As Julia, the local woman we visited on our last morning on the Baker stated, this past summer in Patagonia has been exceptionally rainy. People told me that every single day of the summer months was wet and cold except for two. Which is why we so relished those few moments of sunshine we saw each day on the River. It is also why the water level of the Baker was unusually high during our trip. At least once a day Brian commented on this fact, pointing out small, flowing channels that typically are dry, or the surprising height of the water level among the flora on the river banks.
channels and wetlands in the foreground were products of the summer's rain
Given the fact that the water level when we were there was very nearly as high as it’s been in years, how can you explain this photo?:
How did that tree get deposited on top of that boulder?
A GLOF did it.
A GLOF – a glacial lake outburst flood (or jökulhlaup, the Icelandic term that is also often used). Let me explain:
A GLOF occurs when water increasingly builds up behind an obstacle, such as a glacier, to the point of bursting through or over this obstacle and flooding downstream in a massive rush. (Here is a more thorough description). GLOFs are well-documented phenomena around the world (from Asia to Iceland, the U.S. to New Zealand), and are increasingly becoming an issue here in Patagonia, where much of the area’s fresh water depends on the steady melt of Chile’s remarkable quantity of glaciers. A recent NASA study showed that these glaciers are melting at faster rates than ever before, which some researchers attribute to climate change. As a result, after nearly 40 GLOF-less years, the Baker and its tributaries—specifically the Colonia River—have seen six substantial GLOFs in the past 2 years.*
One key reason I joined this research group on their Baker trip was to learn more about these hydrological events and see first-hand some of the jökulhlaups’ effects on the River. And who better to show me than this team: Brian, our boat captain and the Limnologist (a scientist who studies fresh water) who makes this trip monthly, taking detailed notes and water samples each time; Andy, a Ph.D. candidate in Geomorphology, who has a knack for explaining complicated hydrological processes in a very understandable way; and Nicolas, the Chilean journalist whose local knowledge was so helpful, and who (thankfully) asked almost as many scientific questions of the other two as I did.
Brian pointed out evidence of the last GLOF as we rowed down the Baker, such as the tree in the above photo (we saw several similar sights, in fact). He also often put the phenomenon in context, as you can see in this photo, where, during a recent GLOF, the flood levels reached as high as the square blue box to the left of the river crossing apparatus.
Why are GLOFs important to our Patagonia BioGem campaign? These floods can be quite destructive to anything downstream, natural or man-made – such as dams. They could potentially damage the proposed dams themselves, and they could affect the dams’ operation capacity and longevity by flooding the reservoirs with more sediment than they were designed to handle. Logically then, HidroAysén’s two proposed dams on the Baker River could be compromised by the increased incidence of jökulhlaups, and the company should be worried about these events.
Yet their environmental impact assessment (EIA) and its Addenda do not provide nearly enough solid scientific or technical data to prove that they have thoroughly considered these risks in their plans and designs. During the last round of comments on the EIA’s Addenda, multiple government agencies specifically noted that HidroAysén’s data about GLOFs was highly inadequate, requesting more and better information (all official documents in HidroAysén’s environmental review process are available in Spanish here).
Each time I saw evidence of the recent Colonia and Baker River GLOFs while on this trip, I was again reminded of the unpredictable power of this river system, often belied by its placid surface. It was clear to me that GLOFs pose a serious threat to HidroAysén’s proposed—and unnecessary—hydroelectric center, heightening the risks of building and investing in this scheme. Clearly, these phenomena are important to our campaign. Very, very important, in fact.
And they should be important to HidroAysén. Very, very important, in fact. To date, however, the company has treated this topic as a peripheral nuisance, underscoring yet again why their proposal simply should not be approved.
*As this article was published in November 2009, its research does not include the most recent GLOF in January 2010.