Assume that the electricity generation capacity is only 50% of the designed capacity in one big hydro-power plant. Its design is the conventional dam type and not pumped storage type plant. However, the massive storage of water is in that hydropower plant for the whole year due to the reasons of the flood controls and the reserve capacity.
Then, what adverse impacts can be caused? How can mitigate?
-Shut down of hydro turbines and generators for long time
-Improper environmental flows
-Low velocity at the downstream side of the power plant
-Sedimentation
-Negative ecological impacts
-Undesirable social impacts
All the negative impacts you listed are valid, I want to add some more. In Hungary, we have flood control and dams in the last 120 years. They caused natural disasters and provided benefits as well. Usually, these types of hydro power plants have a disastrous impact on the ecosystem up to the dam in the zone where the water speed decreased.
The avoided floods below the dam also cause problems. They have an important role in fertilizing the soil and lower the sodium content. Especially, if improper irrigation applied to improve the crops yield, you would experience declining soil fertility and salinization (Hortobagy in Hungary).
Fish species affected since they spawn during the flood periods. The diversity and the number of fish will drop below the dam. Those species run up for spawning can be devastated without established fish paths (sturgeon was extinct in Danube river).
While the groundwater level will be higher above the dam, below the dam, it will be lower, since the bottom of the riverbed will sink. You can add more cross-dams to eliminate this effect, but all the other adverse effects listed above will occur on a longer part of the river.
You need to mitigate these problems, but there are clear tradeoffs, some unavoidable damages for the benefits of the dam.
Hello Dr.Robert Istvan Radics,
It's very great pleasure for your very specific and valuable answers by referencing the Hydropower scenarios in Hungary.
Big Congratulations!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Have a Very Nice Day!
It is argued that no interference should be caused to the river system, as rivers are meant for flowing. However as human beings we always consider only our needs. In the event of draught or flood, having a dam to control and conserve water will be a great idea. But this will definitely have its own advantage and disadvantages. One good thing in hydro electric projects is that, the dams are mostly for diversion purpose than pooling/conserving, and secondly once the water is out from the turbines they will be allowed to flow through the lower reaches of the same stream course, as the hydro-electric schemes are not consumptive type like irrigation.
As already listed above, the environmental problems are:
1. Reduction in the summer flows, causing lower environmental flows and salinity ingression.
2. Reduction in sediment load, which is important for ecological and hydrological demands.
3. Enhance of pollution in the lower reaches, due to absence of flushing effect.
4. Reduction in groundwater recharge due to absence of lean flow, especially in summer period.
The important factor here is to have a detailed environmental impact study before taking up large developmental work.
Hello Dr. Prasad,
I'm very delighted for your excellent answers.
Yes, the human activities cause the negative impacts to the ecosystems.
So, we do perform the EIA, SIA, ESIA before the implementation of the big hydropower projects.
Thank you so much.
Have a Very Good Day!
https://www.researchgate.net/publication/317379283_Nile_River%27s_Basin_Dispute_Perspectives_of_the_Grand_Ethiopian_Renaissance_Dam_GERD
Article Nile River's Basin Dispute: Perspectives of the Grand Ethiop...
Hello Prof. Dr. Hilmi S. Salem,
Big Thanks for your kind share!!!
Have a Great Day!
Dam construction do cause the ecological changes in both up and down streams catchments. The submergence of upstream periodically change flora and fauna and other activities in the area similarly in down stream the flow of ecological process like migration continuity of organism flow is checked and same can not be down stream until it has been reestablished. so the more loss for downstream in terms of biodiversity.
Hello Dobriyal,
Yes, of course, I agree that the downstream side is much impacted by Dam construction.
My discussion is regarding the improper storage of water in the Dam.
Thanks a lot.
Have a Nice Day!
https://www.researchgate.net/publication/320033244_Sustainability_in_Hydropower_and_Safe_Fish_Passage
Technical Report Sustainability in Hydropower and Safe Fish Passage
Hello Dr Golam Kibria,
Thank you so much for your kind share.
Have a Great Day!
Hello Dr Golam Kibria ,
Your research contribution is really great. Thank you so much. Congratulations!
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