Rivers are the life-blood of human civilization. They have provided transportation routes, food, and most importantly FRESH WATER to people since the earliest times. Recently, we humans have begun to manipulate these natural marvels into something they originally were not.
Dams have been build for different reasons, but they all do the same thing...They block the flow of the river., reducing the current and creating a reservoir of non-flowing water behind it. Don't start thinking, "Oh, this guy is just some damn tree hugging liberal, and he is just going to bash on dams and everything that humans do." Not true, well sorta not true. But this post is not about politics, so we wont go there. If you have questions about or want to discuss my politics, belief in God, or my baseball purist ideals, send me an email, lets go grab a beer and have a conversation. I would love to have a conversation about any of that.
Dams have been built to control flooding, provide power, and to secure an all important fresh water source. But there have been unintended detrimental consequences to these. Families have been misplaced, history has been destroyed, and species have been lost. This post isn't about the relocation of people or the loss of history, google that stuff if you want to learn about it. I am going to talk about how impeding the flow of a river can change the ecological make up of a river.
Species, not only fish, thrive in the ecosystem they were created and evolved for. As I discussed in The Plight of the Guadalupe Bass, species of fish such as the Guadalupe Bass are made for life in flowing water. When you build dams and stop the current of the river, the habitat for these species is reduced. Species such as Striped Bass, Sturgeon, Salmon, and Steelhead, are just a few other fishes that can be affected. On the San Marcos River, the American Eel and the Giant Fresh Water Prawn are not seen much anymore because of dams. Plant life, such as Texas Wild Rice, has also been adversely affected by the reduction in flowing water.
Beyond reducing the amount of flowing water in a river, dams also change the ecosystem of the waters in other ways. When you reduce the amount of flowing water, you increase the amount of stagnate "dead" water. These reservoirs can benefit certain species of plant and animal life. Unfortunately, these species are often non-native species, such as Hydrilla and Milfoil, that can reduce or even completely choke out native species. In the long run, fighting these invasive species of plants and animals costs the State Governments huge amounts of tax-payer money. Other effects of dams, such as the warming of waters behind the dam and cooling of water released below the dam, also hinder native species and promote non-native invasive plants and animals.
I am sure that there are other impacts of dams beyond what I discussed here. Do some research on your own and let me know what you learn. Sadly, many of the dams that were built in the past are no longer in use. They remain standing, not serving any purpose, and continue to affect the migrations of fish and change the habit of the rivers. There are organizations such as American Rivers, along with many others, that are working to remove these dams and restore the rivers to their natural state.
Positive and negative, like them or not, dams have an impact on the current of the rivers and ultimately on our lives. Do a little research, learn about them yourself, find out what you can do to help your local waters. If you have any questions, let me know, I might be able to point you to the answers. I am always excited to hear your thoughts and discuss these issues.
The Plight of the Guadalupe Bass
Every Day in May