Exploring Cooperative Transboundary River Management Strategies for the Eastern Nile Basin

Challenges and prospects of transboundary river water conservation and watershed protection in Ethiopia: The case of the upper Blue Nile

This article aims to present the challenges and prospects of transboundary river water conservation and watershed protection in the Upper Blue Nile basin. The River Nile Basin embraces eleven countries shaping their diverse environments and playing a vital role in the livelihoods of its inhabitants. Within this context sharing and managing the River Nile water resources has been a persistent challenge and a potential source of conflict. The Blue Nile River is shared by Ethiopia, Sudan and Egypt and for the latter it is the life artery as the majority of the water reaching Egypt comes from the Blue Nile. Only Egypt and Sudan have an agreement to share the water and there is a need to revisit this mode of resource use based on water allocation among the River Nile countries and especially for the Blue Nile. Nevertheless, these issues have not been resolved and have exacerbated by the commencement and near operation of the GERD. Another important aspect dealt with in this article is the conservation and watershed protection. The study used a qualitative research approach, and data were collected through key informant interviews. Different relevant secondary sources are also consulted. The data were analyzed based on a thematic analysis approach. The key finding of this study was that, despite the Ethiopian unilateral intervention inadequacy to deal with the problem of environmental degradation and water conservation in the Blue Nile Basin neither Ethiopia nor regional institutions like ENTRO attempted to shed light on the impacts of this problem if remained unaddressed. Moreover, Ethiopia and regional actors are void of designing a clear road map to overcome the cloud of mistrust and struggle to dominate the Nile water use which undermined hope for joint action against the common problem that jeopardize the interests of all the basin states. On the other hand the Ethiopian effort to safeguard the shared Nile water resource in the Blue Nile basin yield modest results it may encourage the basin countries to cooperate over the use and management of the Nile water. Hence, the inadequacy of Ethiopia's sole effort to conserve and protect the Upper Nile watershed calls for Ethiopian water management policy and water diplomacy to push for the collaboration of the downstream states as the threats to the Nile water supply are common threats to all Nile basin states' national water security.

Declining cost of renewables and climate change curb the need for African hydropower expansion

Across continental Africa, more than 300 new hydropower projects are under consideration to meet the future energy demand that is expected based on the growing population and increasing energy access. Yet large uncertainties associated with hydroclimatic and socioeconomic changes challenge hydropower planning. In this work, we show that only 40 to 68% of the candidate hydropower capacity in Africa is economically attractive. By analyzing the African energy systems' development from 2020 to 2050 for different scenarios of energy demand, land-use change, and climate impacts on water availability, we find that wind and solar outcompete hydropower by 2030. An additional 1.8 to 4% increase in annual continental investment ensures reliability against future hydroclimatic variability. However, cooperation between countries is needed to overcome the divergent spatial distribution of investment costs and potential energy deficits.

Anthropogenic stressors compound climate impacts on inland lake dynamics: The case of Hamun Lakes

Inland lakes face unprecedented pressures from climatic and anthropogenic stresses, causing their recession and desiccation globally. Climate change is increasingly blamed for such environmental degradation, but in many regions, direct anthropogenic pressures compound, and sometimes supersede, climatic factors. This study examined a human-environmental system - the terminal Hamun Lakes on the Iran-Afghanistan border - that embodies amplified challenges of inland waters. Satellite and climatic data from 1984 to 2019 were fused, which documented that the Hamun Lakes lost 89% of their surface area between 1999 and 2001 (3809 km² versus 410 km²), coincident with a basin-wide, multi-year meteorological drought. The lakes continued to shrink afterwards and desiccated in 2012, despite the above-average precipitation in the upstream basin. Rapid growth in irrigated agricultural lands occurred in upstream Afghanistan in the recent decade, consuming water that otherwise would have fed the Hamun Lakes. Compounding upstream anthropogenic stressors, Iran began storing flood water that would have otherwise drained to the lakes, for urban and agricultural consumption in 2009. Results from a deep Learning model of Hamun Lakes' dynamics indicate that the average lakes' surface area from 2010 to 2019 would have been 2.5 times larger without increasing anthropogenic stresses across the basin. The Hamun Lakes' desiccation had major socio-environmental consequences, including loss of livelihood, out-migration, dust-storms, and loss of important species in the region.

Realizing the full reservoir operation potential during the 2020 Yangtze river floods

Five severe floods occurred in the Yangtze River Basin, China, between July and August 2020, and the Three Gorges Reservoir (TGR) located in the middle Yangtze River experienced the highest inflow since construction. The world’s largest cascade-reservoir group, which counts for 22 cascade reservoirs in the upper Yangtze River, cooperated in real time to control floods. The cooperation prevented evacuation of 600,000 people and extensive inundations of farmlands and aquacultural areas. In addition, no water spillage occurred during the flood control period, resulting in a world-record annual output of the TGR hydropower station. This work describes decision making challenges in the cooperation of super large reservoir groups based on a case-study, controlling the 4th and 5th floods (from Aug-14 to Aug-22), the efforts of technicians, multi-departments, and the state, and reflects on these. To realize the full potential of reservoir operation for the Yangtze River Basin and other basins with large reservoir groups globally, we suggest: (i) improve flood forecast accuracy with a long leading time; (ii) strengthen and further develop ongoing research on reservoir group cooperation; and (iii) improve and implement institutional mechanisms for coordinated operation of large reservoir groups.

Collaborative management of the Grand Ethiopian Renaissance Dam increases economic benefits and resilience

The landscape of water infrastructure in the Nile Basin is changing with the construction of the Grand Ethiopian Renaissance Dam. Although this dam could improve electricity supply in Ethiopia and its neighbors, there is a lack of consensus between Ethiopia, Sudan, and Egypt on the dam operation. We introduce a new modeling framework that simulates the Nile River System and Egypt's macroeconomy, with dynamic feedbacks between the river system and the macroeconomy. Because the two systems "coevolve" throughout multi-year simulations, we term this a "coevolutionary" modeling framework. The framework is used to demonstrate that a coordinated operating strategy could allow the Grand Ethiopian Renaissance Dam to help meet water demands in Egypt during periods of water scarcity and increase hydropower generation and storage in Ethiopia during high flows. Here we show the hydrological and macroeconomic performance of this coordinated strategy compared to a strategy that resembles a recent draft proposal for the operation of the dam discussed in Washington DC.

Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological Characterization

The Lake Tana Basin, comprising the largest natural lake in Ethiopia, is the source and the uppermost part of the Upper Blue Nile Basin. In this review paper, research papers, mainly on the rainfall-runoff modeling and lake water balance, and on the hydrogeology, have been reviewed. The earlier water balance estimation attempts used simple conceptual and statistical approaches and calculate on a monthly timescale. More recent research has been using advanced semi-physically or physically based distributed hydrological models. Accordingly, mean annual precipitation over the lake was estimated in the range 36.1–53.1%; lake evaporation at 45.3–57.5%; river inflow (all gauged and estimated ungauged) at 43.6–63.9%; and river (lake) water outflow at 0–9.2%. With the few isotope studies, groundwater inflow and outflow are found insignificant. Different studies had estimated groundwater recharge, ranging from 57 mm to 850 mm. The basin has a heterogenous aquifer system consisting of different volcanic rocks and alluvio-lacustrine sediments. Generally, groundwater with low TDS, Ca–Mg–HCO3 type, isotopically relatively enriched, and high TDS, Na–HCO3 type, isotopically relatively depleted, water types have been identified. In this paper, major research gaps such as aquifer hydraulic characterization, surface-groundwater interaction, groundwater flow and groundwater balance have been identified. Hence, future research shall focus on the groundwater resources, so that existing surface water studies are updated and future water usage options are explored.

Evaluating Vulnerability of Central Asian Water Resources under Uncertain Climate and Development Conditions: The Case of the Ili-Balkhash Basin

The Ili-Balkhash basin (IBB) is considered a key region for agricultural development and international transport as part of China’s Belt and Road Initiative (BRI). The IBB is exemplary for the combined challenge of climate change and shifts in water supply and demand in transboundary Central Asian closed basins. To quantify future vulnerability of the IBB to these changes, we employ a scenario-neutral bottom-up approach with a coupled hydrological-water resource modelling set-up on the RiverWare modelling platform. This study focuses on reliability of environmental flows under historical hydro-climatic variability, future hydro-climatic change and upstream water demand development. The results suggest that the IBB is historically vulnerable to environmental shortages, and any increase in water consumption will increase frequency and intensity of shortages. Increases in precipitation and temperature improve reliability of flows downstream, along with water demand reductions upstream and downstream. Of the demand scenarios assessed, extensive water saving is most robust to climate change. However, the results emphasize the competition for water resources among up- and downstream users and between sectors in the lower Ili, underlining the importance of transboundary water management to mitigate cross-border impacts. The modelling tool and outcomes may aid decision-making under the uncertain future in the basin.

Would Africa's largest hydropower dam have profound environmental impacts?

In the face of rapid growth in the global demands for water, energy, and food, building large dams is expected to continue. Due to its potential opportunities and risks for the people of the Eastern Nile Basin, the Grand Ethiopian Renaissance Dam (GERD) on the Nile River has commanded regional and international attention. Once completed, it will rank the largest hydropower dam in Africa and among the largest worldwide. Discourse among scientists and negotiators from Ethiopia, Sudan, and Egypt on the design, initial filling, and long-term operation of the GERD is ongoing since the construction started in 2011, but no agreement has yet been reached. The discourse has hitherto focused on the impacts on hydropower production, water availability, and irrigated agriculture, with little attention to the dam's potential environmental impacts. Here, we communicate our viewpoint on this gap, drawing on knowledge from other dams around the world and some GERD characteristics. The hydrological alterations associated with the GERD could adversely impact fish, aquatic plants, and biodiversity in the downstream due to possible changes in water temperature, salinity, and oxygen content. The GERD's expected flooded area, location at low latitude in the tropics, and the deep turbine intakes could intensify greenhouse gas emissions, whereas the dam's high reservoir depth would abate the emissions. The dam's electricity could also reduce regional greenhouse gas emissions if combined with cleaner intermittent solar and wind energy sources. With a maximum reservoir area of 1904 km², surface evaporation and consequently local extreme precipitation and humidity could increase. The aforementioned impacts could have transboundary ecological, agricultural, and health implications and, therefore, should be taken into consideration alongside the benefits of the dam.

Understanding and managing new risks on the Nile with the Grand Ethiopian Renaissance Dam

When construction of the Grand Ethiopian Renaissance Dam (GERD) is completed, the Nile will have two of the world’s largest dams—the High Aswan Dam (HAD) and the GERD—in two different countries (Egypt and Ethiopia). There is not yet agreement on how these dams will operate to manage scarce water resources. We elucidate the potential risks and opportunities to Egypt, Sudan and Ethiopia by simulating the filling period of the reservoir; a new normal period after the reservoir fills; and a severe multi-year drought after the filling. Our analysis illustrates how during filling the HAD reservoir could fall to levels not seen in recent decades, although the risk of water shortage in Egypt is relatively low. The new normal will benefit Ethiopia and Sudan without significantly affecting water users in Egypt. Management of multi-year droughts will require careful coordination if risks of harmful impacts are to be minimized.

Several dams and reservoirs exist along the Nile, most notably the HAD (Egypt) and GERD (Ethiopia) dams. Due to the lack of strategies, the authors here explore potential risks and solutions how to use both dams simultaneously.