Rocuant-Andalién wetland in Talcahuano, within the Biobío region. Photo by Sydney Walsh/Audubon.
In 2024, storms left parts of the Biobío region under waist-deep water, damaging more than 2,000 homes as rivers burst their banks. A new assessment from the Nature-Based Infrastructure (NBI) Global Resource Centre shows that restoring local wetlands could prevent millions in flood damages, generating a net benefit of more than USD 42 million. If implemented in time, every dollar invested would return about USD 1.30 in value.
The new study examined the Rocuant-Andalién wetland system, which once served as a natural barrier against flooding but has been heavily degraded by urban expansion, industry, and pollution. The Americas Flyways Initiative (AFI), a partnership led by Audubon, BirdLife International, and the Development Bank of Latin America and the Caribbean (CAF), is designing a project to restore strategic areas of the wetlands system across the Andalién, Carriel Norte, and Vasco da Gama sites. The goal is to reduce direct flood risks for more than 10,000 people while restoring biodiversity and supporting local communities.
To assess the full impact of the restoration, the NBI Centre applied its Sustainable Asset Valuation (SAVi) model. SAVi generates an integrated cost-benefit analysis that goes beyond traditional economic modelling by capturing social, environmental, and climate risks. It compares business-as-usual scenarios, in which wetlands continue to degrade, with restoration scenarios that bring them back to function.
Signage created for a coastal stewardship project with local students at the Rocuant-Andalién wetland. Photo by Sydney Walsh/Audubon.
The analysis projects that over 26 years, restoration would generate a net gain of USD 42 million. In addition to avoiding flood damages, healthier wetlands would increase property values, reduce income losses when floods disrupt livelihoods, and create opportunities for recreation and tourism. Wetlands become even more valuable under high-risk climate scenarios, when extreme rainfall and flooding events are more frequent. Flood damages avoided could reach nearly USD 59 million.
“According to AFI’s estimates, restoring the Rocuant-Andalién wetland—an area of great importance for migratory birds—would help reduce flood risk across more than 290 hectares of the greater Concepción area and its surroundings. Investing in the health of these ecosystems protects communities from natural disasters, such as floods and tsunamis, while supporting the conservation of the biodiversity that sustains life in the region,” said Santiago Aparicio, director at the AFI.
Lesser yellowlegs (left) and black-necked stilt at Rocuant-Andalién wetland in Talcahuano, within the Biobío region of Chile. Photo by Sydney Walsh/Audubon.
While the project remains in the planning stage, the numbers support calls for integrating nature-based infrastructure into Chile’s adaptation strategies. For the CAF, the analysis demonstrates that ecological restoration can perform as well as, or better than, traditional grey infrastructure when wider benefits are considered.
Chile’s wetlands are under pressure, and their degradation has increased the vulnerability of communities across the Biobío. The proposed restoration shows how these ecosystems could once again act as natural coastal protection while also contributing to social and economic development. The challenge now is to move from assessment to implementation before further losses occur.
