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Source: Indian Express


Prelims: Current events of national importance, Environmental pollution and degradation(Solar energy, hydropower, Joshimath, Teesta Low Dam, Paris Agreement etc

Mains GS Paper III: Conservation, environmental pollution and degradation,Solar energy and its use in different sectors particularly agriculture etc.


  • The crisis in Joshimath for over a month has led to conversations on the relevance of hydropower in the Himalayan region.
    • Glacier burst led to concerns over the Rishiganga hydroelectric project in Uttarakhand.





  • Hydroelectricity is a renewable energy source that uses the potential energy of the water stored in the dams, reservoirs, flowing rivers etc.
  • The falling or flowing water rotates the turbine which spins a generator and the mechanical energy of the generator is converted to electric energy and hence the electricity is generated from the water.
  • Hydroelectricity accounts for about 17% of the total electricity sources worldwide.
  • Hydropower is considered green energy because it generates electricity from the natural flow of water without releasing any emissions or pollutants.
  • It also does not rely on fossil fuels.


Environmental impact of hydropower

  • Large-scale hydroelectric dams impact local ecosystems and communities
  • They displace people and result in loss of habitat for fish and other wildlife.
  • The building and maintenance of large hydroelectric dams have a significant environmental impact.


Himalaya and hydropower:

  • They are a major water source for much of South Asia.
  • Most countries in the region, including India, China, Nepal, Bhutan, and Pakistan.
    • They have built or are planning to build hydropower projects in the Himalaya.
  • In India: the government has identified hydropower as a key renewable energy source.
  • Indian Himalaya:
    • Subansiri Lower Hydroelectric Project in Arunachal Pradesh
    • Teesta Low Dam Hydroelectric Project in Sikkim.



  • It has identified hydropower as a major source of energy.
  • It has many hydropower projects in the planning and development stages, including:
    • Arun III Hydroelectric Project
    • West Seti Hydroelectric Project.



  • Hydropower is the main source of revenue.
  • The government has set a target to export surplus electricity to India.
  • The country has built several hydropower projects:
    • Chukha Hydropower Project
    • Tala Hydropower Project.


Controversies about development of hydropower projects in the Himalayas:

  • Environmental impacts — in Joshimath and other parts of Uttarakhand.
  • Concerns about the potential conflicts over water resources in the region.
  • The Himalaya is a fragile ecosystem and home to a diverse range of flora and fauna.
  • It is threatened by deforestation, overgrazing, and construction activities that harm the environment and local communities that depend on it.


Negative Impact of dams:

  • The construction of dams can disrupt the flow of rivers, leading to changes in water temperature and chemistry.
  • It can cause erosion, landslides, and sedimentation which can have a negative impact on the local environment.
  • Dams disrupt the migration patterns of fish and other aquatic species and impact the local wildlife, particularly if the dam’s construction leads to habitat loss.
  • Large-scale hydroelectric dams displace local communities, affecting their livelihoods and cultural heritage and impacting the overall well-being of the local population.


Alternatives to hydropower:

Micro hydro:

  • It is a small-scale hydroelectric power generation system that typically generates up to 100 kilowatts (kW) of electricity.
  • These systems use the energy of falling water to turn a turbine, which, in turn, generates electricity.
  • They can be used for various applications, including:
    • powering homes
    • businesses
    • small communities.
  • Micro hydro systems are less expensive to build and maintain than large hydroelectric dams
  • They have a smaller environmental footprint.
  • They can be located even in inaccessible areas where it is difficult to transmit electricity from larger power stations
  • They can provide a reliable source of energy to communities that are not connected to the grid.


Micro hydro systems can be classified into two main types:

  • Run-of-river systems use the natural flow of water in a stream or river to generate electricity.
  • Storage systems use a reservoir to store water and release it as needed to generate electricity.


Way Forward

  • Micro hydro systems can be tailored to minimize the ecosystem’s negative impact and provide sustainable energy solutions.
  • Even micro-hydropower projects can have some impact on the environment and local communities.
    • A detailed assessment should be carried out to evaluate the potential impact before proceeding with the project



Q. Describe the various causes and the effects of landslides. Mention the important components of the National landslide Risk Management Strategy.(UPSC 2021) (200 WORDS, 10 MARKS)