WHY MODIFY SARDAR SAROVAR PROJECT
Director, Centre for Environmental Studies,
Institute of Science
Gitam University Visakhapatnam.
http://www.ecy.wa.gov/programs/wr/dams/guide.html :[Emergency Action Plans,EAP for Dam-Burst Scenario]
http://www.ecy.wa.gov/programs/wr/dams/failure.html : [ Dam Failures-case studies,USA ]
http://www.helenair.com/articles/2001/09/19/stories/headline/1a5.txt :[ Terrorists target Dams in USA?]
http://kfki.baw.de/fileadmin/conferences/ICHE/2002-Warsaw/ARTICLES/PDF/129C2.pdf : [ Asian Standards]
http://www.sscac.gov.in/p_maindam.html :[catchment :88,000Sq.km.Design flood:1 in 1000 years:85,000 cumecs.]
http://www.hydrocoop.org/Shall_we_forget_the_traditional_design_flood.doc :[ PMF Design Criteria adopted for SSP ]
http://www.icold-cigb.org/PDF/berga.PDF : [ Narmada historical record: peak flood of 71,000 cumecs in July 1994 ]
According to the web site :http://www.theepochtimes.com/news/6-6-11/42574.html,Dams while being very useful for providing water for municipal and industrial needs and power generation in many countries of the world,they are also very hazardous when they are not planned on scientific and eco-friendly methods.Since Indian Engineers are not given due weightage for their technical reports on Dam safety because of the excessive power exercised by the Bureaucrats in connivance with the vested interersts among the contractors and political lobby,the national economic and development interests are bound to suffer in the long run.In order to make the intellectuals take keen interest in safeguarding public interests,an attempt is made to present on how safety of Dams is reviewed in advanced countries so that Indians can learn from their successful examples.
A case study of Polavaram Dam proposed in Andhra pradesh is presented to show how our experts plan for Dams which are prescriptions for disasters.Browse through the following web sites for the purpose:
This web site presents ways of improper designs followed by civil engineers to design Dams and the consequential hazardous situations created by them and the measures taken to make them safe
Web below presents a Court Case on Dam Safety on PIL [ pages 9&10 on the role of Design Flood Criteria?]
"As the debate about the Three Gorges dam rages on, on June 1, E. Jingping, Secretary General of the State Flood Control and Drought Relief Headquarters and Vice Minister of Water Resources, said that the safety of reservoirs continues to remain a challenge and is a weak link in this year's flood prevention efforts. As of last year, an average of 68 reservoir dams collapse every year in China. He said, "The extent of casualties and economic cost from a dam collapsing possibly surpasses that of a natural disaster like a tsunami or a strong earthquake, and is no less damaging than a local war." At present, China has 85,160 reservoirs. From 1954 to 2005, a total of 3,486 reservoir dams collapsed ".........
In the light of the growing public demand to review the safety of Dams in almost all advanced countries in the world,India should not lag behind . Anattempt is made to present the case of Sardar sarovar Dam.
For Dam-Break Analysis made (See Table) it is found that the flood havoc due to Dam Break will be five times
[http://www.hydrocoop.org/Shall_we_forget_the_traditional_design_flood.doc [ most often between 2 to 5 timesSDF] more than the peak flood of 71,000 cumecs during July 1994 http://www.icold-cigb.org/PDF/berga.PDF which posed serious threat to life and properties of millions of people of Baroda and Bharuch districts. In fact when Narmada was under peak floods on 3-9-2002 the water level at Sardar Sarovar dam site touched 106 m elevation and it stood at 28 m at Garudeswar and 6.10 m at Golden Bridge in Bharuch. By the evening the water level at Bharuch touched the danger level of 24ft (7 m) by late Tuesday night. People living in low lying areas in villages in Ankaleswar, Jaghadia and Bharuch taluks and low-lying areas of Dabhoi and Chandod of Vadodara district and 30 villages in Narmada district warned by the District Collectors about the impending floods and assisted them for evacuating them to safer places. If such normal floods were posing a threat to the lives of thousands of poor people downstream of Sardar Sarovar the State Government must be prepared for gigantic disasters when more catastrophic floods either due to continuous intense cyclonic rainfalls as had occurred in Mumbai July 2005 due to global warming effects or due to dam break floods. Hence the Central and State Governments even at this stage must make serious attempts to avert such catastrophic floods by abstaining from further increasing the height of Sardar Sarovar dam and consider alternate methods for providing water supplies for Rajasthan and employ other energy sources like coal, oil or natural gas to produce more electricity.
The Supreme Court Judges are completely misguided by the Union Ministries of Water Resources and Environment and the state Governments of Narmada basin on the potential environmental hazards of the project because these Governmental agencies who have a responsibility to protect the safety of millions of people and the project are not raising the issues of Dam Break Analysis, Risk Assessment and Disaster Management plans which are the crucial components of the Environmental Impact Assessment (EIA) reports to be submitted to Union Ministry of Environment as per rules of the Environmental Protection Act,1986 and the Notification issued by the Ministry in 1994.The Two Judges of the Supreme court Anand.J and Kripal.J directed that the project proponents must satisfy the Environmental conditions to get fresh clearance for each 5 meter incremental increase in the height of the Sardar Sarovar Dam. In contravention of the Supreme Court directions of October 2002, neither the State Governments nor the Union Ministries are fulfilling their basic duties to get the Dam Break Analysis, Risk Assessment reports and Disaster Management plans that need to be prepared with the consent of the people who will be affected by the inundation consequent to a potential dam failure due to a maximum credible accident. Non-preparation of these reports amounts to a serious deficiency in the safety of the dam. Unless Risk Assessment is made nobody can grasp the need to look for alternate methods of going ahead with the project by making suitable modifications to make the dam safe for the people and the many industries located in downstream side of the project.
The supreme court can make a review of the project if only the petitioners, and the intellectuals with social responsibility as envisaged under article 53 A (g) of the constitution and the NGO leaders are willing to have the open mind to debate about the Environmental Hazards likely to arise due to increased levels of Extreme floods consequent to the rising global warming effects that caused the Mumbai Flood havoc of July2005. The seismic safety of the dam needs to be reviewed in the light of fresh eartquakes at Latur and Bhuj. Unless the socially responsible Indian Intellectuals insist on preparation of Dam Break Analysis and Disaster Management reports as stipulated under the Questionnaire for Environmental clearance for each 5 metre increase in rise in the height of the dam ,the millions of villagers likely to be effected will not come to know that this portion of Sardar Sarovar project intended for generation of hydro-power is nothing but their killer project since Pt. Jawaharlal Nehru has warned the Maharashtra state Government in 1963 that water alone can produce more food while alternate sources like coal and natural gas can be used for hydro-power generation in place of water . But does anybody among the political leaders or the decision making Indian Administrative Officers or the profit making contractors and the Engineers listen to such sane advice? Under the circumstances even if the supreme court has to take a fresh and second look at the project, just as Mrs.Indira Gandhi, the former Prime Minister directed the Union Government to have a thorough re-examination the Tehri dam project from the environmental angle the petitioners have to search for new facts to be presented before the Supreme Court to review the project to protect the right to life of millions of people in the down stream side of the dam. The supreme court must be informed that the Union ministry of water resources took in1991 the world bank Aid and completed Dam Break Analysis reports by 1999 for many dams in Orissa, Rajasthan and Madhya Pradesh to ensure the safety of these dams, besides suggestions for remedial measures, The court may perhaps question the Government why similar action has not been taken in the case of Sardar Sarovar project particularly when Risk Assessment and Disaster Management reports are mandatory under Environmental clearance notification of 1994 and when Union Ministry of water resources have established a Dam Safety Organisation [DSO] in the Central water commission in May 1979,as can be seen on page 32 of web site: http://wrmin.nic.in/editors-conference.pdf. [If necessary,To get access to this website.please copy it on google search and then click on the second option "containing the term'"]
It is seen from page 34 of the above web site that the Union Ministry of water resources asserts that in order to carry out Dam Break Studies and preparation of Emergency Action Plans and also to guide the various states in this new field of activity, the DAM BREAK ANALYSIS GROUP [DBAG] started functioning in Central Water Commission from November 1990 itself.
And yet with the all the required facilities including the World Bank special assistance for this specific purpose available at their command to get Dam Break studies conducted as per Law, the Union secretaries for the Ministries for Water Resources and the Environment chose to successfully refuse to discharge their basic function in preparing the Risk Assessment and Disaster Management plans for Sardar Sarovar and thereby misguided the Supreme court Judges, the prime minister and innocent Environmental and Human rights Activists on these environmental hazards. It is perhaps the fault of the intellectuals who failed to educate the general public of Baroda and Bharuch Districts, down stream of the dam about these relevant crucial problems of life and death that are evident from the comprehensive EIA on Sardar Sarovar Project Otherwise these potential victims of a hypothetical dam break will stop further work on Sardar Sarovar. Even the supreme court Judges are kept in darkness about these crucial relevant issues. That is where role of Ms. Arundhati Roy, Ms. Medha, Shri Iyer and other intellectuals becomes important as they can highlight these problems not only in Gujarat but in all parts of the country and the world at large.
After the International Committee on Large Dams realised that hundreds of dams collapsed in several countries during the past decades due to deficiencies in the design of spillways, faulty geological foundations, construction defects and human failures in operation and maintenance an International Technical Conference was held in New Delhi in 1979 on safety of dams. As a consequence of the recommendation made by this conference, the Government of India established an organizational structure in the Central Water Commission to plan for safety of dams in India. The Central Water Commission issued guidelines and procedures to be implemented by the states for ensuring safety of the dams. Under these guidelines the necessary Emergency Preparedness Plans must be prepared for all the damson the basis of the continuous evaluation of hydrological and seismic safety aspects. In the United States the Dam Safety Act was passed in 1972 and most of the states passed rules and regulations on the classification of dams based on the heights of the dams, the volumes of storage and their hazard potentials. http://legis.state.va.us/codecomm/register/vol18/iss14/f4v5020.doc
As per these guidelines the design criteria for the safety of the dams is mostly based upon the seismic potential of the site and the magnitude of the spillway design flood which again is entirely based upon the density of population in the villages and towns and industrial and agricultural developments downstream of the dam likely to be destroyed due to a hypothetical dam collapse. see pages 7 and 8 of Virginia state Regulations on Dam Design Criteria for safety of Dams implemented in United States as can be seen on web site: http://www.state.va.us/dcr/sw/docs/dsregs030804.pdf .
It is deplorable that while skilled experts in civil,structural,hydraulic and environmental engineers pool their scientific and engineering skills to finalise the design for a safe dam, it is unskillful legal experts that seem to dictate terms on the design of irrigation works like Major Dams. Much more surprisingly such risky and unscientific decisions are considered to be decisions that binding on the states whose citizens are unknowingly made to be subjected to a virtual death sentence for no fault of theirs. How can the Judges of the supreme court be considered to be right when they consider such faulty decisions of a tribunal to be right and then treat them as mandatory when they are based on wrong foundations.? While the right to life is upheld by the Constitution, how can the decision of a tribunal created by an Act of parliament be given overriding weightage particularly when the decision of the tribunal runs counter to the latest rules of the Environmental Protection Act,1986 under which Notification for Environmental clearance requires the preparation of Risk Assessment and Disaster management for river valley projects. In giving due weightage the supreme court must resort to invoking the principle of comparative consequences in deciding the case on increasing the height of Sardar sarovar
Most unfortunately in the case of the Sardar Sarovar project the Narmada water disputes Tribunal composed off eminent legal experts who have no basic fundamental knowledge about the complicated design of irrigation structures and their environmental impacts made a risky venture to decide on the complicated design aspects of the project including the height of the dam and the irrigation canals. Normally the judges of the Tribunal should have been content with the exercise of their just power for making equitable distribution in the sharing of Narmada waters between the basin states. The judges of the Tribunal fully know that in allocating the river water the first priority has to be given for Municipal water supply, the second priority for irrigation of agricultural fields for food production and only the third priority for hydro-power generation. For construction of the dam the proponents have to make a cost benefit analysis of the project which should include not only the benefits accruing from drinking and industrial water supply and agricultural production but also the costs involved in paying compensation for the loss of lives of millions of human and cattle population and industrial and agricultural products consequent to a hypothetical failure of the dam due to a maximum credible accident resulting from extreme flood events, earthquakes, bombing, terrorist attacks, construction defects and human failures. Without making such crucial risk analysis of the project the tribunal cannot come to a decision on the size of the project with respect to providing water for municipal and irrigation purposes for Gujarat. Similarly the tribunal could not consider the alternate possibility of making 1200 MW of power available to the states by using cheaper sources like coal and natural gas since hydro-power generation alone requires increasing the height of the dam beyond its useful limit because the bigger the height of the dam the greater will be the consequential economic damages due to a hypothetical dam failure. In fact the US experts sometimes find that the alternative choice of abandoning the proposed project may become a more economical and environmentally safe proposition than going ahead with the construction of a highly risky and economically damaging project. The tribunal miserably failed to present comparative costs of different alternatives to the project on lines similar to those followed in the case of Horsetooth reservoir (See the Word document attachment on Horsetooth dam) See the following website:
Even today in the light of 2 different Supreme Court Judgements, one by two judges Kripal.J and Anand. J and the other by a third judge Bharuch.J dt.18-10-2002 it is clearly stated as follows:
1) “ Even though there has been substantial compliance with the conditions imposed under the environmental clearance the NCA and the Environment sub-group will continue to monitor and ensure that all steps are taken not only to protect but to restore and improve the environment”
2) “The Environment sub-group under the Secretary, Ministry of Environment and Forests, Government of India will consider and give at each stage of the construction of the dam, environment clearance before further construction beyond 90 meters can be undertaken.”
If we examine the above 3 directions of the majority judgement there are contradictions among them. For instance when the process of according environmental clearance has to be given by the environmental sub-group that ensures not only the protection but also the restoration and improvement of the environment for every successive proposed 5 meter increase in the dam height, immediate action has to be taken to prepare risk assessment and disaster management plans which includes dam break analysis.
For obtaining such environmental clearances the dam proponents have to prepare the dam safety report including the dam break analysis, risk assessment and Emergency preparedness plans as specified under the rules of Environmental Protect Act and also the dam safety guidelines.
As per the above website of the Union Ministry of Environment and Forests the project authoriteis must submit an application for Environmental clearance for irrigation, industrial or other projects as secified under
As per the EIA notification dt.27-1-1994 as ameneded upto 13-12-200 Environmental clearance requires the project authorities to submit application in the proforma speicified in Schedule-II, accompanied by a project report which shall include an Environmental Impact Assesment (EIA) report, an Environmental Management Plan and details of public hearing as specified by the Central Government. This application form specified under Schedule includes preparation of reports for the following items also under the different serial numbers specified below:
The guidelines on dam safety sent by the Central Water Commission to the state Governments in 1986 includes an item on Emergency Preparedness Plans as can be seen from the following website:http://www.dams.org/docs/kbase/studies/csinanx.pdf [see item 9 on page 11 ]
If necessary, please copy the web site and use GOOGLE search engine to get at the correct information
The details to be furnished under the Emergency Preparedness Plans as per World Bank guidelines can be seen from the Website:
For the convenience of the reader the Emergency Preparedness Plans prepared under the dam safety Act 1972 including the inundation maps prepared for each of the dams in California is presented in the following website:
If this exercise is done it will be clearly evident that any further increase in the height of the dam that is mostly intended for the third priority of hydro-power generation which becomes highly risky in view of the lakhs of human and animal populations that will be killed within a day of a hypothetical dam failure due to a maximum credible accident even by a terrorist attack.[ http://www.helenair.com/articles/2006/09/11/helena/a01091106_1.txt ]
In the American Society of Civil Engineers (WRI Division publication of November 1978) on the case study of Teton Dam failure and the experiences in Disaster response (PP 275-279) were presented to illustrate the water resource related problems that arose as a result of the furious flood consequent to the collapse of teh Teton dam in Idaho, USA on 5-6-1976 and to encourage advance planning for response (Disaster Management) to similar potential dam collapses in the future. It is relevant to quote some passages from the above article.
SHOULD INDIAN EXPERTS AND GOVERNMENT NEGLECT SAFETY OF DAMS AND THE PEOPLE ?
Several dams in India collapsed due to faulty design of dams and their spillways due to many reasons including extreme floods caused by torrential rains during extreme weather conditions like low pressures, depressions and cyclones whose duration and intensity is increasing day by day due to global warming, extensive deforestation, high urbanisation and industrialisation and Environmental pollution due to apathy the Indian Meteorological Department unlike their counter parts in USA have not set up adequate rain gauge stations for estimating the peak maximum precipitation in different river basin catchments, making a difficult to compute the probable maximum flood at different places along the river courses. Hence the Indian Engineers failed to provide proper storages and spillways for several dams including major hazardous dams like Tehri, Sardar Sarovar, Indira Sagar and Polavaram dams whose designs have to be constantly reviewed on the basis of revised estimations of seismicity and floods consequent to Bhuj earthquake, tremors in southern states and the extreme Mumbai floods of July 2005. The Indian state and Central Governments must learnt from the experiences of USA in this regard as indicated below.
MARGINS OF FLOOD DESIGN SAFETY FOR US DAMS (500 YEAR OR 1000 YEAR FLOOD EVENT ?)http://www.permatopia.com/wetlands/dam.html
All of the Corps dams were designed and built with specific flood capacities. Current dam designs are based on Standard Project Floods. Standard Project Floods, as defined in the Corps Engineer Manual 1110-2-1411 (March 1, 1965) are floods resulting from the Standard Project Storm. In turn, the Standard Project Storm is defined, somewhat imprecisely, as the most severe flood-producing rainfall-snowmelt, depth-area-duration event that is considered “reasonably characteristic” of the drainage basin. Discussions with Corps staff in the Portland District Office indicated that the Standard Project Flood is approximately a 500-year flood event.
The Corp dams’ discharge design levels include the combination of spillway discharge capacity and reservoir outlet pipe discharge capacity. For example, for the Hills Creek Dam, the Standard Project Flood is 64,500 cubic feet per second. The maximum controlled discharge capacity of the dam is 151,760 cubic feet per second, or nearly two and one-half times the Standard Project Flood discharge. These data are included on the Hills Creek Project, Emergency Response Flowchart7. At discharges beyond the maximum controlled discharge capacity of the dam, the dam would be overtopped, discharges would be uncontrolled, and there would be a high probability of damage to the dam, with some potential for dam failure. The large margin of safety in the discharge capacity of the dam suggests that the Hills Creek Dam likely has the capacity to withstand floods at least as large as a 1,000 year flood event without expected damage. The other Corps dams have similar margins of flood design safety.
Moreover the Union Ministry of water Resources and the Union Ministry of Environment and Forests who have a duty to examine whether the detailed irrigation and hydro-power project reports must include dam break analysis, risk analysis, disaster management reports and Environmental Management plans as per the guidelines, rules and regulations formulated by them before giving permission for the projects but unfortunately these Governmental agencies are violating their own guidelines, rules and regulations and blindly giving clearnaces for the projects some of which are likely to be hazardous and counter productive in the long run. The experts of these Ministries must make genuine efforts to ensure safety of the projects and the people by learning from the experiences of their counter parts in countries like USA as cited in the following website: http://www.ecy.wa.gov/programs/wr/dams/guide.html
"No dam can be 100% fail proof and yet prior to this incident, it was almost impossible to imagine a circumstance where a major dam would fail. Because of the general public's willingness to accept almost without question the basic safety of dams, government agencies were not as prepared as they could have been for failure. Professionalas involved in dam safety programs should utilise the experience of Teton to develop procedures and guidelines for response to dam failure as have been done for other physical disasters".
"The consequences of a dam failure may be reduced considerably by proper planning and training.Even with the best design and maintenance there will always be the possibility of a dam failure. That possibility cannot be ignored".
"One of the advantages accruing out of dam break analysis is the identification of areas likely to be inundated downstream through the preparation of flood-inundation maps".
"The probability of a dam failure willnever be zero whatever the engineered safeguards, controls and margins of safety may be (Martin 1985) Hence it is important that while one may hope for the best one should not forget to prepare for the worst".
Basic responsibility of Ministry of Water Resources to undetake Dam Break Analysis for Sardar Sarovar Project:
Since the Ministry of Water Resources has already utilized the assistance of World Bank for examining the safety of dams in Madhya Pradesh and Orissa and the World Bank reports clearly indicated that the old designs used for major dams are highly unsafe.
The people of Gujarat must also be sensitized on this problem so that they can demand the central and state Governments to conduct dam break analysis studies for the Sardar Sarovar project to provide security for the safe functioning of the dam and to provide safety to the lives of the millions of people living downstream of the dam and also to the right to livelihood of lakhs of industrial workers employed in innumerable major and minor industries which will be destroyed in case of the catastrophic failure of Sardar Sarovar as already stated. The following website clearly indicates that it is a duty of the water Resources Ministries in Gujarat and the Governemtn of India to monitor the safety aspects of the dam at regular intervals by examining the hydrological and seismic aspects which are subject to continuous fluctuations based on changing environmental conditions such as global warming that caused the extreme flood havoc in Mumbai in July 2005. The state and central Governments have to prepare Emergency preparedness plans based upon dam break analysis , risk assessment and disaster management as envisaged by the CWC guidelines on Dam Safety.
Role of Ms.Arundhati Roy and Ms.Medha Patkar to educate the intellectuals and the people of Gujarat and other states on the damaging impacts of Sardar Sarovar:
The intellectuals, the non-governmental organisations, environmental activists and human rights activists must whole heartedly come forward to educate the Supreme Court judges, the Union Cabinet Ministers, the secretaries for Environment and Forests and the Water Resources, the Members of Parliament, the elected representatives from Gujarat, the industrialists of South Gujarat and the mass media on these crucial environmental impacts likely to be caused by each incremental increase of 5 meters in the height of the dam. I wish to make a personal appeal to the saintly personality in Mr.L.C.Jain whom I know since December 1988 when I made a presentation on the hazards of the Kaiga Nuclear power plant at the Indian Institute of Science Convention at Bangalore. I make a special request to Ms.Arundhati Roy and Ms.Medha Patkar not only to fight for the right to life of the people to be displaced in the catchment area but also for the right to life of millions of people downstream of the dam who will be instantly killed without a notice due to the sudden catastrophic failure due to a maximum credible accident during the night time of a rainy day during an intense cyclonic period when the rivers are full.
Gujarat has experienced very catastrophic earthquakes of very high magnitude on the Richter scale and the damaging consequences of Bhuj earthquake are similar to those caused by catastrophic Himalayan Earthquakes. The Sardar Sarovar project being located over a major fault zone surrounded by several lineaments, major earthquakes are bound to occur in the dam area during its life time when the dam may experience fissures similar to the ones experienced by the Koyna dam and result in its failure. The seismic co-efficient of 0.125g used for the design of the dam is unsafe because of the location of the dam in the rift zone on a seismic highway. The old concept of a seismic design used by civil and structural engineers for major structures has been shattered by the failures of major structures under Kobe earthquake of Japan. Since there are major dams upstream of Sardar Sarovar, the failure of one or more of these dams during torrential cyclonic rains may cause extreme floods at Sardar Sarovar when the dam may collapse, thereby unleashing extensive peak floods that will cause a major disaster for millions of people and industries in the extensive region covered by Baroda and Bharuch districts. Several dams were unscientifically designed by the engineers of Gujarat and the Central Government and some of them including Machchu-IIdam failed because the engineers failed to visualize that the highest observed floods could be more than the spillway design flood used by them as can be seen from the following website:
There is no guarantee that the Sardar Sarovar dam has been scientifically designed by using peak maximum flood likely to be experienced under the worst meteorological conditions influenced by the increasing global warming effects and hence Sardar Sarovar dam may fail due to extreme flood events also. Hence all attempts must be made to avert such a catastrophe that spells economic doom for Gujarat and the nation. Hence further increase in the height of the dam should be immediately stopped and fresh Environmental Impact Assessment (EIA) report must be prepared as envisaged by the Supreme Court by taking into consideration the latest seismological changes caused by the Bhuj earthquake and the Mumbai flood havoc of July 2005 caused by the crucial weather events due to the global warming effects. In the alternative the hydro-power sought to be generated by this project must be produced by using alternate energy sources like coal, oil and natural gas. The irrigation water supply for Kheda district must be provided by the Sardar Sarovar canal and the Mahi river water from Kadana dam thus saved must be supplied to Rajasthan by taking up a link canal so that extensive upland areas of North Eastern Gujarat districts may get the benefit of substantial drinking and irrigation water supplies. If necessary the annual water availability in the rivers can be increased by about 20% by warm and cold cloud seeding operations at a very inexpensive cost and the same can be supplied even to the most distant lands in Kutch and Saurashtra districts of Gujarat. Thus the modification of Sardar Sarovar project is essential to promote sustainable development of Gujarat and to promote the national prosperity on sound lines.
NWS –DAMBRK MODEL USED FOR DAM BREAK ANALYSIS FOR SARDAR SAROVAR: The U. S National Weather Service (NWS) initially developed DAMBRK program ( Fread, 1984) in 1977. Research has been ongoing in developing improvements in the DAMBRK model allowing it to have an increasing range of application ( Fread, 1989). The model has wide applicability, it can function with various levels of input data ranging from rough estimates to complete data specification, the required data is readily accessible and it is economically feasible to use with minimal computational effort on microcomputers.
DAMBRK model can be used to develop the outflow hydrograph from a dam breach and hypothetically route the flood through the downstream valley. The governing equations of the model are the complete one-dimensional Saint-Venant equations of unsteady flow which are coupled with internal boundary equations representing the rapidly varied flow through structures such as dams and embankments which may develop a time dependent breach. Also, appropriate external boundary equations at the upstream and downstream ends of the routing reach are utilized. The system of equations is solved by a nonlinear weighted four-point implicit finite difference method. The flow may be either subcritical or supercritical.
The hydrograph to be routed may be specified as an input time series or it can be developed by model using specified breach parameters (size, shape, time of development). The possible presence of downstream dams which may be breached by the flood, bridge / embankment flow constrictions, tributary inflows, river sinuosity, levees located along the downstream river, and tidal effects are each properly considered during the downstream propagation of the flood. DAMBRK may also be used to route mud and debris flows using specified upstream hydrographs. High water profiles along the downstream valley, flood arrival times, and hydrographs at user selected locations are the standard DAMBRK model output.
The DAMBRK model was developed by National Weather Service (NWS) so as to require data that was accessible to the forecaster. The input data requirement are flexible in so far as much of the data may be ignored (left blank on the input data cards or omitted altogether) where a detailed analysis of a dam break flood inundation event is not feasible due to lack of data or insufficient data preparation time. Nonetheless the resulting approximate analysis is more accurate and convenient to obtain than that which could be computed by other techniques. The input can be categorized into two groups.
The first data group pertains to the dam: (the breach, spillways, and reservoir storage volume). The breach data consists of the following parameters: T (failure time of breach, in hours), b (final bottom width of breach), Z (side slope of breach), hbm (final elevation of breach bottom), ho (initial elevation of water in reservoir), hf (elevation of water when breach begins to form), and hd (elevation of dam). The spillway data consists of the following : hs (elevation of uncontrolled spillway), Cg (coefficient of discharge of gated spillway), Cd (coefficient of discharge of crest of dam), Qt (constant head independent discharge from dam). The storage parameters consists of the following: a table of surface area (As) in acres or volume in acre-ft. and the corresponding elevations within the reservoir. The forecaster must estimate the values of T,B,Z,Hbm , and Hf . The remaining values are obtained from the physical description of the dam, spillways, and reservoir. In some cases Hs, Cs, Hg and Cg and Cd maybe ignored and Qt used in their place.
The second groups pertains to the routing of the outflow hydrograph through the downstream valley. This consists of a description of the cross-sections, hydraulic resistance coefficients, and expansion coefficients. The cross-sections are specified by location mileage, and tables of top widths (active and inactive) and corresponding elevation. The active top widths may be total widths as for a composite section, or they may be left floodplain, right flood plain, and channel widths. The channel widths are usually not as significant for an accurate analysis as the over bank widths. The number of cross-sections used to describe the downstream valley depends on the variability of the valley widths. They also depend on the availability of cross-section measurements. However, a minimum of two must be used. Additional cross-sectional data to be input by the forecaster according to such criteria as data availability, variation, preparation time etc. The number of interpolated cross-sections created by the model is controlled by the parameter DXM which is input for each reach between specified cross-sections. The expansion-contraction coefficients (FKC) are specified as non-zero values at sections where significant expansion of contradictions occur. But they may be left blank in most analyses. < namespace="" prefix="v" xml="true">
The development of breach to its final dimension caused the outflow through the breach over the spill way is at its maximum value of 3.5 lakh Cumecs for a storage of 0.95 M.ha.m near the dam 2.275 hrs from the beginning of breach. It takes further 21.6 hrs time for this peak flow to reach 130 Km away from the Sardar Sarovar dam and the peak flow at this section attenuated to about 1.25 Lakh cumecs. Similarly the peak flows, peak stages and their times of occurrence at different locations downstream of the river reach are presented in the tables and the graph.
In the present case study the dam break analysis is done for the Sardar Sarovar project proposed on river < namespace="" prefix="st1" xml="true">Narmada in Gujarat state.. In the down stream of the dam there are a number of towns and cities and several villages which might be affected in case the proposed dam bursts due to a maximum credible accident caused by floods, earth quakes and other causes. Hence a preliminary dam, break analysis has been carried out to create public awareness on the project and its environmental impacts. so that the social workers and intellectuals along with the industrialists in the Bharuch and Vadodara districts can come forward to grasp the basic fact that while the existing peak floods are already causing untold public misery and industrial damage at an enormous cost the additional incremental increase of the peak floods will be several times higher with the result that millions of people in the down stream districts of Sardar Sarovar dam will be washed away into the Arabian sea if the dam were to burst during the night hours in the peak rainy season when there could be torrential rains due to cyclonic weather conditions that persist for a considerable length of time as had happened in Mumbai flood havoc of July 2005. The articles byP. Ramachandran on Meteorology,"Lessons not Learnt" and "Clouds,Precipitation" in the August,13-26,2005 issue of Front Line Fortnightly Magazine , see we site : http://www.frontlineonnet.com/fl2217/fl221700.htm
,clearly show that Mumbai and Gujarat regions face extreme special weather phenomena including Mid-Trophic Cyclones[MTC]with a concurrent impact of cyclonic system from the East and a major Convective system from the West that result in Cloud Bursts as had been experienced by Mumbai not only in July 2005 but also in July 2006.Hence the Estimation of PMP[Peak Maximum Precipitation] and PMF[Probable Maximum Flood] particularly over Gujarat and Maharashtra[North of Mumbai] becomes difficult as the maximum cyclonic activity due to MTC is found at heights of 20 to 30 km coupled with very heavy rain-fall of over 300 mm per day.Moreover, the impacts of Global warming will have additive environmental impacts and hence the estimation of PMF becomes complicated and hence the Design of the Sardar Sarovar Dam and its reservoir from the safety and sustainable development angles has to be reviewed at intervals to plan for a reduction in the height of the Dam.
ALTERNATE PLANS THAT ARE SAFER:In order to avoid such a catastrophy alternate methods of supplying water can be implemented by limiting the height of the Sardar Sarovar dam to such an extent that even if the dam were to burst the degree of damage to millions of people and industries downstream of the dam in the rich industrial belt from Bharuch to Baroda can be minimized to the maximum extent. The engineers can suggest what size of the dam can be chosen so that while it promoters agriculture by utilizing the maximum amount of river water it would not cause unbearable economic loss to the state. The environmental impacts will be reduced by making alternate locations and sizes of dams for making full use of the Narmada water allocated to the state of Gujarat. Environmentalists and social activists like Ms.Arundhati Roy and Ms.Medhapatkar must come forward to make a detailed analysis of the problems created by increased height of Sardar Sarovar beyond its utility for agriculture and suggest alternative methods of making power available by using coal and natural gas so that hydro-power generation at Sardar Sarovar should not result in avoidable killing of millions of people and economic ruination of prosperous industries of South Gujarat. Infact the Narmada Tribunal composed of eminent judges should have restricted their duty to make proper allocation of the Narmada water among the basin states in a just equitable manner and since they are not specialists either in the field of sophisticated dam building or in the more complicated subject of environment for protecting the right to livelihood of millions of people, they should not have ventured to make a detailed structural design of the Sardar Sarovar dam and its irrigation systems which call for sophisticated scientific and engineering, technical skills and such decisions taken by non-experts on a technical topic should not have bound the hands of the supreme court judges who can extend their arms of law to reconsider these crucial issues of life and death from a humanitarian and national economic prosperity angles. Hence these topics of dam safety, risk analysis and disaster management for Sardar Sarovar project as envisaged under the environmental provisions under article 53 A(g) of the constitution , Environmental Protection Act (1986) and its rules and regulations promulgated in 1994 by the Union Ministry of Environment and the dam safety guidelines formulated by the Union Ministry of Water Resources for protection of public health, dam safety and national prosperity must be got implemented by the patriots of this country in the interests of sustainable development of the nation.
Back Water Curves extend the Range of Villages to be Submerged due to gradual Siltation
2.2 Upstream Effects
Sedimentation issues are not confined solely to the reservoir and downstream reaches. The backwater reach upstream of the reservoir can extend many miles upstream. The depositional environment immediately following implementation is confined to the delta region at the head of the reservoir. As this delta builds up, additional sediment is deposited in the upstream reach of river. The aggradation reach in turn raises the local water surface elevations, creating additional backwater and deposition even further upstream. This feedback mechanism allows the depositional environment to propagate much further upstream than the initial hydraulic backwater curve might suggest. Analyses of the Sardar Sarovar dam have indicated that the upstream river reach will experience aggradation of the river bed to a depth of 3.5 metres. This corresponds to an additional 20 villages being inundated in the 100-year flood, compared with the situation immediately following the filling of the reservoir (Bettess, 1993).http://www.dams.org/docs/kbase/contrib/opt175.pdf [pages:4 and 5]