| South America


Left: Itaipu Hydroelectric Dam is located on the Paraná River between Brazil and Paraguay


As the authors conclude, high model agreement


across different scenarios enhances the reliability of their projections, making the study a valuable resource for developing climate adaptation strategies, particularly in possible high-impact regions like northern Argentina, the La Plata Basin, and eastern Brazil.


Bolivian insights The impacts of climate change on the hydropower


potential of a multipurpose storage system in the Bolivian Andes have also been the focal point of a recent study, this time in the Journal of Hydrology. Over the last decade, Bolivia has expanded its


hydropower capacity to meet domestic demand and explore export potential to neighbouring countries. And, according to the IHA, the Bolivian hydropower sector is ‘growing significantly’ and was listed as one of the top ten countries ranked by total installed hydropower capacity across South America, with 759MW in 2024. As Flores et al discuss in their research, Bolivia faces many challenges from climate change in water resources management and energy production. This study assessed climate-related impacts on river flows in the Rio Grande basin, and the hydropower potential of the Rositas multipurpose project’s proposed 600MW dam.


Considered a key project in the Bolivian National Agenda towards sustainability, Rositas hydropower dam also aims to expand agricultural land and mitigate downstream flooding in the Rio Grande basin. With the Rio Grande basin exhibiting ‘complex hydrological processes linked to mountain climate dynamics’, the authors evaluated the climate resilience of the project by analysing changes in its hydropower potential. By providing robust climate impact analysis, Flores et al believe their study will support key water and energy stakeholders in developing adaptation strategies to address projected hydrological changes. Using regional climate models from the Coordinated Regional Climate Downscaling Experiment (CORDEX) for the near (2040–2069) and far (2070–2099) future, river flow impacts were analysed under three future scenarios. Clustering was applied to 101 stations with similar climatic features to perform statistical downscaling at the catchment scale. The hydrological models SWAT+ and HEC-HMS were used to estimate changes in water availability and hydropower potential. Projections indicate that river discharges will increase in the wet season and decrease in the dry season,


exacerbating the severity of droughts. While annual hydropower potential increases by up to 11% in the near future and 9% for the far future, seasonal variations are significant. Energy potential decreases by up to 30% in June to September but increases by up to 25% in November to February. The authors say these results highlight climate risks faced by the Rositas project and the need for adaptative water management strategies to mitigate potential water conflicts. ‘Key implications include the need for revised


reservoir management strategies to address dry season energy shortfalls, as storage limitations may limit the full use of wet season inflows despite higher annual averages. These changes, coupled with increasing evapotranspiration, threaten water security,’ Flores et al warn, ‘and require adaptive reservoir management to balance energy production with competing agricultural and flood control needs. Hence, the Rositas project needs to incorporate climate-resilient designs to mitigate water scarcity and flood risks and ensure reliable energy and water supply for users.’ Providing a template for assessing climate risk in Andean hydropower projects, the authors believe their study highlights the need for seasonally adaptative infrastructure design. The projected hydrological shifts can be used to revise water allocation frameworks, while energy planners can explore complementary renewable energy such as solar to offset dry season deficits.


Integrating solar power A proposal to mitigate the intermittency of renewable


energy generation and address the limitations of water resources in the reservoirs of Andean regions, has studied integrating hydropower plants with solar and battery storage. The focal point of this study were five hydroelectric power plants on the Limay River in Argentina which collectively produce 12,830GWh annually, with an installed capacity of 3970MW and an overall capacity factor of 37%. As Dr Luis Juanico and Martin Ducos explain, these Andean hydroelectric dams were designed to operate continuously but their effective generation capacity is significantly constrained by the highly variable availability of water resources. This means there is significant idling capacity - ranging from 50% to 75%, or 12 to 18 hours daily -in both the power transformation system and the National Interconnected System transmission line, with generation further influenced by


www.waterpowermagazine.com | April 2026 | 13


Below: Severe dry weather in 2024 reduced Brazilian hydropower output to a three- year low. It is claimed the fear of future low flows has been a limiting factor in the development of new sites


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