Critical analysis

A dam is a structure that is built on rivers, streams, or estuaries for conserving water. It directly helps to supply people with adequate water for consumption, industrial and irrigation purposes.

The dams and reservoirs world over have been playing dual role of harnessing the river waters for accelerating socio-economic growth and mitigating the miseries of a large population of the world suffering from the vagaries of floods and droughts. Dams and reservoirs contribute significantly in fulfilling the following basic human needs:

• Dams and reservoirs are constructed to store surplus waters during wet periods, which can be used for irrigation, industrial purposes as well as drinking. One of the major benefits of dams and reservoirs is that water flows can be regulated as per requirements of the various regions over the year.
• Floods in the rivers have been many a time playing havoc with the life and property of the people. Dams and reservoirs can be effectively used to control floods by regulating river water flows downstream the dam.
• Energy plays a key role for socio-economic development of a country. Hydro Power provides a cheap, clean and renewable source of energy.
• Enhanced inland navigation is a result of comprehensive basin planning and development, utilizing dams, locks and reservoirs that are regulated to play a vital role in realizing large economic benefits of national importance.

While dams provide service to the mankind, but it raises socio-economic and environmental issues.

• As a result of dam construction and holding of sediments in reservoirs, sediment feeding of downstream channel or shore beaches is prevented. Corrosions may occur. As the transfer of sediments is avoided by this way, the egg lying zone of the fishes living in the stream ecosystem is restricted, too.
• Reproduction of migrating fishes is hindered by the floods that harm the egg beds. Or the egg gravel beds can be destructed while the excavation and coating works in the stream beds.
• Temperature of water, salt and oxygen distribution may change vertically as a consequence of reservoir formation. This may cause the generation of new living species.
• Normal passing ways of territorial animals are hindered since the dam works as a barrier. Meantime the upstream fish movement aiming ovulation and feeding is prevented and thus fish population decreases significantly
• There will be serious changes in the water quality as a result of drainage water returning from irrigation that was done based on the irrigation projects. In other words, over transfer of food and the increase in salt density can raise water lichens and may change water living species.
• Discharge of toxic matters (pesticides, toxic metals etc.) and their condensation in food chain may affect sensitive animals immediately; all living organisms may expire when the stream becomes unable to recover itself.
• The water regime may change as a result of destruction of nature, unexpected floods may occur and consequently vegetation and natural structures in the riverbanks can be damaged.
• Some increase in earthquakes may occur because of filling of big dam reservoirs.
• Rise in evaporation loses may be expected as a result of the increase in the water surface area.
• Microclimatic and even some regional climate changes may be observed related to the changes in air moisture percentage, air temperature, air movements in big scale and the changes in the region topography caused by the stagnant, big scaled mass of water.
• Water-soil-nutrient relations, which come into existence downstream related to the floods occurring from time to time in a long period of time, change. Depending on this fact, compulsory changes come into existence in the agricultural habits of the people living in this region and also in the flora and fauna.
• Dams may cause increases in water sourced illnesses like typhus, typhoid fever, malaria and cholera.
• Dams affect the social, cultural and economic structure of the region considerably. Especially forcing people, whose settlement areas and lands remain under water to migrate, affect their psychology negatively.

Dams usually play a role in mitigating the impacts of regular floods. At the same time they introduce a catastrophic hazard of even greater flooding in the event of dam failure.

Dam failure has multiple instigating factors, both man-made (bad design, ineffective monitoring, bad operations & maintenance (O&M) etc.) and natural (heavy rains, landslides etc.). Therefore, knowing how existing and proposed dams can fail, and the consequences of their failure is crucial for mitigating disaster risk created by their construction. Most recently heavy floods reportedly damaged the barrages of the Rishiganga hydropower dam, which exacerbated the flood and led to significant human casualties and property damage.

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. Hence government has enacted Dam Safety Act.

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 devises dam safety policies and regulations. Earlier, 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 but lapsed with the dissolution of the 15^th Lok Sabha.  The Dam Safety Bill, 2019 was introduced in Lok Sabha on July 29, 2019, and passed by Lok Sabha on August 2, 2019. Rajya Sabha has passed it in 2021.

The Dam Safety Bill provides for adequate surveillance, inspection, operation, and maintenance of all the large dams in the country so as to prevent dam failure related disasters. The Bill provides for an institutional mechanism at both Central and State levels to address structural and non-structural measures required for ensuring the safe functioning of dams.

The Dam Safety Bill provides for adequate surveillance, inspection, operation, and maintenance of all the large dams in the country so as to prevent dam failure related disasters. The Bill provides for an institutional mechanism at both Central and State levels to address structural and non-structural measures required for ensuring the safe functioning of dams.

The provisions are:

• The Bill applies to all specified dams in the country. These are dams with: (i) height more than 15 metres, or (ii) height between 10 metres to 15 metres and satisfying certain additional design conditions such as, reservoir capacity of at least one million cubic meter, and length of top of the dam at least 500 metres.

Obligation of dam owners

• Dam owners will be responsible for the safe construction, operation, maintenance and supervision of a dam. They must provide a dam safety unit in each dam.  This unit will inspect the dams: (i) before and after monsoon season, and (ii) during and after every earthquake, flood, calamity, or any sign of distress.  Functions of dam owners include: (i) preparing an emergency action plan, (ii) carrying out risk assessment studies at specified regular intervals, and (iii) preparing a comprehensive dam safety evaluation through a panel of experts. 

Dam safety authorities and delegated legislation

• The Bill provides for dam safety regulatory and monitoring authorities at the national and state level. The functions of the national bodies and the State Committees on Dam Safety have been provided in Schedules to the Bill.  The central government can amend these Schedules through a notification.
• At the national level, it constitutes (i) the National Committee on Dam Safety, whose functions include evolving policies and recommending regulations regarding dam safety, and (ii) the National Dam Safety Authority, whose functions include implementing policies of the National Committee, and resolving matters between State Dam Safety Organisations (SDSOs), or between a SDSO and any dam owner in that state. The central government may notify the qualifications, and functions of the officers of the National Dam Safety Authority.  
• At the state level, it constitutes the (i) State Dam Safety Organisations (SDSOs), whose functions include keeping perpetual surveillance, inspecting, and monitoring dams, and (ii) State Committee on Dam Safety which will supervise state dam rehabilitation programs, review the work of the SDSO, and review the progress on measures recommended in relation to dam safety, among others. State governments may notify the qualifications, and functions of officers of the State Dam Safety Organisations.  They may also notify dam safety measures to be undertaken by owners of non-specified dams. 

Offences and penalties

• Anyone obstructing a person in the discharge of his functions under the Bill or refusing to comply with directions may be imprisoned for a year. In case of loss of life, the person may be imprisoned for two years.