increasing levels of assurance. Currently construction work on Moamba Major, a new dam on the Mozambican part of the Incomati River, and expansion of the Corumana dam on the Sabie River, a main tributary of the Incomati River, are ongoing. After completion, water from these reservoirs will be used to supply water to Maputo (capital of Mozambique) and to further increase the irrigated area, mainly of sugar cane plantations. All these developments have boosted the economies of the three riparian countries, but have also impacted on the environment.
Sustainable management of the Incomati water resources is one of the responsibilities of ARA-Sul. ARA-Sul is facing the challenge to meet water demands; long-term water availability is decreasing (due to climate change), while the growing population, the increase in agricultural areas and industrial development results in an increased demand for water. To overcome this challenge, effective and targeted water management is necessary and therefore the existing decision making procedures had to be improved. ARA-Sul takes decisions on both the strategical and operational level. Examples of strategic decisions are the construction of new and/or the expansion of existing reservoirs, inter-basin transfers, and the renewal of the distribution network. Granting permits for new water users, and managing the daily releases from existing reservoirs are examples of operational decisions.
Two water allocation models were developed in this project as a tool to support policy evaluation and improve strategic and operational decision making procedures. WEAP (Water Evaluation And Planning) was chosen as modelling framework. Different scenarios were implemented in WEAP to show the impacts of possible changes and the effects of possible adaptation measures. The ARA-Sul staff was actively involved in the project during several distance training sessions and a training missions in Mozambique. During these training sessions they interactively learned to apply and extend the developed models.
The project took place in the Incomati River Basin and was carried out using a similar approach as for the pilot study that was undertaken in the Umbeluzi basin in 2014. The project will likely be extended to other basins that are managed by ARA-Sul. Furthermore, other ARAs (e.g. ARA-Centro) are involved in similar projects and work with the same modelling framework. In this way the water management organizations in Mozambique can share their knowledge and experience and accelerate the capacity building process.
2016 - FutureWater Report 154
Water Allocation Models for the Incomati River Basin, Mozambique
De Boer, F.S., P. Droogers