Question

what are it's disadvantages of hydroelectric plants​

Answer 1

Answer:

disadvantages of hydroelectric plants

Fish populations can be impacted if fish cannot migrate upstream past impoundment 

dams to spawning grounds or if they cannot migrate downstream to the ocean. Upstream fish passage can be aided using fish ladders or elevators, or by trapping 

and hauling the fish upstream by truck. Downstream fish passage is aided by

diverting fish from turbine intakes using screens or racks or even underwater lights

and sounds, and by maintaining a minimum spill flow past the turbine.

Hydropower can impact water quality and flow. Hydropower plants can cause low 

dissolved oxygen levels in the water, a problem that is harmful to riparian

(riverbank) habitats and is addressed using various aeration techniques, which 

oxygenate the water. Maintaining minimum flows of water downstream of a 

hydropower installation is also critical for the survival of riparian habitats.

Hydropower plants can be impacted by drought. When water is not available, the 

hydropower plants can't produce electricity.

New hydropower facilities impact the local environment and may compete with other 

uses for the land. Those alternative uses may be more highly valued than electricity

generation. Humans, flora, and fauna may lose their natural habitat. Local cultures

Answer 2

Disadvantages of Hydroelectric plants :

• Construction of dams may lead to ecological damage.

• A large variety of plants, animals and their habitats get submerged in water.

• It decreases the fertility of the soil in the downstream area and affects crops.

• Dams can be constructed only at Limited number of places preferably in hilly terrains.

• The vegetation that gets submerged under water at the dam side decompose under anaerobic conditions and gives rise to methane which is a greenhouse gas .

• It creates the problem of satisfactory rehabilitation of displaced people.

• The blocking or changing the course of a river affects the fish and other organisms of the river.

Due to such disadvantages, construction of dams are opposed.

Example - Tehri dam project on river Ganga and Sardar Sarovar Dam on river Narmada.