Prof.T.Shivaji Rao, Director, Environment, GITAM University, Visakhapatnamhttp://tshivajirao.blogspot.com/2010/06/polavaram-dam-design-engineers-mistakes.html
(The author worked as an Expert Member of the Environmental Appraisal Committee of the AP state Government to prepare the environmental impact report for the Polavaram dam (Indira Sagar project) in May 1985. Later he worked as an Expert Member of Environmental Appraisal Committee for Irrigation Projects of Union Ministry of Environment in 1989)
Videos on dam collapses in different countries to show that dams often burst to cause havoc.
http://www.youtube.com/watch?v=KEdM6Ys6spA&feature=related (Hoover dam burst)
http://www.youtube.com/watch?v=65D_E5SQqbo&feature=related (Dam burst animation)
http://www.youtube.com/watch?v=9_61-wGFlcc&feature=related (French dam breaks 1959)
http://www.youtube.com/watch?v=KEdM6Ys6spA&feature=related (Teton dam burst)
http://www.youtube.com/watch?v=u2beeXgvQlk&feature=related (Teton dam burst story)
http://www.youtube.com/watch?v=kIeNM8cm6J8&feature=related (Baldwin dam burst)
Dr.K.L.Rao warned in May 1983 that Polavaram design is defective and will fail:
Dr.K.L.Rao, the most eminent irrigation engineer, a former chairman of the Central Water Commission (CWC) and a former Union Minister for Irrigation and Power warned that Polavaram dam as designed is defective and it will not work (See Indian Express and Andhra Prabha, Vijayawada editions of 30th April, 1983.copy enclosed in website )-->
Dr.K.L.Rao said that for handling 36 lakh cusecs of peak flood of Godavari while cotton barrage was provided with a spillway length of about 12,000ft the modern engineers provided in the Polavaram dam a spillway length of only about 2000ft[3,000ft.]. For the Prakasam barrage over Krishna river a spillway length of morethan 3,000ft. was provided to handle the peak dischargeof 12 lakh cusecs. Any person with a commonsense expects that when compared with spillway capacity provided for the barrage over Krishna river the polavaramproject which handles 3 times more flood should have proportionately 3 times more spillway length amounting to more than the width of the river3,000ft. and for the cotton barrage they have provided a spillway length of about 3,000ft. Consequently Dr.K.L.Rao said “It was simple arthmatic to understand that the Polavaram design would not work” and it simply means that the Polavaram project is unsafe hence it is bound to collapse.Fordetails of the figures on the sizes of the spillway please see the diagrams at the end of this page.
http://sites.google.com/site/profshivajirao/polavaramdam-6 (See items 13 and 14) Eminent Engineers like J.Raja Rao, T.Hanumantha Rao and Dr.K.Srirama Krishnayya warned about the damaging impacts of the project. See website and Part-2, Godavari Delta item)
Reasons for impending failure of Polavaram Dam, killing 50 lakhs of people:
A.P.State Engineers insisted that unless the Full Reservoir level of Polavaram project is fixed at +150ft. Mean Sea Level, they can not transfer 80 TMC of water into Krishna river to enable Karnataka and Maharashtra to utilize 35 TMC of extra water from Krishna river CWC warned that during 1966 floods touched +153ft at Konta /Motueven without Polavaram dam and hence the Interstate Agreements of 1978 need to be modified. At peak floods, Motu/Konta will attain flood levels of +168ft with out the Polavaram dam and +174ft with Polavaram dam. So flood protection embankments were suggested to prevent submersion of lands above 150ft level at Motu/Konta in Orissa and Chattisgarh. Since AP State mentioned that a barrage will be constructed at Polavaram CWC agreed for spillway design flood of 36 lakh cusecs in 1979-80. But the devastating floods of 35 lakh cusecs occurred in Godavari in August 1986. Peak floods of 28.5 lakh cusecs in August 2006 caused flooding of 370 villages and the resulting catastrophe opened the eyes of the CWC to reviewthe peak flood potential. Consequently CWC revised the PMF to 50 lakh cusecs only in September 2006 and directed the AP State to revise the design of Polavaram. But the AP State used the old figure of 36 lakh cusec flood for preparing reports on spillway design, back-water afflux, submersible areas, forests and villages, Rehabilitation and Resettlement Schemes, EIA Reports including Dam-Break Analysis and Disaster Management and cost-benefit analysis and obtained clearances from Union Government by October 2005 itself. Since Bachawat Tribunal was also based upon this peak flood of 36 lakh cusecs, the Orissa and Chattisgarh states are arguing that Bachawat report is not valid as the peak flood has been increased from 36 lakh cusecs to 50 lakh cusecs and consequently the areas of submersion in their states will rise substantially at a time when their lands have been fully developed during the last 30 years and the change in the socio-economic conditions do not permit them to allow submersion of more such highly developed lands due to construction of Polavaram dam. Hence they filed cases in the Supreme Court for modification of the Polavaram dam in such a way that lands and villages in Orissa are not flooded due to backwater afflux consequent to construction of Polavaram
Moreover the AP state and CWC have under-estimated the Peak flood for Polavaram by using a low value of 50 lakh cusecs. In fact, another technical wing of the Union Ministry of Water Resources known as “National Institute of Hydrology” at Roorkee that prepared the dam break analysis report (at the request of AP State Government for incorporation in the EIA report for environmental clearance) suggested an inflow design flood of 60 lakh cusecs as per standard methods.-->
The experts of NIOH, Roorkee also observed that for a catchment area of 83,000sq.km for Hirakud dam the revised inflow design flood was recalculated at about 70000cumecs due to world bank financial assistance on dam safety granted to Government of India. By comparing the peak flood in the neighbouring Hirakud catchment area the inflow design flood for about 2 lakh square km of intercepted catchment for Polavaram dam was correspondingly estimated at 1,70,000 cumecs and the same was used for dam break analysis for Polavaram in June 1999.AP state mentioned that the design flood of 36 lakh cusecs is based on 500-year return flood. Subsequently it said that it has updated the value of the maximum flood on 10,000-year return flood and placed it at 50 lakh cusecs while the standard monographs place it at double the value of 500-year return flood which works out to 72 lakh cusecs. If we consider the standards used for Sardar Sarovar (a neighbouring catchment area) the extreme flood to be expected at Polavaram will be about 80 lakh cusecs.
-->Central Water Commission estimated 1 in 1000 year flood at 87,000 cumecs for a catchment area of 88000 sq.km for Sardar Sarovar dam and for the neighbouring catchment of Polavaram dam of about 2.16 lakh intercepted catchment the 1 in 1000 year flood is estimated at about 75 lakh cusecs and naturally the Probable maximum flood equivalent to 1 in 10000 year flood is bound to be far higher. If the impacts of cyclones due to climate change and sea surface temperature increases the flood intensity is estimated by scientists to increase by another 20%. Under these circumstances and for various causes normally cited for failure of embankment dams the Polavaram earth and rockfill dam is bound to collapse resulting in the death of about 50 lakhs of people downstream in East and West Godavari districts, causing collosal economic losses amounting to more than 1 lakh crores of rupees by making the Bhopal disaster fade into insignificance. Such manmade disasters will promote poverty and not prosperity of the people. Moreover therecould be sudden releases of floodsfrom dams upstream like Balimela, Machkund and Kolab in Orissa and Sriramsagar in Andhra Pradesh and Jaikwad in Maharashtra which spill waters from the reservoirs during cloud bursts to safegurard the safety of their own irrigation projects.
In addition to the peak flood of 50 lakhs cusecs estimated by the CWC and AP State engineers the standing water of about 194 TMC (Thousand Million Cubic ft.) will suddenly change into active flood flow of about 24 lakh cusecs which makes the outflow as 74 lakh cusecs on the down stream side of Polavaram. Hence a dam at Polavaram adds to the serious damaging flood impact and hence a safe barrage project is always preferable than a dam at Polavaram location.
If fore warnings from experts cannot forearm the people and their elected representatives in state Assemblees and Parliament, the health, national economy and the right to life of people is bound to be doomed and future generations will not forgive us for our sins of commission and omissions. we have to think and act in time to harness the waters of river Godavari for the benefit of the people of Andhra Pradesh by modifying the dam into safe barrages project. Let us examine the obstacles to the project and overcome them in a democratic way to ensure prosperity of the farmers.
Orissa High Court Order, a practical obstruction to the project:http://www.dowrorissa.gov.in/AnnualReport/WR_AR08-09.pdf (see pages 95-97)
During 2005 the AP State Government obtained partial environmental clearance for the project from the Union Ministry of Environment and Forest on 25-10-2005. Subsequently a former M.L.A.Mr.Lakshman Munda from Orissa filed a writ petition against the Hazards of Polavaram project in Orissa High Court and the Court passed a Judgement in March 2006 stating that Polavaram dam should not cause submersion of any lands/villages/areas in Orissa State and this order was accepted by the Union Government . Consequently AP state Government was asked to implement the High Court Order. Soon AP State Government also accepted Orissa High Court orders and agreed to avoid submersion of lands in Orissa and Chattisgarh by constructing 30km long embankment dam walls of 10 meters to 15 meters height in Chattisgarh and similar embankment dam walls in Orissa to avoid submersion of lands at a cost of Rs.700 crores.
No Clearences from Central Electricity Authority & Ministry of Environment
The Environmental clearance for this project has not been given by the Union Ministry of Environment which stated that unless the AP State conducts a public hearing in Orissa and Chattisgarh as per the regulations of the Environmental protection Act,1986 and obtain their consent for this project they cannot take up supplementary Polavaram project for second Environmental clearance. A.P.state is not working to get this clearance. By modifying the Polavaram dam into a safe barrages project to satisfy the needs of Orissa http://www.indiawaterportal.org/printpdf/post/2781
Similarly the Central Electricity Authority also has not given clearance for this project for execution of the 960MW hydro-power plant as a major component of this project
Impracticable clearances by Ministry of Water Resources & Planning Commission
But unfortunately the CWC and the Technical Advisory Committee without receiving these crucial clearances for Polavaram project have recommended to the Planning Commission for investment clearance. The cost of this project is estimated at Rs.16,000 crores by the time of its completion.
Polavaram Dam collapse will kill 50 lakhs of people living downstream of the dam
In case this dam were to collapse due to peak flood, earthquake or defective workmanship or human failure the wall of flood that surfaces will kill 50 lakhs of people living in both the districts of Godavari delta, downstream of the dam. Moreover about 3223 ha. of reserve forest will be submerged and a substantial area of Papikonda wild life sanctuary will be adversely affected in Andhra Pradesh and some more forests will be submerged in Orissa and Chattishgarh. This submersion can be substantially avoided by modifying the Polavaram dam into a barrages project while retaining the same economic benefits as contemplated by the original project.
Alternatives to killer Polavaram dam are the safe barrages that cost less:
But there are very good alternative proposals for this Polavaram dam to obtain the same economic gains by construction of 3 barrages on Godavari as proposed by an eminent former Irrigation Chief Engineer of Andhra Pradesh , Sri.T.Hanumantha Rao who is also an International consultant on irrigation projects and copies of this proposal are enclosed. While the Polavaram dam project costs Rs.16,000 crores, the Barrages project costs Rs.7,000 crores.
Governments must be advised to debate and act on these alternate barrages proposals
People must advise the Union Ministry of Water Resources, Chairman, Central Water Commission, Union Minister for Environment and Forest, Union Minister for Tribal Affairs and Union Minister for Water Resources and the Prime Minister to consider the alternative proposal which confers more advantages than the original project in terms of economy, safety and protection of the health and welfare of the people of Godavari delta. http://www.sandrp.in/drp/feb-Mar2006.pdf
Awareness among people by mass-media on alternate proposals is essential
The alternate proposals to Polavaram dam are presented in the websites to the mass media which as the Fourth Estate has a great responsibility to work in the interests of safeguarding the health and welfare of the people and the National economy by advising the Government to take up developmental projects without destroying the environment.
The author has taken up this work not only as an expert in the fields of environment and irrigation but also as a responsible citizen under Article 51 A(g) of the constitution of India.