Model Question and Answers for APSC | Discuss advantages and disadvantages of Mega dam projects in Assam. (APSC 2011)
Ans : Advantages of Mega dam projects in Assam Dams are advantageous in different aspects. Dams ensure the benefits of improved health and life by supplying clean water, improved quality of sanitation, increased food (crop & fish) production, irrigation supply, protection of lives and goods from flood jeopardy, generation of electricity, tailings of mines and controlling the debris as well as the recreation and environmental benefits of the reservoirs.
Disadvantages of Mega dam projects in Assam
1. A large area gets submerged due to the rise in the water levels and turned into a reservoir.
2. Failure of Dams: Dams may sometimes fail due to excessive and unanticipated earthquakes particularly in the unstable Himalayan region of Assam.
3. Water wastage: Sometimes water used in excess of evapotranspiration requirements. This water appears in the system as surface or groundwater. But it degrades in quality, mainly due to fertilisers and pesticides, besides minerals drawn from soils. Such waste has to be minimised.
4. Life cycles of habitats living in the water (like fish) get affected due to the construction of dams.
5. Cycles and variation of flow downstream are established.
6. Standing water (reservoir) habitats replace flowing water habitats.
7. Nutrients are unable to proceed downstream.
8. Loss of riverine islands may be enhanced due to loss of debris transportation.
9. Productivity and species diversity of waterways are often reduced because of the reduction of fresh flow.