DAM SAFETY

22nd July, 2021 Economy

Context:

PANIC gripped people in the Cauvery basin area after a small wall at Krishnaraja Sagar Dam collapsed

Dams are artificial barriers on rivers which store water and help in irrigation, power generation, flood moderation, and water supply.
In India, dams higher than 15 m or between 10 m and 15 m height that fulfil certain additional design conditions are called large dams.
As of June 2019, India has 5,745 large dams (includes dams under construction). Of these, 5,675 large dams are operated by states, 40 by central public sector undertakings, and five by private agencies.
Over 75% of these dams are more than 20 years old and about 220 dams are more than 100 years old.
Most of these large dams are in Maharashtra (2394), Madhya Pradesh (906), and Gujarat (632).
As a large amount of water may be stored in a dam’s reservoir, its failure can cause large scale damage to life and property.
Therefore, monitoring dam safety is essential.

The Central Dam Safety Organisation, under the Central Water Commission (CWC), provides technical assistance to dam owners, and maintains data on dams.
The National Committee on Dam Safety devices dam safety policies and regulations.
Currently, 18 states and four dam owning organisations have their own Dam Safety Organisations.
CWC provides that each dam owner should carry out pre and post monsoon inspections (covering site conditions, dam operations) every year.
However, as per a CAG report on flood forecasting, from 2008 to 2016, of the 17 states studied, only two had carried out such inspections.
A CWC Committee on Dam Safety (1986) had recommended unified safety procedures for all dams and suggested a legislative framework for dam safety.

In 2007, Andhra Pradesh and West Bengal passed resolutions requesting Parliament to make a law on dam safety.
Consequently, the Dam Safety Bill, 2010 was introduced in Lok Sabha under Article 252 (which allows Parliament to make laws on state subjects which will apply to those states that pass a resolution requiring such law).
The 2010 Bill lapsed with the dissolution of the 15th Lok Sabha.
The Dam Safety Bill, 2019 was introduced and passed by Lok Sabha in

The Bill provides for the surveillance, inspection, operation, and maintenance of all specified dams across the country.
These are dams with height more than 15 metres, or height between 10 metres to 15 metres with certain design and structural conditions.
It constitutes two national bodies: the National Committee on Dam Safety, whose functions include evolving policies and recommending regulations regarding dam safety standards; and the National Dam Safety Authority, whose functions include implementing policies of the National Committee, providing technical assistance to State Dam Safety Organisations (SDSOs), and resolving matters between SDSOs of states or between a SDSO and any dam owner in that state.
It also constitutes two state bodies: State Committee on Dam Safety, and State Dam Safety Organisation.
These bodies will be responsible for the surveillance, inspection, and monitoring the operation and maintenance of dams within their jurisdiction.
Functions of the national bodies and the State Committees on Dam Safety have been provided in Schedules to the Bill.
These Schedules can be amended by a government notification.
An o ence under the Bill can lead to imprisonment of up to two years, or a fine, or both.

Dam reservoirs cause water losses. This is believed as mainly a result of the considerable amount of evaporation losses from the huge sizes of surface areas of reservoirs.
Large dams are generally justified by regional and/or national macro-economic benefits while their physical impacts are locally concentrated, mostly affecting those within the confines of the river valley and along the river reaches.
The livelihoods of many millions of people also suffer because of the downstream effects of dams: the loss of fisheries, contaminated water, decreased amount of water, and a reduction in the fertility of farmlands and forests due to the loss of natural fertilizers and irrigation in seasonal floods. Dams also spread waterborne diseases such as malaria, leishmaniasis and schistosomiasis.
According to the study conducted dams can stop regular annual floods but often fail to hold back exceptionally large floods. Eg- Recent floods in kerala.
Because dams lead people to believe that floods are controlled, they lead to increased development of floodplains.
When a large flood does come, damages caused are often greater than they would have been without the dam.
Some scientists do not consider hydropower as clean power because of the destruction of river ecosystems and its many social impacts.
Internationally, private investors in power projects are largely avoiding large dams and prefer to invest in cheaper and less risky gas-fired power plants, solar and wind mills.