Interlinking of Rivers

Himalayan component

Posted by Susan Sharma on March 06, 2006

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  1. Brahmputra-Ganga
  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-Southern tributaries of Ganga
  10.  Brahmaputra-Ganga
  11.  Kosi-Mechi
  12.  Farakka-Sunderbans
  13.  Ganga-Damodar-Subernrekha
  14.  Subernrekha-Mahanadi

( Source-The Hindu)

Interlinking of Rivers

A new study says that river-linking will affect monsoons in the country

Posted by Susan Sharma on February 12, 2006

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This warning was issued in an article published in the January 10, 2006 issue of the journal, Current Science. The report, an outcome of a one-day meeting of scientists from a few premier research institutes of the country, suggests that the reduced runoff from some rivers targeted by interlinking — a sure consequence of the project — could adversely affect the amount, duration and spatial distribution of monsoon rainfall received by most regions in India.

Unlike other oceans, the Bay of Bengal maintains a low-salinity layer whose thickness varies between 10 and 20 metres during different periods of the year. This low-salinity region, spread over a third of the Bay of Bengal, owes itself to the runoff from some of the rivers targeted by the interlinking project, and plays a critical role in sustaining monsoon rainfall in major parts of the country. The region is a prime reason for India receiving nearly 4 per cent of the global precipitation, even though it occupies only 2.45 per cent of the earth’s terrestrial surface. India receives about 70 per cent of its annual precipitation from the summer monsoon.

Interlinking will upset this If the proposal takes effect, humongous amounts of water from the Ganga, Brahmaputra and Mahanadi river systems, that today flow into the Bay of Bengal, will be redirected to the water scarce regions in southern and western parts of the country. Scientists, however, feel that the government has ignored larger questions while pushing the project.

“The project should have been taken up only after carrying out a rigorous scientific study, employing proper modelling and simulation experiments,” says V Rajamani, professor of geology at the New Delhi-based Jawaharlal Nehru University one of the authors of the Current Science report. On Rajamani’s insistence, the Bangalore-based Indian Academy of Sciences organised the meet, which led to the Current Science article.

The participants included U C Mohanty of Indian Institute of Technology, Delhi, R Ramesh of Ahmedabad-based Physical Research Laboratory (PRL), Prasanna Kumar of National Institute of Oceanography, R K Kolli of Indian Institute of Tropical Meteorology, Pune, and G S Bhat and other scientists of the Indian Institute of Science Bangalore (IISC). Also present was another scientist from the iisc, P N Vinayachandran who, in 2002, had collaborated with two scientists of the National Institute of Oceanography in Journal of Geophysical Research article, which showed for the first time that freshwater inputs from river runoff are critical to the Bay of Bengal’s low-salinity layer.

The meeting deliberated upon the existing knowledge on the Bay of Bengal and its land-atmosphere linkages. The participants noted, “The estimated freshwater influxes into the Bay of Bengal from local precipitation and through river discharge are 4,700 and 3,000 billion cubic metre (bcm) per year respectively. The Bay loses only 3600 bcm per year. Thus, its annual freshwater input far exceeds the loss due to evaporation. This makes the Bay relatively less saline compared to other oceans.” Says Rajamani, this also helps the ocean maintain its low salinity area, and in turn influence the monsoon rainfall in most parts of the country. How? The density of seawater increases with salinity. The Bay of Bengal’s low-salinity zone is therefore a layer of less dense water that floats above denser waters below. Scientifically referred to as stratified layering, the phenomenon prevents mixing of surface water and the cooler waters below. Solar energy gets trapped in the top 10-20 metre-thick non-saline layer, keeping the sea surface temperature (sst) higher than other oceans. This is critical for rainfall.

According to meteorologists, low pressure formation that causes monsoon begins at 28° c but peaks at 29° C. But while other oceans, including the Arabian Sea, take almost a month to increase their sst by 1° c, the corresponding time required by the Bay of Bengal is just 4 to 5 days. Its warmer low-salinity zone enables the Bay of Bengal to effect this temperature change, faster. This is very significant, considering that even small changes in the sst influence rainfall. “This relation between the low-salinity layer in the Bay of Bengal and the monsoon rainfall was established scientifically during Bay of Bengal Monsoon Experiment in 1999,” says Vinayachandran.

More evidence Scientists also say that global circulation model studies have shown that its low-salinity zone also helps the Bay of Bengal retain freshwater from the river discharge closer to the coastal region during the monsoon period. And, then around the beginning October every year, when the monsoon withdraws, this water flows along the coast of India and around Sri Lanka into the southeastern Arabian Sea; here it plays a vital role in warming of the Arabian Sea during the pre-monsoon months. “This clearly shows that the effects of the rivers that originate in the Himalayas are not just local, but spread out over a large area on an annual scale,” the Current Science article observes.

Other impacts Says R Ramesh, a biological oceanographer with prl, the disappearance of the low-salinity region can lead to an increase in marine phytoplankton population. Currently this layer prevents vertical mixing of water between the rivers dense and rare zone, and this in turn inhibits supply of nutrients from below, restricting phytoplankton growth. The Bay of Bengal does have an abundance of phytoplankton, but the productivity of these creatures is only one-fourth of that found in the Arabian Sea. Increased phytoplankton population might lead to a growth in the Bay’s population. Scientists fear that this fecundity would work to the ocean’s detriment. Rains at bay The planktons will take away lots of oxygen from the Bay and will lead to the development of the oxygen minimum zone, just as in the Arabian Sea. Oxygen dependent bacteria would be replaced by nitorgen dependent ones, causing denitrification — the release of nitrogen oxide into the atmosphere. Nitrogen oxide is 20 times more potent greenhouse gas. Scientists have other worries. Says Rajamani, the country’s coastal ecology will be completely altered after the construction of more than 250 mega dams envisaged by the river linking project.

“In normal course, nature maintains equilibrium by constantly replenishing delta regions with sediments to offset those taken away by the sea or lost due to subduction. But the dams will reduce or even stop the supply of sediments from rivers and this in turn will accelerate sea erosion in the deltas,” he apprehends. The sea erosion triggered by dams was best documented by a team of researchers in the Andhra University, Visakhapatanam in a 2004 Current Science paper (See “Sea change”, Down To Earth, December 15, 2004). The scientists led by Kakani Nageswara Rao of the geo-engineering department of the university found the fertile delta region lost 18 sq km between 1976-2001 as a series of dams built on the river Godavari river and its tributaries blocked sediment flow.

Rajamani and other contributors to the Current Science article have called for more research to assess the impacts of river linking. The potential consequences of the project inferred in the report are based on existing knowledge on the Bay of Bengal. “There is a definite need to create more credible datasets on land, ocean and atmosphere so that simulation models can be prepared,” they argue. This will help establish the relation between the runoff input to the Bay of Bengal and the monsoons. more accurately. Significantly, currently no official data is available on how much water or at what rate water from these rivers will be diverted as part of the river linking project.

Interlinking of Rivers

Jawaharlal Nehru on large projects

Posted by Susan Sharma on January 25, 2006

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" The idea of doing big undertakings or doing big tasks for the sake of showing that we can do big things, is not a good outlook at all. For it is the small irrigation projects, the small industries and the small plants for electric power which will change the face of the country, far more than a dozen big projects in half a dozen places."

The then Prime minister drew his audience's attention to "the national upsets, upsets of the people moving out and their rehabilitation and many other things associated with a big project." These upheavels would be on a lesser scale in a smaller scheme, enabling the State to "get a good deal of what is called public co-peration".

-From a volume of Nehru's speeches on science and society, published 1988.

Interlinking of Rivers

Centre shelves Pamba-Vaippar river-linking project

Posted by Susan Sharma on January 07, 2006

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The Union Government has shelved the controversial project to link the Pamba and Achenkovil rivers of Kerala with Vaippar river in Tamil Nadu. The Kerala Legislative Assembly and the State Government have been appealing to the Union Government to give up the river linking project. The letter from the Union Government says: "It has taken note of the resolution of the Kerala Legislative Assembly and has decided not to treat the Pamba-Achenkovil-Vaippar Link as a priority link, for consensus-building purpose."

Interlinking of Rivers

Polavaram Project-Controversy

Posted by Susan Sharma on December 16, 2005

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The Orissa government has objected to the construction of the Polavaram project on the ground that the 150 ft high dam will submerge several villages and agricultural lands in that State and displace hundreds of tribal families and others. T

The Orissa Chief Minister has addressed letters to the A.P Chief Minister resenting the latter’s decision to go ahead with the execution of the project without consulting Orissa. The letter to the Central Water Commission expresses ire at the clearances given without referring them to his government.

It is understood that construction has started based on a 1980 interstate agreement signed by the three riparian states-Andhra Pradesh, Madhya Pradesh and Orissa. In the intervening 25 years the cost of rehabilitation and resettlement would have gone up considerably. A meeting between the two Chief Ministers is likely to settle the issue politically.

Interlinking of Rivers

Polavaram -linking Godavari and Krishna

Posted by Susan Sharma on December 12, 2005

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The report prepared by the NWDA(National Water Development Agency) on the 174km Polvarm link,  is available at the following link ( Please cut and paste in your browser)

http://nwda.gov.in/index3.asp?sublink2id=12

Chapter 14 of the report talks about the environmental and ecological impact of the project. The Polavaram reservoir submerges an area of 63,691 ha comprising of 60,063 ha in Andhra Pradesh, 2,398 ha in Chattisgarh and 1,230 ha in Orissa. Out of the total submergence area, the area under cultivation is about 30,650 ha and the forest area 3,705 ha. It is obvious that the project involves the displacement of a huge agricultural population most of them from Andhra.

To quote the report

"The main purpose of the Polavaram project is to provide water for irrigation to the ayacut upstream of the Godavari barrage, to supply drinking water to the Visakhapatnam steel plant and also to provide water to the chronic drought prone Cheepurupalle tract in which the manganese belt is situated ...........

"Submergence of forest area may have environmental and ecological impact: Proper Environmental Management Plan (EMP) will be evolved to reduce the impact on the environment due to the project. Also, to minimise the loss of forest additional afforestation programme will be taken up. Necessary provision has been made in the estimate for compensatory afforestation".

"The prospects of submergence leading to loss of homes and means of sustenance will have a traumatic effect on the affected population. The problems relating to resettlement and rehabilitation (R & R) are quite complex. It is essential that the contents of R & R package should be very attractive".

"A total of 16207 families are likely to be affected due to creation of Polavaram reservoir. These families would need to be resettled in different villages in the nearby areas. To avoid dispute and problems, the selection of suitable agricultural land in the command area and its division into required sizes and its distribution by draw of lot with the control of a High Level Committee comprising senior officers of concerned departments should be performed. In the case of Polavaram-Vijayawada link project, 30650 ha of culturable area is coming under the submergence of the proposed reservoir at Polavaram. Therefore, at least an equivalent area of land has to be acquired, suitably in the command area of the project for encouraging to carry out the normal agricultural activities by the affected families".

Interlinking of Rivers

Flow diversion of Ranganadi River, Arunachal Pradesh

Posted by Susan Sharma on November 25, 2005

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The Ranganadi Hydroelectric project (Phase I)was commissioned in 2001. This phase involved inter-basin transfer of water from the Ranganadi to the Dikrong using a flow diversion plan. Due to protests by affected local people, the diversion of water is being done at a low key and in a secretive manner and only partial generation of electricity is taking place.

A study by Aranyak, an NGO, with the assistance of BNHS revealed that

  • The flow diversion, even at the subdued level, caused shallow flooding to occur, converting cultivable land into marshland.
  • Shifting of the river has resulted in rendering bridges built on it redundant, calling for redesigning and reconstruction of the entire PWD road network on the two banks of the river.
  • A fast diminishing fish population and the disappearance of river dolphins point to the pollution and silting , a direct result of the construction activities.

It is understood that Ministries of Water Resources and Power and allied agencies mark all important documents on water resource projects as ‘classified’, denying public access to such documents. But interventions in the natural flow regime of rivers are extremely crucial and sensitive issues, having far reaching implications on the lives and livelihoods of people downstream. Implementing such plans without prior knowledge of stakeholders, concealing crucial information from people who are potential victims of such maneuverings is in utter disregard and denial of citizens’ basic human and environmental rights.

( Courtesy BNHS issue dated Ap-June 2005)

Interlinking of Rivers

M.S Swaminathan on river linking

Posted by Susan Sharma on October 31, 2005

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Well-known agricultural scientist and chairman, National Commission on Farmers, M. S. Swaminathan, has favoured construction of the Polavaram project and for that matter any big project, provided the environmental and social aspects are taken care of. Speaking to reporters after meeting the Chief Minister, Y. S. Rajasekhara Reddy, on Thursday, he said such big projects were the need of the hour in the light of the Bharat Nirman programme under which 1 crore hectares of additional ayacut would be brought under the plough. It was not the first time that big projects were taken up in the world, he said, citing the Aswan Dam in Egypt and the Three Gorges project in China. Dr. Swaminathan, however, wanted a realistic assessment of benefits and risks before embarking upon any big project. If a particular project displaced tribals and others and affected the environment, sufficient steps must be taken up. "It's a win-win situation for people and the environment. There is no free lunch." Asked to comment on Medha Patkar's strong opposition to Polavaram project, he said, "some people are ideologically opposed to big dams and prefer smaller ones." He said his policies "are going on right direction." During the meeting, Dr Swaminathan and the Chief Minister discussed the need for bridging the gaps between scientific knowledge and field-level needs.

Interlinking of Rivers

Medha Patekar on River linking

Posted by Susan Sharma on October 31, 2005

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A day after the State Government secured the much-awaited environmental clearance for the Polavaram (Indirasagar) project, noted environmental activist Medha Patkar and the tribals facing displacement strongly opposed the Government's moves to go ahead with the project. "What the project has secured from the Centre is only environmental clearance. But there is no forest clearance yet which is mandatory for any major dam," Ms. Medha Patkar said at an interface with the adivasis. Asserting that the project was part of efforts to boost industrialisation at the expense of agriculture and tribal areas, she volunteered to spearhead the agitations to be launched by tribals against giving clearances to Indirasagar project in violation of the people's right to life and the right to livelihood guaranteed by the Constitution.

Interlinking of Rivers

Green Clearance for Andhra Project

Posted by Susan Sharma on October 28, 2005

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One of India's first river-linking projects, Polavaram, received the Centre's environmental clearance on 26th October 2005. The Pollavaram project(AP), renamed Indirasagar, aims at taking 80 TMC of water from river Godavari, the country's second-largest river, to river Krishna. The multi-purpose project, when completed, will irrigate some three lakh hectares of farmland and generate 960 MW of power.

The revised project cost is Rs 13,000 crore, of which Rs 4,000 cr is to be used exclusively to address environmental issues, apart from relief and rehabilitation of 48,000 families across 288 habitations.

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