Serious problems abound in the Río Cuervo dam's environmental impact assessment, calling into question its approval

The unfortunate environmental approval of the Río Cuervo dam on Tuesday in Chile’s southern region of Aysén was a clear sign that the government is willing to approve any large energy project regardless of the impacts it would have on nearby communities, local economies and the environment. The project’s woeful environmental impact assessment was full of major research gaps, poor data and deficient analyses. This 640 megawatt dam would be part of a larger, three-dam power plant called Energía Austral, which would have a total installed capacity of just over 1,100 megawatts and cost $3.077 billion dollars. The Río Cuervo dam is just the latest of several such projects to receive its environmental permit despite being so patently damaging and opposed by local citizens. Other recent examples include the Punta de Choros coal power plant*, the mammoth coal power plant called Castilla**, and, of course, the mega-dam complex HidroAysén. Instead of pushing for these massive conventional energy plants to meet future demand, Chile’s government should take advantage of its remarkable solar, geothermal and wind potential and support the growing renewable energy sector as well as enact more robust energy efficiency measures. Doing so would create a more modern, flexible and stable grid, and make Chile a world leader in clean energy growth.

Tuesday I described the two most glaring problems with the Río Cuervo dam proposal:  its location within the impact zone of the active Liquiñe-Ofqui fault line, and the fact that the company is submitting the different components of its hydroelectric plant for review separately, in effect fragmenting the review and preventing anyone from seeing the combined impacts of all three dams and the transmission line. Here is a list of the other major problems with the project’s environmental impact assessment, which is available here. (Many thanks to our Chilean partners for their excellent analysis of this long and labyrinthine document.)

  1. The EIA lacked a proper geological baseline. The measurements contained in the EIA were rarely consistent and quite superficial. The proponents did not test or measure the project site’s rock and ground soils to the appropriate depth recommended by state agencies, nor did they sufficiently assess the activity of the system of fault lines in the direct area as recommended in such a uniquely complex area. Without such data, it is impossible to conclude that this is a geologically sound place to build such a project.
  2. The EIA did not include sufficient data to qualify the nearby Maca Volcano as “inactive.” In the event of an eruption, 50 million cubic meters of debris would flow out of the Maca volcano and largely into the Río Cuervo dam’s reservoir, which would in turn be significantly impacted and potentially rupture. It’s worth noting that the Chaitén volcano, which erupted in 2008 is also listed as “inactive.”
  3. The project’s proponents presented no empirical data in its hydrological baseline about the Cuervo River’s hydrology, but based its study on extrapolations and assumptions. For a large dam being built on a major river, this is unacceptable.
  4. The EIA lacked data about the interaction of the different components of the project with the ecosystems as a whole. It also did not provide any environmental monitoring plans, which the state agencies requested.
  5. There was no analysis of the impacts of the dam on the local tourism industry. It’s worth noting that these energy projects – Río Cuervo and HidroAysén – have not evaluated how the new presence of large industry would impact the region’s image as a world-class tourism destination for rugged and pristine experiences, and therefore its tourism industry.
  6. The social and cultural impacts of the project were limited to descriptions of the temporary workers who would come during construction. The analysis did not include any details about how the company would mitigate negative effects of this “floating population” of workers on the small town of Puerto Aysén and its neighbors.
  7. The EIA’s evaluation of the dam’s potential impacts on local fauna was severely deficient and lacked any evidence of certainty. Throughout the document, effects were described in the conditional tense – that is, “it could do this,” or “it is possible that the project could do that.” Such language is hardly indicative of an adequate understanding of environmental impacts to warrant approval.
  8. The EIA also did not meet standards for a proper analysis of the impacts on special wilderness areas, including wetlands and the biological corridor of endangered species. In particular the Huillín (or Southern River Otter), an IUCN endangered species, is highly sensitive to changes in its habitat, and has been identified as living within the project’s baseline.
  9. The productivity of coastal waters would diminish as the river’s nutrients and silica loads that currently flow to the fjords and then to the Pacific Ocean would be cut off and/or seriously lessened by the dam. Such a situation occurred further north in Chile: the Ralco Dam on the Biobío River caused lower biological productivity in the waters of the nearby coastal waters.
  10. The maps used by the proponents in the study were at inappropriate scales, making it difficult to correctly estimate effects of the project.

It is plain, then, that the Río Cuervo dam as presented in its EIA documents should not have been approved – there are just too many unanswered questions and unaddressed fundamental issues to allow this project to move forward. Unfortunately, the citizens of Puerto Aysén would be the first to deal with the consequences of any failure of the dam – which is not out of the question based on the dam’s location.

Fortunately, there are still many ways to stop the Energía Austral dam complex from going forward – legal challenges and appeals to Río Cuervo, and, of course, the reviews of the other two dams and the transmission line. In the meantime, let’s hope the government will see that renewables and efficiency are far better options to meet Chile’s future energy needs, and these dinosaur hydroelectric plants in planned for Patagonia will be a thing of the past.


*The Punta de Choros received its environmental approval from the regional authorities, but President Piñera soon intervened and stopped the plant from going forward as planned.

**The 2,100 MW coal plant Castilla was approved in February 2011, but is currently stalled due to legal challenges in the Supreme Court.