Retire Mechanical engineer. Student at California State university Channel Island studiyingAbout Me

April 29, 2017

River Dams

The study of the Snake River dams gives us a perfect example of how dam improvements can make a difference in the environment, as well as provide valuable knowledge that the rest of the world can apply to other dam projects.

It is interesting to note that civilizations have used dams as early as the Mesopotamian and Egyptian eras BCE. They used dams for flood control as well as to irrigate their crop fields.

According to Lt. Col. Vail, the study done by the U.S. Army Corps of Engineers on the four lower Snake River dams provides valuable data that is very important to take into consideration.

The major advantages of the dams include: the Snake River dams deliver clean renewable hydropower, they are an efficient marine transportation corridor, and they provide valuable recreational opportunities. They provide these benefits at a very reasonable cost while coexisting with fish and wildlife (Lt.Col. Tim Vail. U.S.Army Corps Engineers 2015).

In addition, the positive aspects of the dams are that they provide clean power compared to oil and coal operated power plants. This is important when considering the high greenhouse gas emissions emitted by coal and oil powered plants. The dams are also used to irrigate crops in areas that do not have access to water. Depending on where the dams are constructed, hydropower can provide highly-variable wind energy into the power grid (U.S.Army Corps of Engineers 2015).

According to Lt. Col. Vail, by having hydro-electric power, we are providing a side service and integrating with wind power. When the wind changes speed, hydropower can reduce or add power to wind generated power to keep the grid stable (Lt.Col. Vail 2015).

Also, Vail noted the availability of power is not interrupted and if the electricity is not needed the sluice gates are shut to save the water for irrigation purposes. Dams provide recreation to the public, which, in turn, brings funds. If the dams are built to allow fish to pass through that is an added advantage. In the case of the Snake River dams, they not only provide fish passage corridors, but also regulate the temperature of the river in dry seasons for the fish to survive (Lt.Col Vail 2015). 

 The disadvantages of the dams: the irregularity of water flow has the potential to dry up the river, which would kill the fish and reduce biodiversity, including birds and other mammals who reside alongside the river banks. If the dam is large, humans are displaced, and animals that depend on the flow to reproduce as part of their life cycle are put in danger. Migratory fish that mate in different locations on the rivers are unable to do so which results in declining fish populations.

The buildup of water behind the dam is also dangerous to plant life that grows on the natural shore lines of the river; as the water level rises the plants are submerged and die. It also stops the beneficial sediment that normally is washed down the river, which decreases the fertility of the soil downriver from the dam.

The destruction of failed dams occurred between 1889 and 1928 in US after knowledge was passed from Indians about the fisheries, destruction of salmon, sockeye and other fish population. For example, these dams prohibited salmon from swimming upriver to reach their destination to produce. This was the catalyst for public outcry and outrage, and the removal process started. It is not just the US that has problems, but the world at large has issues with dams. 

For example, in Southeastern Turkey a dam was proposed on the river Euphrates. When it was discovered that a very ancient city existed on the banks, a presidential decree was declared. The dam was built, but not allowed to fill with water until excavations were completed. Turkey also has continuous problems with the neighboring countries of Iraq and Syria over water issues. 

My personal view is that we need dams for the many benefits and reasons stated above. Dams can be beneficial to both humans, fish and other wildlife if properly constructed. But, there are major disadvantages as well. Dams are expensive to build and must operate for long periods of time to recover the construction costs. Flooding of a large areas of land means that the natural environment is destroyed. Therefore, dams should be built only in extreme circumstances and with consideration of not interfering with the natural flow of water.