Article Title: Down Go the Dams
Keypoints:
- Start of 20th century: Fossil Creek= spring-fed waterway sustaining an oasis in middle of AZ desert; it was very diverse
- Fossil Creek drained by 1916; re=located into 2 hydroelectric plants
- By 2010, the Fossil Creek generating stations were providing less than 0.1 percent of Arizona's power supply
- Summer 2005: utility workers retired the dams and the flow of Fossil Creek returned to normal.
- There are 800k operational dams worldwide today (45k of them over 15 meter tall)
- Dams control flooding and provide water for a number of different uses
- In U.S., the rate of dam removal has exceeded the rate of construction
- 70 dams have fallen in the last 2 years
- Other countries such as France, Australia, China, Japan, and Canada are also working towards removing dams
- When the dams are removed, there is a great increase water clarity and oxygen levels, also in biodiversity
- The release of sediments trapped behind a dam's walls can choke waterways, muddying the environment and wiping out insects and algae, which are important food for fish.
- Sediments that are not washed downstream can become problematic as well; as they dry out, they may provide fertile ground for potentially noxious exotic plants whose seeds they harbored.
- Often a big issue facing managers is what to do with accumulations of dirt and debris.
- In the case of Fossil Creek, engineers decided to reroute water around the dam, keeping it as a barrier to exotics and permitting frogs to survive in the backwater.
- To return the native fish back to their natural habitats, scientists caught as many fish as they could and put them in a giant tank, adding poison to kill any exotics. The ones who survived were then returned to the wild
- There is so much sediment in the Matilija Dam that it is unusable for drinking
- Many engineers who were once dedicated to building the dams now find themselves taking them down
Summary:
In the world, about eighty-thousand dams are present. Due to many of them becoming old and
rusty, people are starting to tear them down resulting in a pros side and cons side. One pro is the biodiversity
of the ecosystems. The ecosystems that used to be in the dams were being disrupted from the dams. Because
of the tearing of the dams, the biodiversity is able to flourish again. The con of tearing them down is that it
releases many toxic chemicals and heavy metals present in the old solids that made up the dam. These
substances can heighten the concentration of toxins in the water messing up the ecosystems all over again.
Thoughts:
When reading this article, I was actually surprised. When thinking of dams, I think of something
massive such as the hoover dam. Knowing that there are eighty-thousand dams makes it really surprising for
me. If dams as big as the hoover are being taken down, many toxic chemicals have got to be released into the
water.
In the world, about eighty-thousand dams are present. Due to many of them becoming old and
rusty, people are starting to tear them down resulting in a pros side and cons side. One pro is the biodiversity
of the ecosystems. The ecosystems that used to be in the dams were being disrupted from the dams. Because
of the tearing of the dams, the biodiversity is able to flourish again. The con of tearing them down is that it
releases many toxic chemicals and heavy metals present in the old solids that made up the dam. These
substances can heighten the concentration of toxins in the water messing up the ecosystems all over again.
Thoughts:
When reading this article, I was actually surprised. When thinking of dams, I think of something
massive such as the hoover dam. Knowing that there are eighty-thousand dams makes it really surprising for
me. If dams as big as the hoover are being taken down, many toxic chemicals have got to be released into the
water.
So what?Toxicity of the water could be affected when the dams are taken down
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Says who?Jane C. Marks
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What if?What if dams never eroded?
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The reminds me of...The Great Wall of Chine because dams are like walls.
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