Ethiopia is the main source of the Nile River, and the country urgently needs water for irrigation and hydro-electric power development. To-date, however, Ethiopia is the country in the Eastern Nile basin that uses the least amount of water from the Nile run-off.
Norplan, Norconsult and Lahmeyer International, Karadobi Multipurpose Projet pre-feasibility study (Final Report) – vol. 5, Initial Environmental Assessment, Technical Report, Ministry of Water Resources, The Federal Democratic Republic of Ethiopia, 2006. reapplied this framework specifically considering the GERD, showing strong economic benefits of cooperation. Similar to the studies mentioned previously, this framework assumes optimized reservoir management across the international borders, which effectively replaces existing management with an ideally coordinated system.
Managing the basinâ€™s water resources is complex because of its trans-boundary nature, exacerbated by environmental degradation and strong climate variability. The Nile basin water resources have been extensively studied during the last 125 years for planning and management purposes, in particular with regard to the use of blue water in the downstream part of the basin, though recently some studies have also focused on the upper parts.
The proposed methodology relies on the stochastic dual dynamic pro-gramming (SDDP) model to derive monthly or weekly operating rules for multipurpose multireservoir systems taking into account the stochasticity of the inflows, irrigation wa-ter withdrawals, minimum/maximum flow requirements for navigation, fishing and/or for ecological purposes. In SDDP, release decisions are chosen so as to minimize the op-erating costs of a hydrothermal electrical system.
The equitable sharing of benefits in transboundary river basins is necessary to solve disputes among riparian countries and to reach a consensus on basin-wide development and management activities. Benefit-sharing arrangements must be collaboratively developed to be perceived not only as efficient, but also as equitable in order to be considered acceptable to all riparian countries. The current literature mainly describes what is meant by the term benefit sharing in the context of transboundary river basins and discusses this from a conceptual point of view, but falls short of providing practical, institutional arrangements that ensure maximum economic welfare as well as collaboratively developed methods for encouraging the equitable sharing of benefits. In this study, we define an institutional arrangement that distributes welfare in a river basin by maximizing the economic benefits of water use and then sharing these benefits in an equitable manner using a method developed through stakeholder involvement. We describe a methodology in which (i) a hydrological model is used to allocate scarce water resources, in an economically efficient manner, to water users in a transboundary basin, (ii) water users are obliged to pay for water, and (iii) the total of these water charges is equitably redistributed as monetary compensation to users in an amount determined through the application of a sharing method developed by stakeholder input, thus based on a stakeholder vision of fairness, using an axiomatic approach.
The paper ends with suggestions on how to deal with open questions and lessons learned from the ongoing NBI process. Since 1999 a multilateral effort termed the Nile Basin Initiative has been underway among the Nile riparians to explore opportunities for maximizing the benefits of the river’s waters through cooperative development and management of the basin. However, to date there has been virtually no explicit discussion of the economic value of cooperative water resources development.
These studies show that there is no convergence of development plans emerging among the Nile riparian countries. This paper reviews river basin water resource models as applied in the Nile River Basin, distinguishing between simulation, optimization and combined simulation and optimization models. The paper concludes by identifying knowledge gaps to guide future research on water resources planning and management in the Nile. Strategies for filling the Grand Ethiopian Renaissance Dam and implications for downstream water resources are analyzed using a river basin planning model with a wide range of historical hydrological conditions and increasing coordination between the co-riparian countries.
Arjoon et al. (2014) evaluated the longterm impacts of the GERD on the economic benefits of Ethiopia, Sudan, and Egypt and concluded that the GERD would increase the minimum annual economic benefits of the three countries from 4.9 to 5.6 billion US$, provided that Sudan fully uses its water share according to the 1959Nile Water Agreement (UN, 1964 and Ethiopia implements its planned irrigation schemes around Lake Tana. Arjoon et al. (2014) , applying a stochastic dual dynamic programming (SDDP) approach to assess the impact of the operation of the dam on the Eastern Nile economies, shows that water storage in the GERD would benefit downstream countries through improved irrigation and hydropower development and reduced hydrologic risks, particularly during dry years. Water resources development projects often involve multiple and conflict-ing objectives as well as stochastic hydrologic inputs. Multiobjective optimization tech-niques can be used to identify non-inferior solutions and to construct a trade-off rela-tionship between conflicting objectives. This paper presents a methodology for analyz-ing trade-offs and risks associated with large-scale water resource projects under hydro-logic uncertainty.