[https://youtu.be/zcUrUE6-ZCw](https://youtu.be/zcUrUE6-ZCw)
I just watched The B1M’s video on removing four dams in the northwest, and they said that the sediment buildup behind a dam is bad for the environment but didn’t say why. What’s wrong with it?
In: 1
If you just let these sediments wash down river they are going to settle other places. This may alter the course of the river causing some areas to flood and others to dry up. But it will also be a big issue for the animals and plants living in the river. For animals they depend on the oxygen in the water but when you get too much sediments these will suffocate as the gills gets clogged with sediments. Just like how humans can suffocate if there is too much dust in the air. Plants as well do not like to be covered in sediments and will die from this. Even things like seeds and eggs that get buried too far down on the riverbed will not make it.
In addition to this a lot of dams are built near industries like factories, refineries, smelters and mines. These used to release toxic chemicals and heavy metals into the rivers. And these often get captured by the sediments and are just waiting there to be released.
[deleted]
Sediment is the material that rivers carry and deposit along their course.
However, when a dam is built, it blocks the natural flow of sediment downstream.
This causes several problems for the environment, such as:
* **Loss of reservoir storage**. The sediment accumulates behind the dam and reduces the water storage capacity and the life span of the reservoir.
* **Deprivation of downstream sediments**. The sediment that is trapped behind the dam is no longer available for the downstream river channel and floodplain. This affects the shape and stability of the riverbed, and the diversity and productivity of the aquatic habitats.
* **Increased erosion**. The water that is released from the dam is clear and sediment-free. This means that it has more power to erode the riverbed and banks downstream, causing erosion and degradation of the channel.
* **Changes in water quality**. The sediment behind the dam can affect the water quality in the reservoir and downstream. For example, it can release nutrients that cause algal blooms, or pollutants that contaminate the water.
Latest Answers