A river is a natural resource, river have been used a source of water for obtaining food for transport, irrigation and as a determine measure as a source of hydro power. There are an integral relations between the river and the human civilization, river has been used for navigation for thousand years, the earliest evidence of navigation is found in the Indus valley civilization which existed in north eastern India around 3300 B.C.
The electricity is a very necessary part of our daily life; the electricity is the result of river water by using scientific manner the river dam or hydro power project provide the electricity for using river water in a scientific manner, a dam is a barrier that stop or restrict the flow of the water or underground streams for activities such as irrigation, human consumption industrial use, navigability, hydro power etc.
A river dam or hydro power project is a development process of government, it provide the electricity and some other facilities of us. Electricity is the key forces of various development plans and programs which are taken by the government. But some section of society opines that, “a dam may be not develop oriented if it effect the human life, or socio economic condition and environment.
But governments try to make or built dam to reduce the problem lake of electricity. Therefore occurred the anti dam movement.
A) What is dam or big dam? A dam is an artificial thing it’s made by using natural water resource, for generates electricity and some other purpose such as irrigation, navigation etc. A dam is a barrier that stop or restricts the flow of water or underground streams.
International commission of large dams (ICOLD) define large dams as higher than 15(49ft) and major dams as over 150m (490ft) in height.
‘ICOLD’ define some feathers of large dam those are:
i. A large dam is classified as one with a maximum height of more than15 meters from its deepest foundation to the crest.
ii. A dam between 10 and 15 meters in height from its deepest foundation is also included in the classification of a large dam provided it complies with one of the following conditions.
iii. Length of crest of the dam is not less than 500 meters or
iv. Capacity of the reservoir formed by the dam is not less than one million cubic meters or
v. The maximum flood discharge dealt with by the dam is not less than 2000 cubic meters per second.
B) Lower Subansiri Hydro Electric Project
The lower Subansiri Hydro Electric Project, official name Subansiri Hydro Electric Power Project (LSHEP) is a mega dam project and Brahmaputra Board handed over the project to NHPC In May, 2000 and its construction began on December, 2000. ‘LSHEP’ is a concrete gravity dam which is located in the Lower Subansiri district of Arunachal Pradesh. The height of LSHEP is 116m (381ft) and length is 284m (284ft) it is located 2.3km upstream of Gerukamukh village in Dhemaji district and Lower Subansiri district on the border of Assam and Arunachal Pradesh states. The project is expected to supply 2000MW of power when completed.
The Lower Subansiri hydro electric project and its impact:
Impact on Livelihood:
The Lower Subansiri Hydro Electric Project is a mega dam project of India. The expert committees and another some organization opine that is this dam will be complete than it will be very danger for the Assam and basically Dhemaji and Lakhimpur district of Assam. The Lower Subansiri river valley within Assam is inhabited by agriculture based rural communities with considerable density (256 persons per sq.km. as per 2001 census report) downstream people of the river is basically cultivators, fishers, agriculture based economy is their back bone. When the dam will completed defiantly the flow of water level will be reducing rapidly and harm the fishers and cultivator classes because that water level is not adequate to survive their livelihood.
And other hand Subansiri river are used as transportation and communication routes and some people also concern with the boat, or machine boat services it is their occupation, but when dam will be completed this occupation may be destroy due to lack of flow of water into downstream.
Impact on Environment or Biodiversity:
Study showed that the downstream of the river harbors a rich fish diversity (138 species) with other aquatic animals.
The Subansiri river is an important habitat for the most endangered freshwater dolphin the existence and maintenance of their population largely depend on the river as their preferred sustainable breeding ground their interconnected wetlands of the river also have many fish species included few rare and endangered one these needs to be protect in the event of the coming dam project which will destroy the quality of their habitats. The riparian eco-system being maintained along the river which harbors 230 species of plants, 308 birds, 19 mammals and other animals will be seriously affected due to artificial regulation of the river water.
Some expert committee and some observer showed that, if the dam will be broken than, its flood destroy the Lakhimpur and Dhemaji as well as Assam in few minutes.
Impact on Assam and Anti dam movement in Assam:
Assam is a riverine state of India, and India government already proposed many dam construction in Assam, Assam have been fighting for several years against a proposed gargantuan network of dams across the upper reaches of its rivers in Arunachal Pradesh, the long enduring anti dam movement in mainly geared against the state government and National hydro power corporation (NHPC).
The people of Assam now fighting together against a proposed network of 168 mega dams across Arunachal Pradesh one of the world’s most seismically region.
The anti dam movement in north eastern of Assam especially the one against the Lower Subansiri Hydro Electric Project. The project itself was proposed by the Brahmaputra flood control commission in 1955, with a view to flood moderation and irrigation, finely Brahmaputra Board transferred the project to ’NHPC’ in 2000 without any decision regarding the scientific investigation after which a scientific expert committee was set up to investigate the 2000 megawatt project NHPC had began the work without warring out a downstream study. So when the final recommendation of expert committee came out on June, 2010 the public mood grew against the dam rapidly.
After public hearing in the state capital of Guwahati in September, 2010 former environment minister Jairam Ramesh wrote a letter to Prime Minister of India regarding Lower Subansiri Dam.
All Assam Student Union (AASU) and allied with 26 ethnic organization in 2010 kick off a fully fledged agitation. Akhil Gogoi General Secretary of Kishak Mukti Sangram Samiti (KMSS) also appeared as a powerful player in the anti dam disquiet. Gogoi an activist and peasent leader he has been able to successfully mobilize popular sentiments against the dam.
Recommendation on Lower Subansiri Hydro Electric Project by expert committees:
• The Lower Subansiri Hydro Power Project has bee.n starting since 2000, but earlier investigation was not sufficient and later several investigator, was observer and expert committee give their suggestion and recommendation regarding this dam.
Recommendation on the Feasibility and the Safety of the dam :
• The present investigations carried out to examine the downstream impact of the lower Subansiri hydro electric dam project reveal gross inadequacy in the relevant facts relating to the construction of the construction of the dam at the present site for the mega dam of present dimension was not appropriate in such a geologically and seismologicaly sensitive location. The seismic design parameter is not properly chosen for the project.
• Future the geological, tectonic and seismological point of view the expert group suggest not consider the Himalayan foothills, for mega hydropower project.
• It is recommended to redesign the project by sufficiently reducing the dam height and production capacity.
Recommendation on Downstream Impact of the Redesigned dam :
• The inevitable siltation problem and its
management are not properly addressed by NHPC to regulate the resulting siltation problem, frequent flushing of the of the sediment to the downstream and dredging of river bed to maintain the original bad level is to be carried out throughout the river course, upstream catchment treatment with maintenance of slope and plantation needs to be carried out by identifying the erosion prone areas to minimize soil erosion.
• As Assam witnesses flood waves during the month from May to September, flood cushioning provision should sufficiently be kept for the period to minimize the dam-induced flash flood be kept in the reservoir.
• The spill way design is based on the recorded maximum discharge of 12024 cumec, where as the maximum discharge recorded was more than 21230 cumec on 11 July, 1971. So the expert group recommends reexamination and redesigning of spillway as per the recorded discharge data given above.
• It is doubted that the project will have negative impact on the easy availability of locally very important river supported by providing some better and acceptable alternative means for survival.
• Creation of irrigation potential in all the three ‘Zones’ by suitably through cannels from near the outflow of the turbine will improve the present pattern of yield and output of crops in the area this will also restore the groundwater condition and surface water availability in the wetlands of the downstream catchment of the Subansiri.
Investigations and Clearances:
Subansiri lower hydro electrical project has been designed and being constructed after getting investigated and cleared from various Government agencies namely:
• Geological survey of India.
• Central water commission, New Delhi.
• Central and Power Research Station.
• Department of Earthquake Engineering.
• IIT Guwahati.
• Botanical Survey of India.
• Zoological Survey of india.
• State Forest Research Institution, Itanagar.
Safety and Stability of Dam:
• Dam of Subansiri Lower Hydro Electric Project (2000mw) is a concrete gravity dam.
• There is no case in history of failure of a concrete gravity dam
• Although capacity of Subansiri Lower Project is 2000mw, its dam is not a major dam as the height of the dam is 116 meter. Only earlier Brahmaputra Board had proposed a 257 meter high rock hill dam at same site.
• 50 meter deep concrete cut off wall, which is a special and unique feature of this dam, will be provided for dam foundation to make it seepage proof and provide extra safety to dam body.
Earthquake Resistant Structure:
• A detailed study on the site specific seismic design parameters has been done by department of earthquake engineering IIT, Roorkee and approved by National Committee on seismic design parameters, government of India.
• On 26th December 2004, Andaman and Nicobar Island experienced the most devastating Tsunami in recorded history and Uri dam in constructed by NHPC when occurred 7.6 magnitude earthquakes 8th October 2005.
Flood Protection:
• Subansiri lower dam will have 9 spill ways to pass the probable maximum flood.
• The project would help in flood control by regulated discharge of water in river. During flood period the reservoir will be operated 15m below the FRL having flood cushion 442 m.cum.
Mitigation measures:
Lower Subansiri Hydro Power Project is a big dam project of Indian Government, regarding this dam the anti dam movement has been occurring since the year of 2000 for the fear of bad affection in Assam. The expert committee and some other study group already observe about the dam.
Some mitigation measures regarding this dam as mentioned under:
• There should be reduce the height of the dam.
• Positive attitude should be adopted by the government, non-governmental organization and other political or non-political organization.
• Recognition and respect should be given to the recommendations of expert committee.
• The government should initiate awareness programs.
• The central government as well as the state government should provide special employment opportunities to the downstream people who will go to lost their occupation for the dam.
• NHPC should be implementing the redesigned dam structure which is provided by several expert committees.
The electricity is important for us the production of electricity is one of important things to the fulfillment of the people’s demand regarding the lack of electricity government proposed the mega dam project, but study and observation group showed that the mega or big dam project may be destroy the human life environment or bio-diversity.
We support development but we does not advocate that development who will later harm or destroy our life or security. We are not against the development. But if development comes at the cost of the life, security and civilization of the people that development cannot be regard as a development.
The study has identified that, 968 revenue villages of Lakhimpue and Dhemaji district falling under the different impact zones. So that Lower Subansiri Dam Project directly harms the peoples of Lakhimpur and Dhemaji as well as Assam.
For the secure of the interest of the government. Government should not be adopted that policy which harm the life, property and security of the people.
A tripartite conference among government, NHPC and various organization of Assam and the public opinion for the construction of dam is very necessary for solving and mitigation of this problem.
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