Tuesday, July 10, 2007

Quick Hit: Mixed News from South America

Thanks to Jon Sealy who reports from his web-log on a BBC story about Brazil's giving the green light to the construction of two dams along the Amazon's largest tributary, the Madeira River.

Good news: it's for hydroelectric (that is, relatively clean energy) for Brazil's expanding energy needs. Bad news, from the article: "The river is said to have one of the most diverse fish stocks in the world."

Plus there's the inevitable failing of all dams due to sediment. Sheesh. Good luck, Amazon.

3 comments:

MBQ said...

I have a problem figuring out exactly what I think of dams as objects that do exist and will continue to exist. On the one hand, I see the damage they do to the ecosystem, but on the other I do see the benefit they provide - clean water, clean energy - and can understand why people who need both would choose that over a diverse fish stock. We can't eliminate dams, so what we're left with is trying to make them as ecologically sound as possible.

Of course, I'd prefer people don't live in areas that can't sustain the population.

Tommbert said...

There's a crazy idea--sustainable population.

You're right we can't get rid of them. Some estimates for getting rid of Glen Canyon Dam (GCD), one of the most contested domestic dams, run as high as 300 billion. With a B, billion. That's why it made it a lot easier for the GCD Adaptive Management Plan to choose regulating flow of the Colorado through that canyon more in accordance with what is more ecologically sound, based on sedimentation, fisheries, rainfall, and other kinds of research. It was just cheaper to make things work. (Not that they had even considered getting rid of dam in the first place; this just made it easy for them to point out, that since it would be too expensive to get rid of it, why not regulate it better.)

But that's the funny part about regulation of resources like forests and rivers and what not (yes, there's some McKibben-esque sentiment in here). When the Adaptive Management Program put its list of regulation choices together, some 16 options, it discounted 3 out of the gate. One of those three was trying to recreate historical flows (that is, pre-dam) that had been charted since the 1910s. They deemed the pre-dam version unusable because research showed that they could better manage the river with the calculated flows from river researchers. It's a case where humans think they know better than the river does. I'm not saying they don't (they could, for all I know). But the river managed itself fine for years--meaning water came in upstream and left downstream. It still does that, but river managers think that tinkering with it will work better.

I've for a long time been of the opinion that if it ain't broke, don't fix it. I mean, why discount the pre-dam flows at all? The running average, according to their own data, shows a steady average in the river before the dam, and a screwed up, inconsistent flow after significant damming. If anything (if it is broke and needs to be fixed), it's broke because the human managers changed it.

So why dump the original data? Water would still come and go, power would still be generated, and the recreation resources would be maintained. At the very least, they could have spent some time with the data instead of just saying, "Actually, that's no good," not too far off of the original two sentence rejection of the option in the GCD Adaptive Management Plan's Environmental Impact Statement from 1996. The point is this: if you can have the same resources generated, why not try and keep things more in line with extant ecological models?

The same thing applies here that you mention. If LA needs power, why are we sending it all the way from eastern Arizona? Because LA is an unsustainable locale for the number of people there. But I digress.

MBQ said...

I'm all for sustainable population as a model for population growth, but I have the same reaction now as I did the first time I encountered it back when we read Kirkpatrick Sale's Dwellars in the Land - people will never go along with it. People in LA won't want to be told to move to Nevada, and people who live in Nevada (Nevadans? Nevadians? Nevadeans?) likely don't want them anyway. (Though people more concerned with economic development surely would.)

That's not to dismiss the idea, of course, but merely that it's going to have to ferment at the theoretical stage for a long, long time before it ever becomes a viable option in this country.

On dams - even if the data says any river has been consistent for 20 years, 50 years, 100 years, the pro-dam contingent will argue that we can't depend on that consistency long-term. They'll always be able to point to an inconstent season/year as a fear tactic.