This content was originally published on The Resilience Shift website. The Resilience Shift, a 5-year programme supported by Lloyd’s Register Foundation and hosted by Arup, transitioned at the end of 2021 to become Resilience Rising. You can read more about The Resilience Shift’s journey and the transition to Resilience Rising here.

The Resilience Shift wants to share good work by others. This new case study features one of the world’s largest hydroelectric dams, Itaipú Dam, and the natural ecosystems that regenerate its surroundings and increase its resilience to climate change.

South America’s most efficient hydropower plant owes a lot of its success to the trees that line the banks of the Paraná river. Itaipú Dam is also one of the world’s largest generators of renewable energy, and supplies up to 16% of Brazil’s electricity supply, and 90% of Paraguay’s. The dam’s operator Itaipú Binacional, put sustainable development at the heart of their vision for the dam. They took a whole-system approach, investing in conservation and tree planting projects that improve the quality of the water that flows into the dam. 40 years on the environmental projects have provided an estimated $45,000,000 in direct benefits alone.

CBA numbersA new case study, produced by Acclimatise for The Resilience Shift, describes how the reforestation of native trees is crucial to the smooth operation of the dam, as well as helping improve its resilience to climate change and saving on maintenance costs.

Itaipú Binacional has recognised early on that a healthy watershed is integral to the dam’s operations and to the well-being of the communities along the Paraná river. In the 1970’s Itaipú pioneered a series of watershed restoration programs, and in 2015, Itaipú Binacional received UN-Water’s Water for Life Award for best practices in water management. By protecting the forest, re-foresting other sections, and improving land management practices, they were able to create a long-term solution to securing a reliable and low-sediment flow of water.

Sediment flow into rivers can block dams and affects dam safety, storage and discharge capacity, reduces energy production potential, and flood attenuation capabilities. An increase in sediment is related to deforestation for agriculture and poor land management practices which cause soil exposure and erosion. Deforestation also affects the speed of water run-off into the river, increasing peak flows during the rainy season and reducing river flows during the dry season. In planting trees in the river’s watershed, Itaipú has create a giant water filter. These filtering forests help to stabilise the soil, reducing the amount of sediment that flows into it.

Demonstrating the highly interconnected nature of infrastructure systems, Itaipú Binacional’s efforts include planting over 44 million trees in the company-owned area around the dam, reforesting, restoring, and conserving 101,000 ha of land and 421 micro-watersheds, and restoring 1,600 km of rural roads.1

Recently, other programmes have expanded the dam’s work in improving water quality in the Paraná watershed whilst also achieving a broad range of social and environmental goals. For example, Cultivating Good Water was a 15-year project targeting land-based activities that are detrimental to water quality and flows. The project worked with many partners to deliver education, technical assistance, technological innovation, and employment opportunities to local communities. For example, building permeable roads has the dual benefit of slowing water flow in heavy rain and diverting it to be filtered through the soil, whilst also preventing the roads from becoming flooded and cutting off emergency access to communities.

Waste management diagram

Though the Cultivating Good Water project finished in 2017, due to the sustainable structure of the projects and the ongoing service that nature-based solutions provide, the project continues to contribute towards food security, poverty alleviation, improved health and sanitation, climate change mitigations and adaptation, and biodiversity support. This is particularly valuable when systemic shocks, such as COVID-19, alter the way human systems operate – ecosystem services continue to function.

Read the case study or download the document.

1 Itaipú Binacional. 2020. Frequently Asked Questions. Available at, https://www.Itaipú