Quantity over Quality: HidroAysén proves yet again why its mega-dam proposal should not be approved

HidroAysén, the company behind the plan to build five mega-dams on two of Patagonia’s most pristine, wild rivers, has proven again why its proposal should not be approved.  Several times over the past year and a half the company has had the opportunity to produce a good, quality report about the environmental impacts of its project and justify its construction.   In each instance they had all the benefits of time and resources on their side.  And each time the planning, research and information HidroAysén submitted was found insufficient to warrant approval from the government agencies.  

The first example was in August 2008, when HidroAysén submitted its nearly 11,000-page environmental impact assessment (referred to more simply as an EIA) of the mega-dam project.  The involved state agencies and the public alike criticized the document for its wide variety of deficiencies.  Then in July 2009, the Patagonia Defense Council (CDP) of which NRDC is a member, released a study proving that there is simply no need for any of the 2750 MW that HidroAysén’s hydroelectric power plant would produce (for more details about the report’s findings, see Allie Silverman’s blog).  Yet the company made no attempt to disprove the findings or claim otherwise.

Most recently, on October 20th, HidroAysén submitted its Addenda, which is the term used for the document with the company’s answers to the agencies’ prior observations about the EIA in 2008.  It also contained new scientific and technical studies that have been conducted since last year’s review, and numerous maps.  With just 15 days to review the 5000-page Addenda, 29 of the 32 state agencies again found it insufficient, with 14 of the agencies making highly critical comments. 

To be clear, the company had nine months to prepare this document.  Then it requested and was granted two more.  And it could have requested even more time to ensure that its work was done thoroughly and correctly.  Instead, HidroAysén took the “quantity over quality” route, delivering an enormous document that the agencies said lacks crucial information, ignores important issues, uses incomplete data, misidentifies scientific facts and provides shoddy analyses.

Presently, the Aysén region’s environmental commission (COREMA) is reviewing the agencies’ latest comments, and is deciding whether to reject the project, approve it, or ask HidroAysén to address the new observations (you can read a more thorough explanation of the review process here).  While this last option seems to be the most likely outcome at this point, I think it is worthwhile to describe some of the reasons why HidroAysén’s EIA and Addenda should be rejected outright.

What the Addenda are lacking

In reviewing the observations made by the state agencies, several key themes emerge, recur, and often overlap, highlighting the document’s underlying flaws.

  • First, HidroAysén’s information clearly does not value Patagonia as the unique resource that it is, ignoring the irrevocable damage the dams and the power lines will do to this pristine, remarkable place and the wildlife living there.  Thirteen of the agencies commented that the Addenda does not address the effects the dams would have on the region’s landscape, tourism industry, flora and fauna, aesthetic qualities or biodiversity.  The National Forestry Corporation (CONAF) specifically questioned the impacts that flooding would have on Patagonia’s protected species, such as the Huemul.  The Tourism Service (SERNATUR) stated that the dams’ profound impact on the landscape will affect tourism throughout the entire Patagonia – not just the Aysén Region – and therefore they should be evaluated on the national level.


  • Second, the document is woefully lacking in its analysis of the effects of climate change on Patagonia’s glaciers, which are documented to be melting at alarmingly rates.  Three of the most critical agencies, CONAF, the Water Authority (DGA) and the Geological Service (SERNAGEOMIN), all recognized that the impacts of climate change as they relate to dam safety have not been properly evaluated. 

    One specific effect is a glacial lake outburst flood, or GLOF (also called a jökulhlaup) which is the sudden release of impounded water (a more thorough description is available here).  GLOFs can be destructive and dangerous, and can unpredictably alter river flow.  Since April 2008, five similar GLOFs have occurred on the Colonia River, a major tributary to the Baker River (one of the two rivers HidroAysén proposes to dam).  Yet the sections in the Addenda about these phenomena (specifically the hydrology and hydrogeology annexes) use data that is incomplete, out-dated or not publically available.


  • Third, the Addenda’s scientific analyses and its maps are insufficient, flawed or just plain incorrect.  For example, SERNAGEOMIN and DGA both noted that the maps HidroAysén provided are not detailed enough, use an inappropriately large scale, or do not show the relevant areas—such as the regions that will be flooded.  The Tourism Service (SERNATUR) also observed that the maps are inadequate to evaluate the impacts flooding will have on the tourism industry.

    As mentioned above, the hydrological analyses are inadequate.  In addition, SERNAGEOMIN requested to see HidroAysén’s baseline geological study, because the company may have misidentified the area’s rock, mistaking it for another type that is affected differently by high water pressure.


  • Fourth, the flooding areas would violate Chilean environmental law.  On this point, CONAF was the most vocal agency, supported by similar comments from the Ministry of National Property.  They pointed out that the dams would flood parts of Laguna San Rafael National Park.  This would violate Chile’s longstanding Forestry Law (established in 1931), the Washington Convention (which Chile incorporated into national law in 1967), and the park’s status as a UNESCO Biosphere Reserve (designated in 1979).


  • Fifth, the Addenda contain such a large amount of new information – much of which is highly technical or scientific – that requiring the agencies to thoroughly review it in just 15 days is unfair.  In their submissions, both SERNAGEOMIN and DGA specifically commented on the short review period, given the task at hand.  Furthermore, DGA noted that the Addenda expand the flooding area enough beyond what was described in the EIA that the public should have the opportunity to comment on it.  This underscores another important problem with the process…


  • Sixth, there was no opportunity for the public to comment on the Addenda.  During the initial review of the EIA, the public had 60 days to submit comments to COREMA.  After that, there was no official time when the public can participate in the process.  This stands in stark contrast to standards set by international bodies like the World Bank, and even Chile’s own law (Section 1, Article 4), which declares that “It is the State’s duty to facilitate public participation (Es deber del Estado facilitar la participación ciudadana).”


This is just a brief summary of the Addenda’s most blaring omissions and faults; the agencies provided many others (for the ambitious researcher, all documents are available here).  What is evident is that HidroAysén had all the advantages of time and resources to create a thorough, high-quality EIA.  What it has submitted (twice, now) was a mountain of paper that is anything but. 

About the Authors

Amanda Maxwell

Director, Latin America Project

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