The Clinic | Maipo River Wetland Management warns of risks following approval of San Antonio Port expansion: it could affect the ecosystem and compromise its future
- Publicado el 27.05.2026
- Escrito por Angel Fondon
The Cosmos Foundation, which manages the Río Maipo Wetland Nature Sanctuary, outlined potential risks following the approval of the San Antonio Outer Port project by the Valparaíso Environmental Assessment Commission. Specifically, they warn of impacts on the coastline and the wetland ecosystem.
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After the Environmental Assessment Commission (Coeva) of Valparaíso approved the Environmental Qualification Resolution of the San Antonio Outer Port project, an expansion of the most important port structure in the country, the Río Maipo Wetland Nature Sanctuary expressed its concern at this milestone.
Although the unanimous approval was celebrated by the Government and at the regional level, the sanctuary’s administration warned that it could have severe repercussions for the wetland, which is one of the largest in the country.
In a statement released jointly by the Cosmos Foundation—the official state administrator for the conservation of the Río Maipo Wetland Nature Sanctuary—they expressed their views. While acknowledging the importance of the San Antonio Outer Port project for the country’s port development, they asserted that “our position, throughout the entire environmental review process, has been that the Environmental Impact Study contains fundamental technical deficiencies that prevent a proper assessment of the breakwater’s effects on the Maipo River estuary, its ecosystem dynamics, and the specific impacts on the Sanctuary’s conservation targets.”
Along those lines, and in accordance with the approval of Coeva, they state that there is concern about the “impacts that the project will have on the coastal edge, the ecosystem functions and the conservation objectives of this protected area, considered one of the most important wetlands in the country.”
The risk to the wetland after the approval of the expansion of the Port of San Antonio
The environmental permitting process for the Puerto San Antonio project took six years to complete. The initiative was submitted to the Environmental Impact Assessment System in 2020, and since then, environmental organizations and the wetland’s management have expressed their concerns.
“Since its entry into the SEIA in April 2020, and due to serious technical shortcomings in the surveying of the environmental baseline, the project has accumulated almost 6,000 observations from public bodies and communities, reaching an Exceptional Addendum, a highly infrequent figure in the SEIA,” they emphasize at Fundación Cosmos.
Along with this, they claim: “After almost four years of suspension requested by the owner himself to respond to the observations, technical questions persist about the effects of the breakwater, due to its location and the processes of sand accretion and siltation at the mouth of the Maipo River; the ecosystem fragmentation between the Llolleo Lagoons system (Ojos de Mar) and the Maipo River Wetland; the impact on habitats of resident and migratory birds; and the impact on the conservation objectives and ecosystem functions of the Sanctuary, which are fundamental for the well-being and resilience of the surrounding communities.”
Now, the administration will review the technical and legal background following the Coeva resolution. This is in order to identify the actions to be taken to ensure the conservation of the Maipo River Wetland. “Protecting the Sanctuary requires a rigorous review of an environmental decision whose effects could compromise the ecological and social integrity of a strategic ecosystem for the central coast,” they emphasize in the statement.