From UPSC perspective, the following things are important :
Prelims level : How dams exacerbate disasters
Mains level : Paper 3- Role of dams in exacerbating disasters
The article explains the link between the disasters in the Uttarakhand and the construction of dams.
How dams exacerbate disasters
- The use of explosives has repeatedly been questioned for dam construction, and the construction of other infrastructure projects, such as roads, in the fragile Himalayan State.
- Other than this, deforestation takes place when dams are constructed.
- The construction material that is supposed to be dumped on separate land is often dumped into the rivers.
The Chopra Committee report after Kedarnath flood
- The Chopra Committee report of 2014 brings more clarity on how dams exacerbate a disaster such as floods.
- Its report mentions how dams exacerbated the 2013 deluge, mainly as riverbeds were already raised from the disposed muck at the dam construction sites.
- The report presents evidence to prove that dams are not only damaged in floods, they also cause immense damage in downstream areas.
- This is because as floodwaters damage a barrage, they increase the destructive capacity of the water that flows downstream of the barrage.
- In an affidavit submitted on December 5, 2014 in the Supreme Court, the Union Ministry of Environment, Forest and Climate Change acknowledged the adverse impact of dams in the 2013 floods.
Impact of climate change and threat of earthquakes
- Himalayan glaciers are receding and disintegrating as a result of climate change, and the snow cover in the Himalayas is also thinning.
- Research shows an increase in number and volume of glacial lakes as a result of of increased temperatures.
- For dams, this means rapid increase or decrease in the reservoir water level.
- It also means that the projections on the life of a dam reservoir may not stand due to erratic events, such as floods, that could rapidly fill a reservoir with muck and boulders brought along with the floods.
- In terms of earthquake risk, Uttarakhand lies in Seismic Zone-IV (severe intensity) and Seismic Zone-V (very severe intensity).
- Ignoring this, many dams have been constructed in zones that are under high risk of witnessing severe earthquakes.
Consider the question “Examine the role played by the dams in exacerbating the disasters in the Himalayan states”
It is clear that dams worsen disasters, and for this to be ignored by the State authorities is unfortunate.