The 2075MW Cahora Bassa South Bank hydropower project in Mozambique has achieved Silver certification under the Hydropower Sustainability Standard (HSS).
Owned and operated by Hidroeléctrica de Cahora Bassa (HCB), the project is located on the Zambezi River in Tete Province and generates an average of more than 15,000GWh annually. Construction began in 1969 and commercial operations started in 1977.
Cahora Bassa is the second hydropower project in Africa to secure HSS certification, following the Ngonye Falls project in Zambia in 2024. Several other projects across the continent are now progressing towards certification.
The achievement follows almost a decade of work by HCB to improve the project’s sustainability performance. Cahora Bassa was first assessed in 2018 under the Hydropower Sustainability Assessment Protocol, a predecessor to the HSS, establishing a baseline and identifying areas for improvement.
Measures introduced following that assessment include a climate resilience assessment and risk management plan, a reservoir inflow forecasting system, a greenhouse gas emissions assessment using the G-res Tool and a new biodiversity management plan. HCB has also formalised its support for the neighbouring Mágoè National Park.
A further assessment under the HSS in 2025 found that Cahora Bassa had improved its sustainability performance beyond the minimum certification requirements. The project recorded strong performance in worker health and safety, water quality monitoring, hydrological management, climate change and stakeholder engagement.
The assessment also identified opportunities for further improvement, including greater integration of environmental and social management systems, expanded biodiversity monitoring and strengthened emergency preparedness. HCB said these areas are being addressed through its sustainability action plans.
“Overall, the biggest change has been the transition from managing sustainability as a set of individual actions to a more structured and integrated approach, supported by stronger systems, clearer priorities and continuous improvement,” said Nico Savaio, ESG and Integrated Management System Coordinator at HCB.
“Achieving certification was a significant milestone for the entire HCB team because it recognised years of dedication, collaboration and continuous improvement,” Savaio added.
“Perhaps most importantly, the certification is not seen as the end of the journey, but as a milestone that motivates us to continue improving.”
João Costa, Executive Director of the Hydropower Sustainability Alliance (HSA), said the certification demonstrated how older hydropower assets can adapt to current sustainability expectations.
“Cahora Bassa sends an important message to the hydropower sector. A project built more than half a century ago can continue to evolve and meet the sustainability expectations we set today.
“HCB has shown the value of engaging openly with independent assessment, acting on the findings and making continuous improvement part of how a project is managed. We hope this achievement will inspire other operators across Africa and beyond to follow the same path.”
