(Unit 3-Topic 2) Hydro Power & Inter linking of Rivers

Indian Geography (Unit 3-Topic 2)

Hydro Power in India

Hydro-electric power is a renewable natural resource known for their almost nil GHG emission. The oldest Hydropower power plant in India is in Darjeeling District in West Bengal. Its installed capacity is 130KW and was commissioned in the year 1897.

India began with a humble 560 MW capacity in 1950-51. With over 41000 MW installed capacity and 15.2% share in total installed capacity, hydropower is second largest source of electricity generation after coal. However, in these years, the relative importance of Hydro power has come down mainly because the thermal power outperformed it.

Advantages of Hydro power

Hydropower is considered to be most economical source of power. Since no fuel is burnt to produce power, there is no problem of pollution. Oil, coal and natural gas resources which can be used for producing electricity are in short supply and have implications in terms of high costs and exert greater pressure on foreign exchange resources; Hydel power can easily replace them.

Is Hydropower completely clean?

Hydropower is not completely clean because the dams produce significant amount of CO2 and Methane, both GHGs. When a large dam is built, flora gets immerged in water and rots under anaerobic conditions producing methane. Thus, whatever negative impacts of Hydropower are there, they are mainly because of alternation of surroundings of the dams, natural habitats and wildlife.

The hydropower generation is highly capital-intensive mode of electricity generation but being renewable source of energy with no consumables involved; there is very little recurring cost and hence no high long term expenditure. It is cheaper as compared to electricity generated from coal and gas fired plants. It also reduces the financial losses due to frequency fluctuations and it is more reliable as it is inflation free due to not usage of fossil fuel.

Key problems in harnessing Hydro Power

India has one of the largest hydropower potential in the world but only one fifth of that potential has been harnessed so far. The key problems include high investment costs in building large dams, dependency on hydrology, problem of environment, loss or modification of the fish habitat and displacement of the local populations. These projects have long gestation period in comparison to thermal power projects.

Types of Hydro Power Projects in India

There are two types Hydro power projects in India viz. large and small. The small hydro projects has a capacity of less than 25 MW. The small hydro projects come under the Ministry of New and Renewable Energy. Ministry of Power is responsible for large hydro projects. The small hydro projects are further classified into Micro, Mini and small projects as follows:

World’s largest Hydro-electric power station

Three gorges project in China on Yang-Yang river is the largest power station in the world having installed capacity of around 18,200 MW.

Hydel Power+Thermal Power mix: Solution of Seasonal Load Curves

Seasonal load curves of India’s regional grids match with the pattern of hydro power generation. During summer/monsoon season when the generation at hydro power plants is high, the load factor of the system is high due to heavy agricultural load. During winter, the thermal stations operating at base load and hydro stations working as peak load stations will take care of weather beating loads. Thus the operational needs of hydro & thermal stations are complimentary and the balanced mix helps in optimal utilization of the capacity.

Problem of Sedimentation in Reservoirs

Sedimentation and silting in reservoirs leads to reduction in active storage capacity; makes flood management difficult and causes damaged to turbines due to abrasive action of silt. This is a major problem of the hydropower generation. The following are some approaches to tackle sedimentation problem of reservoir:-

• Catchment Area Treatment (CAT) for reduction of silt load includes forestations of the catchment area and constructions of check dams on the tributaries and upstream of the river.
• Effective desilting arrangements for prevention of silt.
• Silt resistant equipments of withstanding the silt.
• Effective operation of the reservoir to minimize silt deposition.

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Inter linking of Rivers

The idea behind ILR is to divert water from surplus rivers in the north and east, which face frequent flooding, to water scarce regions in the west and south, where droughts are a common occurrence.

History of the Proposals being made:

• The idea of interlinking of rivers in the Indian subcontinent is atleast 150 years old. During the British Raj in India, Sir Arthur Cotton, a British general and irrigation engineer, first suggested linking the Ganga and the Cauvery for navigational purposes. 
   
• Dr. K.L. Rao’s  Proposal (1972), which had  2640 km. long  Ganga - Cauvery link as its main component involved large scale pumping over a head of 550 m. The power requirement for lifting the water was huge, estimated to be 5000 to 7000 MW, for irrigating an additional area of 4 million hectares only. The scheme was also not having any flood control benefit.  Dr. Rao had estimated this proposal to cost about Rs. 12,500 crores, which at 2002 price level comes to about Rs. 1,50,000 crores.  The Central Water Commission, which examined the proposal, found it to be grossly under estimated and economically prohibitive.
   
• Capt. Dastur Proposal (1977) envisaged construction of two canals – the first 4200 km. Himalayan Canal at the foot of Himalayan slopes running from the Ravi in the West to the Brahmaputra and beyond in the east; and the second 9300 km Garland Canal covering the central and southern parts, with both the canals integrated with numerous lakes and interconnected with pipelines at two points, Delhi and Patna.  The cost estimated by Capt. Dastur was Rs. 24,095 crores.   The cost estimated by the experts in 1979 was about Rs. 12 million crores. The realistic cost at 2002 price level comes to about Rs. 70 million crores.
  

• The idea to link rivers got a shot in the arm with the establishment of the National Water Development Agency in 1982 by then prime minister Indira Gandhi. 
   
• The first National Democratic Alliance government (1999-2004) was keen to implement the interlinking of rivers (ILR) project, and the Supreme Court, following a public interest litigation, in 2003, asked for it to be implemented by 2016 
   
• I 2002, Supreme Court asking to expedite the project.

Component of National River Planning project:
It has two components:

a) Himalayan Component

b) Peninsular Component


Himalayan Component:

The Himalayan component envisages construction of storage reservoirs on the main Ganga and Brahmaputra Rivers and their principal tributaries in India and Nepal so as to conserve monsoon flows for irrigation and hydro-power generation, besides flood control.  Links will transfer surplus flows of the Kosi, Gandak and Ghagra to the west.  In addition, the Brahmaputra-Ganga Link will augment dry-weather flow of the Ganga.  Surplus flows that will become available on account of inter-linking of the Ganga and the Yamuna are proposed to be transferred to the drought prone areas of Haryana, Rajasthan and Gujarat.  With this proposal about 14 Mha-m of additional water would be available from these river systems for irrigating an estimated 22 M-ha in the Ganga-Brahmaputra basin apart from Haryana, Punjab, Rajasthan and Gujarat. It would also provide 1120 cumec to Calcutta Port and would provide navigation facility across the country. It will also provide flood moderation in the Ganga-Brahmaputra system. The Himalayan component will benefit not only India but also Nepal and Bangladesh. Fourteen links are proposed in the Himalayan component.

Proposed Fourteen Links in the Himalayan Component

1 KOSI-MECHI	2 KOSI-GHAGRA
3 Gandak-Ganga	4 Ghagra-Yamuna
5 Sarda-Yamuna	6 Yamuna-Rajasthan
7 Rajasthan-Sabarmati	8 Chunar-Sone Barrage
9 Sone Dam-South Tributaries of Ganga	10 Brahmaputra-Ganga (MSTG)
11 Brahmaputra-Ganga (JTF)(ALT)	12 Farakka-Sunderbans
13 Ganga-Damodar-Subernarekha	14 Subernarekha-Mahanadi

Peninsular Rivers Development Component
The main component of Peninsular Rivers Development is the “Southern Water Grid” which is envisaged to link Mahanadi, Godavari, Krishna, Pennar, and Cauvery rivers. The peninsular scheme was envisaged to provide additional irrigation benefits of over 13 million ha. The Peninsular component comprises the following four parts:

• Diversion of surplus flows of Mahanadi and Godavari to Krishna, Pennar, Cauvery and Vaigai.
   
• Diversion of west-flowing rivers of Kerala and Karnataka to the east.
   
• Inter-linking small rivers flowing along the west coast, north of Mumbai and south of Tapi.
   
• Inter-linking the southern tributaries of Yamuna.

The peninsular component of ILR has 13 major water storage/diversion structures situated in four basins. Three non-storage structures, viz., Dowlaiswaram barrage, Prakasam barrage, and Grand Anicut and storage node (Narayanpur) cater to only irrigation, while six storage nodes, viz., Inchampalli, Almatti, Nagarjunasagar, Pulichintala, Krishnarajasagar, and Mettur will serve both irrigation and power needs. One storage node, viz., Somasila is operated to meet domestic and irrigation needs and two storage nodes, viz., Polavaram and Srisailam are multi-purpose projects serving domestic, irrigation, and hydropower demands.

Proposed links in the Peninsular Component

1 MAHANADI(MANIBHADRA)-GODAVARI (D/S)	2 GODAVARI (INCHAMPALLI)-KRISHNA (NAGARJUNSAGAR)
3 Godavari (Inchampalli Low Dam)-Krishna (Nagarjunsagar Tail Pond)	4 Godavari (Polavaram)-Krishna (Vijaywada)
5 Krishna (Almatti) – Pennar	6 Krishna (Srisailam) – Pennar
7 Krishna (Nagarjunsagar) – Pennar (Somasila)	8 Pennar (Somasila)-Cauvery (Grand Anicut)
9 Cauvery (Kattalai) – Vaigai – Gundar	10 Ken-Betwa
11 Parbati-Kalisindh-Chambal	12 Par-Tapi-Narmada
13 Damanganga-Pinjal	14 Bedti-Varda
15 Netravati-Hemavati	16 Pamba-Achankovil-Vaippar

Water Availability and scarcity across the basin


Pros and Cons of the Project:

• It will lead to massive displacement of people 
   
• Since the Ganga basin’s topography is flat, building dams would not substantially add to river flows and these dams could threaten the forests of the Himalayas and impact the functioning of the monsoon system.
   
• The transfer of such enormous amounts of water will inundate forests and land for reservoirs, and the weight of billions of litres of water may even have seismic implications in the Himalayan region.
  

International Experience:

Source:economic times, the hindu