This is a pretty random opener so bear with me. I was browsing deeply through Wikipedia last week and ended up on the page for the year 2012. Sounds like it'll be a good time (presidential election, London Olympics, end of the world according to the Mayan calendar and two key dam removals in the U.S.). So let's assume the world doesn't end, what's the next most exciting prospect for the not-too-distant future? Olympics? Yawn. Politics? I'm still overdosing from this year. If you guessed dam removal, then get excited, because you're right. Why is knocking down a concrete wall something worth celebrating? Because a lot of dams in the U.S. do nothing but wreak havoc on the upstream ecosystems, starting with the fishing and trickling down (or upstream in this case) all the way to tree growth.
The two dams slated for destruction are the Glines Canyon and Elwha dams, both on the Elwha River in northwest Washington. They were built in the early part of last century and didn't have any facilities to help fish swim upstream. Those fish were migratory salmon who were cut off from their spawning grounds. No place to get it on meant no eggs in the stream and no returning salmon. And after a salmon lays eggs it dies. The decaying carcasses would add nutrients to the riverbank soil, improving the health of trees and forest vegetation.
The benefits list of dam removal goes on and on, so click on over to read about them.
Most importantly, when a dam is removed it creates a seamless connection of seasonal fish habitat. Salmon aren't alone in river migration. On the East Coast, the Army Corps of Engineers wiped out a dam in Fredericksburg, Va., so that shad and striped bass could reinstate their migratory routes. Trout and smallmouth bass will also travel long distances in a river to reproduce.
Probably the second most important facet of dam destruction is the even deposit of sediment and silt. With a dam in the way, all of the stuff a river picks up and moves in its current gets blocked by the wall. With an even flow those minerals, sands and soils will be left evenly on the riverbank.
Next up, a flowing river has stabilized dissolved oxygen levels. This is important but not a very sexy talking point. Basically it means better water quality for sensitive fish such as trout.
Finally, water clarity and normalized temperatures return to a river when it's let go to a natural state. That again means more biological diversity and healthier conditions for the river and surrounding lands.
Let's hope 2012 is the kickoff of a new movement to dump the dams. That is, of course, if the apocalyptic doom predicted in the Mayan calendar doesn't come to pass.
