POLAVARAM PROJECT WITHOUT SUBMERSION 

 ( WITH INLAND WATER NAVIGATION OF SEA GOING VESSELS)

T.HANUMANTHA RAO

Former Engineer-in-Chief, Government of A P and  United Nations (OPS) consultant

                                   (Proposals first appeared in Eenadu, A Telugu News Paper, Dt. 5-1-2008)

http://shivajirao32.googlepages.com/polavaram-0

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            POLAVARAM HIGH DAM VS LOW BARRAGES

 

NOTE

 

Polavaram Project directly benefits coastal Andhra Pradesh and indirectly Telangana and Rayalaseema regions, through water diversions. Early completion of the project is of paramount importance to the state. There is virtually no progress on the construction of the dam across the Godavary river, for the past over five years, mainly due to the objections of the upstream Orissa and Chattisgarh states. Apart from some permission, yet to be issued, by the Central Government, Court cases in High Courts and the Supreme Court are pending for several years. If the past experiences with the Orissa Government in stalling the construction of Head works of Vamsadhara stage II and Jhanjhavathi projects of Andhra Pradesh, for the past over 20 years is any guide, there is no hope for the completion of Polavaram high dam even in the next 20 years. It is in this context a technically and financially viable alternative giving same benefits of the dam, will have to be formulated, which would meet with the approval of the upstream states and incidentally also the consent of the people of Telangana region (submersion area), as well as the people, of the coastal areas (who have a risk of their lives due to the earthen 'dam break).

 

It is in this context a (technically and financially viable) solution was worked out by Sri T. Hanumantha Rao, former Engineer-in-Chief and U.N. (OPS) consultant about three years back (a gist of which appeared in the media on 5-1-2008). This alternative proposal relates to construction of three low barrages (similar to the one at Dowlaishwaram), in place of the high Polavaram Dam, at a lesser cost,(same storage) while retaining the canals, now being constructed, as they are. This alternative would give all the benefits of the Polavaram high dam, such as diversion of 80 TMC water to Krishna Delta, Industrial and drinking water to Visakhapatnam areas, apart from providing additional navigation facilities for sea going vessels, increased water facilities

for Godavari Krishna delta rabi season crops, more hydropower generation (than the high dam proposal), and all that with much lesser (about 25% ) area of submersion and with no risk. of life to 46 lakh people living in the delta region (due to "Dam Break").

 

Details of these alternative proposals are given in three parts. Part 1, describes the proposal, part 2 elucidates on doubts apprehensions and part 3 relates to comments on the 'Record of discussions' of the Advisory Committee appointed by the State Government. The State and Central Governments have the option of selecting the high Polavaram dam, which may not get completed even after 20 years (like Vaimsadhara Stage II and Jhanjhavathi projects) or the alternative proposal (with all the additional advantages as stated above) which could be completed within 3 years. In fact this would have almost been completed by now (mid 2010) had the advise given in 2007 was accepted then. Let us hope that wiser counsels will prevail now. THIS IS A BETTER TECHNICAL ALTERNATIVE TO THE HEAD WORKS OF THE PROJECT AND NOT AGAINST THE PROJECT.

PART-1

POLAVARAM PROJECT WITHOUT SUBMERSION – INLAND WATER NAVIGATION OF SEA GOING VESSELS                                                                                                                                  26.10.2009

(Proposals first appeared in Eenadu 5-1-2008)

T.HANUMANTHA RAO

Former Engineer-in-Chief, Government of Andhra Pradesh and

 United Nations (OPS) consultant

             (In continuation of this please see “tabular statement”, “doubts & apprehensions” & comments) 

1.                  Introduction:  The recent peak flood, that occurred during the first week of October 2009, in the river Krishna has given a clear indication of what the maximum peak discharges in the Indian rivers would be in the future.  Though the effects of global warming are not clearly established in physical terms, scientists (after analyzing the existing data) had concluded that the peak flood discharges in the Indian Peninsular Rivers, Krishna and Godavari would be increasing in the future. The peak flood flow in Krishna River on 3-10-2009, is reported to be 25.5 lakh cusecs and this is nearly 2.5 times than the peak flood of 10.6 lakh cusecs ever occurred in the past 100 years.  If the same phenomenon is predicted to the Godavari River at Polavaram Dam, certain startling issues would emerge.  The maximum flood discharge ever occurred in Godavari river during the past 100 years, was 33 lakh cusecs and the Polavaram Dam was designed for 36 lakh cusecs.  The Central Water Commission had determined the Possible Maximum Flood (PMF) as 50 lakh cusecs and the dam spillway was redesigned accordingly.  The recent floods in the Krishna river had created a scare in the minds of engineers and policy makers as to what would happen to Polavaram earthen (rockfill) Dam if such a 2.5 times increase in flood flow, namely 83 lakh cusecs occurs in the Godavari river.  The dam break analysis done by the National Institute of Hydrology (NIH) from Polavaram to Rajahmundry and by other scientists from Rajahmundry to the sea, indicated that when a peak flood of 50 lakh cusecs occurs in the river and the dam breaks, Rajahmundry area would be under 40 feet of water.  This would lead to the death of 46.15 lakh people (2001 census) in the Godavari Delta.  Such a global tragedy in waiting, should be avoided at all costs.  The 2.5 times increase in Krishna floods at Srisailam, has resulted only in a few hundred deaths, whereas the same increase in Godavari floods at Polavaram would result in a major catastrophe of a gigantic scale  Now a question arises – is it not possible to avoid all these risks and yet realize the same benefits of the Polavaram Dam through suitable technical alternatives, which do not result in huge submersions of villages, agriculture lands, forests etc.  Fortunately the answer is yes, in the case of Polavaram Dam.  A study of latest thinking in the world on this subject would be relevant.

 

2.                  Big storage:  The consensus of opinion evolved during the past decade of various international fora (including the World Water Forum), where engineers, environmentalists, social scientists and economists met, favoured the entire river length to be developed as a continuous series of stepped reservoirs, limiting the  water submersion to the peak flood flow section of the river.  Big storage reservoirs will have to be considered, only in special cases, such as flood storage (to prevent serious damages) carry over storages to meet drinking water requirements during drought years, and special hydro electric locations where adverse environmental impacts would be a maximum   Live storage in Polavaram Dam is 75 TMC, but it submerges 293 villages, over 1 lakh acres land 3731 hectares of forest land, all resulting in displacing about 1.6 lakh people.  All these can be avoided if a barrage is constructed in place of the dam.  Let us examine how the barrage proposal can give all the benefits envisaged in the dam proposal.  It has to be understood that this alternative is suggested only for the dam and not the project as such. In fact this barrage proposal aims at increasing the benefits of the project without causing substantial submersion of villages.  There is no doubt that Polavaram Project is very much needed for the development of all the regions in Andhra Pradesh.

 

3.                  Details of barrage:  The barrage suggested in place of Polavaram Dam would be similar to the one existing   at Dowlaiswaram across the Godavari river.  It would be designed in such a manner that the upstream water level at the barrage will be the same, as the water level on downstream of the barrage, irrespective of the flood discharge – whether it is 20 lakh cusecs or 33 lakh cusecs or 50 lakh cusecs.  The vent way of gates of barrage will be increased to correspond to the river flow cross section area during the maximum flood, by extending its length into the flanks and providing smooth approaches, and the whole process will be determined by hydraulic model studies.  There will be no siltation because the bottom level of gates that the entire barrage length will be kept at the bed level of the river, and the whole barrage will then function as scouring sluices when the gates are opened.  There will also be no back water curve effect, as there is no obstruction to flow, causing afflux.  In other words the ‘afflux’ would be limited to near zero, for all river discharges, eliminating the need for flood banks on the upstream side of barrage.  It is reported that a water level of 100ft above MSL was recorded at Polavaram, during 1986, when the recorded maximum flood at Dowlaiswaram was 33 lakh cusecs;  This water level will not get increased to a higher level even though the barrage is constructed.  Whatever natural submersion that will occur for a river discharge of either 33 lakh cusecs flow or 50 lakh cusecs flow will continue to occur and will not get increased even after the barrage is constructed.   In other words, there will be no additional submersion due to the barrage, and the entire flow will be limited to the high flood zone section of the river.  Some tribals have occupied certain places in the high flood zone area and are now residing there.  During high floods, they would vacate their houses and move to the higher areas, and again get back within a  few hours or days when once the floods recede. But when the barrage is constructed, the high flood zone will be filled with water for a few months and hence they will have to be rehabilitated.  The cost of this relief and rehabilitation will be  small.  In this proposal, there is no question of submersion of the 293 villages, forest areas, lands etc as in the dam proposal, and hence the construction of protective dyke walls in Orissa and Chattisgarh does not arise.  Salient features of the barrage are briefly explained.

 

4.                  Salient Features: 

o        Upstream and downstream water levels with 33 lakhs cusecs = 100ft (30.48m) above MSL.

o        Sill level of spillway gates = 34.5 ft (10.5m) i.e. bed level of river.

o        Height of spillway gates +65.5 ft (20m)

o        Top level of gates  = 100 ft (30.48m)

o        Top level of bridge on spillway = 3m free board from water level when 50 lakh cusecs flood flows through the gates.

o        Maximum Observed Flood in 100 years = 33 lakh cusecs

o        Possible Maximum Flood (PMF)  = 50 lakh/cusecs.  Provision is made in the design of gates for PMF exceeding 50 lakh cusecs also.

o        Storage in barrage upto top level of gates  = 36 TMC

o        Ayacut:  2,50,000 acres. Originally 7,20,000 acres ayacut was contemplated.  But, this got  reduced to 2,50,000 acres due to the actual availability at site.  As per the studies conducted by scientists of an International Organization (WWF), it was revealed that more than 4,70,000 acres within the ayacut area of the project, is already under irrigation through a) several major lift irrigation projects about to be completed, (e.g. Tatipudi, Pushkaram, Chagalnadu), b) Minor irrigation tanks completed   (c ) private ground water tube/dug wells  d) public tube well projects built by the State Irrigation Department Corporation, etc.  To think that the ayacut under Polavaram project would still be 7,20,000 acres is a myth and it would therefore be wrong to proceed on this basis.

 

o        Canals:  Gravity flow canals with FSL at 95ft can be planned on either side of the barrage.  But this would involve in excavation of new canals.  New gravity canals would need additional land acquisitions and capital costs over and above the amount of about Rs.2000 crores already spent on the two canals.  Though it is technically possible to divert 80 TMC  from Godavari to Krishna delta, it may ultimately be economical to use the canals now under construction, rather then excavating new gravity canals.  In such a case water will have to be lifted from 95ft level in the river to 133ft level of the canals. For a discharge of 12,000 cusecs (required for 2.5lakh acres, diversion of 80 TMC water to river Krishna etc.) and a static head of 38ft. (11.06 m) it would require 54MW and this can be met out of the 423MW hydro power that would be generated in the barrage.

 

o        Hydropower:  The Central Electricity Authority was holding a view that it would be possible to generate about 720MW hydropower in Polavaram dam as against 960MW proposed by the State Government.  On account of constructing a barrage (instead of the dam), the hydro power component, would get reduced to 423MW.  However, this can be improved to 1038 MW by constructing two  barrages on the upstream side – one at down stream of Bhadrachalam, and second across the Sabari river.  All these barrages will have submersions within the high flood zone of the river and village/forest/lands submersions will be minimal.  Thus, 78 MW more hydro power can be generated through these 3 barrages proposed, as alternative to the Polavaram dam.

o        Water Requirements:  Polavaram dam envisages a live storage of 75 TMC and for the sake of this, a huge submersion problem is being faced.  Incidentally, this live storage gets filled up in 8.5 hrs when the flood is 25 lakh cusecs.  Since the ayacut area got reduced from 7.2 lakh acres  to 2.5 lakh acres, there is no need to have  a big storage for the Polavaram project.  Just as the run of the river system at Dowlaiswaram is able to supply water for more than 10 lakh acres, the alternative barrage at Polavaram can easily irrigate 2.5 lakh acres as a run of the river system.  This is possible because, the cropping pattern is only for one crop and that too in the Kharif rainy season when there will be adequate flows in the river. However some storage would be needed to supply water for the Delta rabi season crops and Visakhapatnam water supply.

 

All other benefits that are envisaged in the Polavaram dam proposal can still be achieved through this barrage proposal. For example the inter basin  transfer of Godavari water to river Krishna to an extent of 80 TMC can be drawn during the rainy period of four months when there will be adequate flows in Godavari.  Drinking water and industrial water requirements throughout the year (24 TMC) can be met with, through the 36 TMC storage available in the barrage.

 

If for any reason at a later date, storage of water is needed for the project an utilizable storage of 79 TMC would still be available in these three barrages as against the utilizable live storage of 75 TMC in the original Polavaram Dam. The only main difference in the barrage proposal is that water has to be lifted from the barrage to canals over a static head of 11.6M   The same canals now under construction can also be utilized for carrying additional discharges (during the rainy season) to meet the requirements of further lift irrigation projects (Uttara Kosta Sujala Sravathi etc.) on the left and right main canals.  In such a case, additional pumping units will have to be installed in future,  at the barrage site, to pump this additional water for a static head of 11.6m.

 

5.                  Costs:   The latest estimated cost of Polavaram Dam (without canals) is stated in the media as 16,500 crores, out of which Rs.10,000 crores would be for spillway, rock fill dam and Hydropower civil works plus Rs.6,500 crores for Relief & Rehabilitation (R&R) of displaced persons.  On the basis of the recent estimate for the barrage at Kantalapalli on Godavari river (Rs.880 crores) the cost  of the above mentioned three barrages can be estimated as Rs.3,500 crores including the capital cost of pumping at Polavaram barrage. Thus the alternative proposal would lead to a saving of about Rs.13,000 crores apart from having the facility of quick execution and completion of the project much earlier than the Dam proposal.  Added to this, there will be no interstate or submersion problems.  More importantly there is no risk of “dam break”  of the earthen (rock fill ) dam  threatening the lives of 46,15,000 people, which cannot be ruled out as a figment of imagination in the light of the recent floods in Krishna river (when 2.5 times the maximum flood occurred).  When all the benefits of Polavaram Dam project could be achieved through the barrages at less than one third of the cost and without submersions, it requires a revised thinking on this project, especially in the revised context of the magnitude of the peak floods.

 

6.                  Interstate problems:  The barrages proposal will have no interstate problems with Orissa and Chattisgarh states, as there will be no submersion in those states when the alternative barrage proposal is implemented.  If the past experience with the Orissa state regarding Vamsadhara stage II and Janjhavati dam is any guide (stalling the projects for over 2 decades), it will not be prudent to assume that they will allow construction of Polavaram dam since it involves submersion of about 20 villages in their states.

 

7.                  Inland water navigation for seagoing vessels:  The entire length of (750 Kms) Godavari river will have to be converted into a series of continuous stepped reservoirs, one below the other by constructing a number of barrages, all along the river.  The author suggested this 15 years back and termed this as “Step Ladder Technology”.  Sufficient draft (depth of water) will be maintained all along the river, even in summer, to facilitate sea going vessels (ships upto 3000T capacity) to ply in the river.  This would be similar to St.Laurence river seaway (7 barrages), Tennessee (9 barrages) river Illinois (9 barrages), Missouri (10 barrages) and Mississippi river (27 barrages) in USA.  The entire Godavari river will be a storage reservoir with submersions limited to the high flood zone of the river.  A ship load of coal from Singareni can go to any Indian seaport like Tuticorin, Haldia, Mumbai etc and also directly to any other foreign country.  This is also called as Green Technology.  Similarly ships from other countries can ply in the Godavari river and reach any place all along the river.  Villages and towns along the river will get international connectivity as happened in the cases of US, Europe(Rhine-Danube linkage) and China (from the Pacific sea to Chungking through the 3 Gorges dam).  This will facilitate development of major and minor industries duly utilizing the mineral and human resources in the area.  Employment throughout the year is possible through navigation, Industries including mass mineral based units (e.g. coal, cement).  Water required for these units as well as hydropower can be made available to these units.  Any raw materials imported can be done at a cheap transport cost.  Likewise goods (including manufactured goods) can be transported to other places (including international) at a cheap transport cost.  Ultimately Andhra Pradesh can develop economically like parts of China, withstanding international competition by producing goods at competitive rates.  More important is the employment generation to the youth in this navigation and allied sectors and the disposable incomes generated, boosting the economy of the area, (through several chain reactions of development).  The economic development of US and Europe in the mid Twentieth Century was attributed to this navigation associated sectors, where nearly 70% of the workforce was employed, whereas only 15% of work force was employed in the agriculture and irrigation sectors.  Though Irrigation is important for food security, many people still wrongly think that eradication of poverty can be done by irrigating every acre of arable land.  All the irrigation projects in Andhra Pradesh are being executed for raising one assured irrigated crop during the rainy season.  This will give employment to the landless labour for about 90 days in a year.  They will have to go out to seek employment for the balance 9 months in a year.  This is the reason why poverty still continues among the landless labour (who constitute 50% of rural population) in the Krishna and Godavari deltas inspite of every acre in that area being irrigated.

 

In the case of Godavari river, inland water navigation for sea going vessels can be made possible through construction of 11 barrages as shown in the map in the vicinities of 1. Pedda Bellala, 2. Yellampalli, 3. Chinnur, 4 Suraram, 5. Kantalapalli, 6. Edira, 7. Dummagudem, 8. Bhadrachalam, 9. Sabari  and 10. Polavaram.  Out of this the items 2, 5 and 7 are now under construction.  Items 8, 9 & 10 will form part of Polavaram Dam alternative plan  as described above, under the para 5 ‘Costs’.  Thus there will be a need to construct additionally four barrages (items 1,3,4 and 6).  There may also be a need for a few more barrages for navigation and this can be determined after a detailed investigation.  The cost of the above 4 additional barrages, locks and hydropower (about Rs.6,000 crores) can be met out of the savings of Rs.13,000 crores (as mentioned above in para 5 ‘Costs’).  Grants available in the Inland Water Navigation sector in Government of India, can also be utilized for this navigation requirement as well as other works such as developing inland water ports, rail and road connectivity to such ports, construction of wharfs, godowns, warehouses, purchase of loading and unloading equipment (cranes) extensionof power lines etc.  Also there is a possibility by considering all the above development project as a “National Project”.  This is the stage when Andhra Pradesh will have to plan for total economic development all along the Godavari basin, revolving round the water sector, rather than limiting all the development only to one irrigation sector.

POLAVARAM LOW BARRAGE AREA – CAPACITY (Approximate)

(Note: This calculation is based on the areas given in the E.I.A. report. Correct capacities can be worked out based on areas @1m. Interval contours)

Sl. No.

Level m

Area

Km2 & M2

Average area  Km2 & M2

Height

m

Volume

m3

1

13.50

0

 

 

 

2

18.00

22.5 x106

11.25 x 106

4.50

50.63 x 106

3.

24.00

60 x106

41.25 x 106

6.00

247.50 x 106

4.

30.48

140 x 106

(interpolated)

100 x 106

6.48

648.00 x 106

 

 

 

Capacity @ 30.48

=

946.13 x 106 m3

or 946.13 x 35.316 x 106= 33.414 TMC

Storage @ 30.48 = 36.082 TMC (as per June 2007, Reported based on contours).

PART-2    POLAVARAM DAM V/S BARRAGES

Date: 28-11-2009

 

Sl. No.

Views and Doubts expressed by the Govt. Committee on 24-11-2009 as reported in the press on 25-11-2009

Remarks of the Author

1.

Storage at the alternate low barrage site at Polavaram would be 22.8 TMC with FRL 100 ft and out of this only 5 TMC can be used

1. As per the area capacity tables, storage at 100' level is 36 TMC and out of this 35 TMC can be utilised for pumping into canals, during the non flood season. There will be a slight reduction in this due to locations of U/s barrages. It is possible to utilise 33 TMC. There is no need to provide any dead storage, since water upto sill level i.e., bed level can be used.

2.

Due to siltation,  utilization of water and useful storages in barrages will be reduced.

2. The proposed barrages are not like others, where sill levels of weirs are raised (like Prakasam and Cotton Barrages) and intended to facilitate supply of water to canals. In Such cases siltation will occur. The alternate barrages will have sill levels at bed levels similar to scour sluices  and the regime of the river U/s and D/s is not disturbed. The vent way would be equal to the river cross section and the flows would be as per the open-channel flow hydraulics and not as per the weir flow hydraulics. (Ref: Ven Te Chou) The water profile levels will be same as with or without a barrage.

Thus the river section will be the same (i.e. with same bed levels) with or without a barrage. In other words, there will .be no bed load sedimentation due to the barrage. The Colloidal Clay settlement in the pond due to long storage will be washed down as turbid water during the next floods.

3.

Total storage in 4 barrages will be 53 TMC and only 33.5 TMC out of this can be utilised.

3. As explained in item 2, the full storages in the U/s barrages up to the bed level namely 35 TMC can be utilised without any limitations of Minimum Draw Down Level (M.D.D.L.). with skillful selection of sites, approximate F.R.L.s & Limiting Submersions it is possible to get maximum storage at a place in between Bhadrachalam and Kunavaram and another on Sabari.

Thus the total useful storage of 79 TMC can be obtained only in 3 barrages. (35+25+19) (e.g. Storage at Kanthalapally = 22.5 TMC)

4.

Cost of barrages would be Rs. 9,000 Crores

4. On the basis of cost of Kanthalapally Barrage prepared in details in 2008 - 09 as Rs 880 Crores, the cost of three barrages can be estimated at 3500 Crores.

As a comparison the cost of Polavaram spillway and rock filled dam (2004 - 05 rates) was Rs.1627 Crores including the surplus course. Selection of locations of barrages will have to be done to get economic designs. For example cost of alternate barrage at Polavaram was estimated as Rs. 3000 Crores. This is almost double the cost of Dam & Spill Way. Whereas it should be only be a fraction of this.

5.

As against 277 villages submersion in Polavaram dam, 128 villages will get submerged under the barrages

5. According to the submersion area tables of Polavaram Dam 30 Villages will get submerged with FLR @ 100ft. This includes a portion of the submerged areas under the upstream barrages also. Another 30 additional villages may get submerged under the two upstream barrages. The exact details will have to be worked out based on submergence area 1 m interval contour map and the F.R.L. s selected for the upstream barrages. The upstream barrages should have dykes in continuation or barrages such that the upstream floods may not submerge the Down Stream Areas.

6.

Power production in the 4 barrages will be 271 MW

6. Power production contemplated at the Dummagudem barrage is 310 MW. On the basis of this it is possible to produce about 1038 MW at the three barrages. However details will have to be worked out by GENCO.

7.

There will be 7.1 Lakh acres under Polavaram Dam and not 2.5 Lakh acres.

7. WWF Officials have made a realistic study of existing irrigated areas, MandaI wise in the Command area and came to a conclusion that only 85,330 Ha (2.1 Lakh acres) are available. for Irrigation. (Vide book on Prospectives of Polavaram) This is said to be due to a part irrigation. under Tatipudi and Pushkaram L.I. Projects, Yeleru Project, Minor Irrigation, G.W. (Public & Private) etc. , there is no need to give irrigation to areas already under Irrigation through G. W. Minor Irrigation tanks and L. I. Projects. There is a need to reconcile the figures of the Govt. and W. W. F. Officials. A much lesser storage than 75 TMC (As per the dam proposal) would be able to meet the requirements of the Ayact. G. W. & L. I. projects would need power and under this plea, it would not be prudent to abandon the existing infrastructure & supply water to these areas with gravity flow canals from Polavaram Dam.

8.

Orissa Government will oppose the alternative design

8. In fact they would welcome this, since there is no back water curve effect (due to storage or obstruction of flow). During the floods the whole length of river, flows to sea without any obstruction or storage anywhere. Also no villages in Orissa areas will get submerged.

9.

There is no navigation facilities for sea going vessels down stream of Dowleshwaram and hence the same need not be provided on the up stream of Polavaram Dam

9. Two or three barrages will have to be constructed Down Stream of Dowleshwaram up to the sea to facilitate the navigation of sea going vessels. This will be similar to what has already been done in St. Lawrence River (USA) where 7 navigation barrages were constructed from the starting of river (Lake Ontario) to the sea. The cost of these barrages will go to the Navigation Budget and not the Irrigation Budget.

 

       PART –2(contd..)                                                     

 

POLAVARAM DAM ALTERNATIVES: DOUBTS AND APPREHENSIONS

 

(To be read along with Author's Paper "Polavaram Project without Submersion"  tabular statement and comments)

 

1. AYACUT:- Andhra Pradesh Government proposals envisage an ayacut of 7.2 lakhs acres to be fed by the  left and right main canals by gravity. Dr Bhiksham Gujja, Scientist. W.W.F. and others, after a detailed study of the ayacut mandal-wise, determined that not more limn 2.5 lakhs acres ayacut is available (for gravity flow), since more than 4.7 lakhs acres are already covered under various other irrigation sources (vide, chapter 9 "Perspectives on Polavaram"). These irrigation sources are:

 

-                      Pushkaram and Tatipudi lift Irrigation (LI.) projects which  are having 2 Lakhs acres under the gravity command of Polavaram Canals (and 1.921akh acres outside the command)

-                      Yeleru Project Ayacut (Gravity Flow) = 0.67 Lakh acres.

-                      Minor Irrigation tanks, public (I.D.C.) tube wells, private tube wells, flowing wells (artesian) dug wells and others having more than 2.1 lakh acres in command.

 

Their report concludes that after deleting the above ayacuts, the remaining area to be irrigated under Polavaram canals by gravity will not be more than 2.5 lakhs acres. This is a very strong point for re-examining the whole Polavaram Project proposals. The State Government will have to reconcile these figures in the interest of the State, instead of sticking on to the figure of 7.2 lakh acres. The avowed reasons for considering the ayacuts as 7.2 lakhs acres are noted below.

 

-           "Pumpsets for lifting water from Godavary river to Pushkaram and Tatipudi main canals will be disbanded and their ayacut of 2 lakhs acres will be fed from Polavaram main canals, thus avoiding the pumping costs from Godavary. These pump sets will be used elsewhere and the main canals of the L.I. projects will serve as part of the distribution system."

 

-                      "Minor Irrigation tanks do not have assured water supplies and for this reason, it is preferable to supply to this ayacut also from Polavaram Canals."

-                      "Yeleru gravity flow ayacut of 67.000 acres will be tagged on to Polavaram gravity canals. as this ayacut lies within command of Polavaram Left Canal"

-                      "For pumping ground water through tube wells, dug wells etc.. it requires electric power and to avoid this, it is preferable to supply water to this ayacut also from Polavaram Canals.”

A brief study would be needed to examine the technical, financial and administrative aspects of the above issues. How far the above contentions are not tenable and valid are discussed below;

 

A) Pushkaram and Thatipudi L.I. Projects:

-           The average static head of pumping from Godavary river is 18 m and with frictional losses. the total head would work out to about 20 m. When compared to the Devadula L.L Project (on the same river Godavary, now under construction), the static head is 275m (from Gangavaram river site to Station Ghanpur) and with frictional losses along the long pumping mains. the total head would then work out to about 400m. The pumping head for Pushkaram and Tatipudi LI. projects will be about 5% of that of Devadula L.I. Projects and therefore. The power consumption for these two LI. project would be rather insignificant, when compared to the other major lift irrigation projects on the same Godavari river. To scrap both these L.I. projects, on the plea of power consumption would not be prudent for the following financial reasons:

 

-           Elsewhere in the State, lift irrigation schemes are not scrapped when gravity flow is found possible through another project taken up later on. These two L.I. Projects are of major category (not Minor or Medium) and also huge amounts are even now being spent on them to lift water and irrigate.

 

- The two lift irrigation projects Pushkaram and Tatipudi cannot be considered as temporary works till Polavaram Project takes shape, since all the component works are permanent and form durable assets. These are unlike temporary structures like Coffer dams (dismantled later on), dewatering pumpsets (removed after construction is over). Assuming that the pumpsets of the LI. Projects would be dismantled and used elsewhere, the civil works constructed such as intake well, approach  channel, pump house, mains etc. would all go waste.

 

- The contention that the main canals of these two L.I. projects would be used as a part of the distribution system is not technically sound. The main canals of the two L.I projects are contour canals, running parallel and very close to the Polavaram main canals. They need not be operated when once the Polavaram main canals function in case the ayacut is tagged on to Polavaram, and hence, they would become redundant.  A distribution system comprises of branch canals, taking off from main canals at an angle (or perpendicular) to the main canal, and runs along ridge lines. Similarly. Majors/minors take off from Branch canals and distributaries take off from minors, forming the entire distribution system. In this scenario, the main canals of the two L.I. projects would have no role. Thus in this scenario, the main canals of the two L.I. projects would have no role in the distribution system, when once the Polavaram canals take this role. Thus the amount spent on these main canals, including the cross masonry works, structures etc would all go waste".

 

-           Lift for the two L.I. projects cannot. be entirely avoided, even if their ayacut is tagged on to Polavaram canals.. 1.921akhs acres of ayacut, will have to be served by lifting only, as the same cannot be commanded by gravity by the Polavaram canals. The extra lift if these LI. projects are continued, is only at Godavary river, which is relatively minor as discussed above. On the plea of avoiding this lift, it is not financially advisable to allow all the huge expenditures incurred on civil works (canals, structures etc.) to go waste. Also, it would not be administratively acceptable, since large private lands" were already acquired to build these engineering works.

 

YELERU:- Ayacutdars of 67,000 Acres are not willing to tag on to Polavaram ayacut, since they get water for only one crop from Polavaram canals, whereas, they are now getting water for two crops under Yeleru project. Thus, there is no need to supply water to this ayacut of 67,000 acres from Polavaram canals.

 

Minor Irrigation (M.l.) Tanks:- The ayacuts under minor irrigation (M.I.) tanks is included under Polavaram Canals while calculating its ayacut as 7.2lakh acres. This seems to have been done on the plea that this ayacut is not having assured water supply, there is no precedent for such a procedure in Andhra Pradesh While localizing the ayacut under Sri Rama Sagar Project (SRSP), the ayacut under minor irrigation tanks was excluded. The same was the case with Nagarjuna Sagar and other projects. Polavaram project ayacut area is having much better rainfall than the SRSP ayacut, and hence the water resources for the tanks in this area, are more assured than the other projects. On the principle that no area should be served simultaneously by two separate and independent sources, the ayacut under M.I. Tanks will have to be deleted from the Polavaram project. The procedures followed in the other major irrigation projects in the state, will have to be followed in this project also.

 

"TUBE WELLS, DUG WELLS ETC; Ayacuts irrigated under these sources are also included under Polavaram Project. This is said to be for the reason of avoiding pumping costs and electricity consumption. Ground water can be utilized only by pumping and. this can therefore never be avoided. In fact the Polavaram Project report contemplates and encourages the usage of ground water, as a measure of utilization of total water resources in that area. Such usage of ground water, is also contemplated in the National water policy, relating to conjunctive utilization of ground water with surface water. It would therefore be a retrograde step to scrap these ground water extraction devises and provide water to these areas from Polavaram canals. It is thus necessary to delete the areas served by ground water, from the Polavaram project ayacut; and also encourage further usage of ground water in the ayacut (as proposed in the Project Report). When all the areas (mentioned above) are deleted, the ayacut under Polavaram project gets reduced to less than 2.5 lakh acres as mentioned in the article of Dr. Bhiksham Gujja et.al. The project proposals including the extent of storage of water needed at Head works, discharge capacity of main canals and distribution system, will all get reduced significantly, as the ayacut is reduced to one third i.e. from 7.2 lakh acres to 2.5 lakh acres. This means redesigning the project as per the existing realities. The reservoir working tables will also have to be revised, and correct and realistic storage required will have to be worked out.

 

2. GODAVARY DELTA:-  There are apprehensions (as seen in the print media reports) that Godavary Delta will not get adequate water if the alternative proposals are implemented. It is in fact the other way round. Since the ayacut of Polavaram project is getting reduced from  7.2 lakh acres to 2.5 lakh acres, (in the alternative proposals),  the Godavary Delta will get more water than what is contemplated under the Polavaram dam proposal (now about to be constructed). This is more so when more extent of live storage (79 TMC) would be made available in the proposed three barrages. The risk of dam break is not imaginary and when this occurs, the lives of 46.15 lakh people living in the Godavary delta and surroundings would be endangered. All the while, there was a thinking that when the dam is constructed strongly, it will never break, and hence this risk is imaginary. In this context, it would be relevant to study the huge flood that occurred in river Krishna (an immediate neighbouring catchment of Godavary river), recently in October 2009: As against the maximum ever occurred flood of 9.5 lakh cusecs (in the past 100 years) at Srisailam (and corresponding maximum discharge of 10.6 lakh cusecs at Vijayawada Barrage), a flood of 25.5 lakh cusecs had occurred at Srisailam, during this year in October (2009). This is 2.7 times more than the ever observed maximum flood. If a similar flood occurs in river Godavary, which is quite likely in the future, the discharge in the river would be 89 lakh cusecs (i.e. 2.7 x 33 lakh observed maximum flood in Godavary river). Such a possibility is very much real, and not a figment of imagination, as it already occurred similarly in the Krishna river recently. Climatologists who are watching “global warming” say that peak floods in Godavari river would increase in the future. Meteorologists and hydrologists have similar views and' hence caution is needed. Though the Polavaram Dam and spillway are designed for a Possible Maximum Flood (PMF) of 50 lakh cases, when a flood much larger than this occurs, water levels in the reservoir would rise above the Full Reservoir Level (FRL) of 45.72m, and may overflow over the dam causing erosion and ultimate breach of the earth cum rock fill dam. Also any increase in water level above the FRL of 45.72 would encroach on the free board and the same is not  permissible in the case of earth cum rock fill dams. This is because the wave action and the wave run up on the slopes of earth dam would  cause spilling and erosion  leading to a breach. The stability of the earth dam will get endangered when water levels rise above F. R. L.

 

It is good to start construction of Polavaram earthen dam with a firm conviction that it would be built very strongly and would never break due to any quality reasons. If. the recent experiences on the earthen dam constructed in the State are any guide, one cannot be so sure of this conviction. In fact, all the earth dams will be constructed only with such convictions. But, we see different results all over the world. The Earthen dams of two medium irrigation projects (namely Gundlavagu Project and Palem Vagu Project) constructed during the past four years in the State, have breached even without the designed maximum flood occurring. There are innumerable  similar examples of dam breaks throughout the world, especially with earthen dams, well before the occurrence of P.M.F. The recent  one in India was the Morvi Earth Dam (Gujarat) breach, which killed about  15,000 people. Earthen dams can also break due to reasons other than quality. That is why the recent international recommendation is to avoid, construction of earthen dams in the close vicinity of thickly populated areas. Polavaram earthen dam sits just upstream of an extremely thick populated area. Even though the Polavaram earthen dam  is designed for a P.M.F. of 50 lakh cusecs,  the possibility of dam break cannot be ruled out (vide UN & ICOLD Guidelines on E.I.A.)

             

There is an argument that when a flood of 89 lakh cusecs occurs in the river, the areas on either side of the Godavary river will any way get flooded (with or without the dam), and the population will get effected, since the protective flood banks are designed only for a maximum discharge of 36 lakh cusecs. But, there is a difference between a dam break and a natural flood increase. In the case of a Polavaram dam break, the stored water of 194 TMC along with the huge flood of 89 lakh cusecs will flow down below, as a gigantic wave, similar to the Tsunami wave. People will have no time to leave their habitats. If such a break occurs during the nights, 46.15 lakh people will have a watery grave within some hours of occurring of the dam break. With regard to a natural occurrence of 89 lakh cusecs, this would occur gradually over a number of days and people will have time to observe the same, vacate their habitations, and move to the designated higher grounds. It has happened similarly in Krishna Delta during the extraordinary floods that occurred in Krishna river in October, 2009. In other words the increase in water levels does not happen suddenly in a few hours (unlike the dam burst wave).  Earthen dams are susceptible for breaks (e.g. Kaddam Dam) and Polavaram case can therefore be considered as a calamity “waiting to happen”.

 

This alternative proposal is suggested primarily in the interest of  population  residing in the Godavary delta, especially in the light of the recent occurrence of Krishna huge flood of 2.7 times the ever observed maximum flood. As a matter of fact, this alternative proposal will have to be strongly favoured by the Godavary delta people instead of opposing it, since this gives all the benefits of. the earlier "Dam proposal" without any risk to their lives in future. This apprehension may be due to information gap about the alternative proposal. In the case of the alternative barrage proposal the huge incoming flood of 89 lakh cusecs will pass down the structure, as it is, without any obstruction, and hence there is no need to do any 'dam break analysis' (as there is no dam).

 

3. NAVIGATION:- The present Polavaram Dam design provides for a small navigation canal, going in a tunnel and is suitable only for small boats and launches. It is not suitable for sea going ships, which is possible only in the case of the low barrage alternative proposal.

 

4. NATIONAL PROJECT STATUS:- National Project status is for the project and not for the design. Such a status will facilitl1te flow of funds from the centre and this is a facility to reduce the financial burden on the State. The design can be altered at any time when it is felt that there are advantages. As such the barrage proposal is not a hindrance in obtaining ,National Project Status. It is argued that if the design is changed now, it will take time to get clearances from the centre and thus the project work will get delayed. Actually, there is no progress on construction of the dam during the past four years and the work is about to begin now. Construction of a barrage in place of the dam would take about  1/2 to 1/3 time, when compared to the dam. Thus even though it may take a few months to obtain the required technical clearances for the alternative proposal, the. barrage can be constructed much earlier then the dam. Also this proposal will be welcomed by the upstream states (Orissa and Chattisgarh) as there would be no submersion in their States, as against submersions in the dam proposals.

 

5. STORAGE OF 75 TMC:-Siltation, cost of barrages, submersion of villages, hydro power generation of alternative proposals:- These aspects are discussed in the tabular statement and the main paper. The calculations made by the Government and reported in the print media are wrongly made out, and they are not in accordance with the alternative proposals suggested by me. For example, I have suggested only three low barrages including the one at Polavaram and not four barrages. As explained in this statement there will be no reduction in hydro power and water storage, if the proposals are worked out as per my suggestions. The cost of the project will. get reduced' and the number of villages (submerged will get significantly reduced (to about one-fourth of the dam proposal), if the alternative  proposals are properly calculated as suggested, duly selecting economic sites for construction of barrages.

 

6. ANNUAL COST OF PUMPING:- Annual cost of pumping water in the alternate proposals:- It is reported in the media that this works out to Rs.100 crore per year. This does not reflect a correct understanding of my proposal detailed in my paper. Out of the hydropower generated in the low barrage of the alternative design (say 400 M.W), 54 M.W. would be utilized for pumping the Godavari water into the canals. Power produced is 'free since the hydro power system will be constructed under the Irrigation Budget. The maintenance expenditure of hydro power units as well as the pump houses are also met under the Irrigation Budget. Thus the supply of power to the pumping units is free. and it cannot be said that the cost of power per annum would be RS.100 crore. The price of power is not costed for the other major Lift Irrigation Projects in the State, involving very high lifts, such as Devadula, Kalwakurthi, Nettempadu, Handri-Neeva etc., It would not be therefore appropriate to adopt a different norm for this project. Even supposing that hydro power has to be costed notionally for comparison, (when the calculations are made based on my proposals) this would work out to RS.30 crore per annum and not Rs.100 crore,  when costed as per the rates fixed by the Electricity Regulatory Authority for hydro power namely Rs.1.50 per K.W.H. In real time this would be a notional profit to the Irrigation Department and not, an expenditure, as made out, since capital and maintenance costs of hydro power are borne under the Irrigation Budget.

 

7. BENEFIT COST RATIO:- As explained in the tabular statement, the cost of the three barrages, if properly designed as per selected economic locations (and not as done by the Government) would work out to Rs.3,500 crores. Assuming the R & R costs (to be worked out as per actual submersions), would be RS.1,500 crores (for the alternative proposal of much lesser submersion) and the cost of the canals and distribution system as RS.3,500 crores (same as in dam proposal), the irrigation component of that of the project (for the alternative proposals), would work out to Rs.8,500 crores. The total irrigation component for the 'Dam' proposal would work out to Rs.18,700 crores (Rs.6,700 crores for dam, spillway and power block-civil + Rs.6,500 crores (revised) for R & R + RS.3,500 crores for canal and Rs.2,000 crores for appurtenant works and connections). On the basis of ayacut considered as 2.5 lakhs acres, the per acre cost of the alternative proposal would be Rs.3,40,000/- per acre (Rs.8,500 crore / 2.5 lakhs acres) and that of the 'Dam' proposal would be Rs.7,48,000/-  per acre. Thus, the benefit cost ratio for the alternative proposal would be 2.2 times of that of the 'Dam' proposal.

PART – 3    POLAVARAM DAM

Comments On “The Record Of Discussion” Of The Advisory Committee On The Alternative Proposals For Polavaram Dam.

            1. The Details given in the Discussion Report (D.R.) of the Advisory Committee, are totally in variance with the concept and spirit of the alternative low barrages given by me on 26.10.2009 and subsequently in the tabular statement (28.11.2009), Clarifications and calculations (20.12.2009). One of the reasons for the gap appears to be due to the fact that the Officers who met me initially and promised to meet me, later on, along with the relevant plans have not met me. As a result a technically feasible, financially attractive and administratively superior design with far less submersions (& no human risk to 46 Lakh lives due to dam break Tsunami type wave), is made out as exactly the opposite. This is due to an inappropriate application of a technology which is in variance with the philosophy and concept of the alternative proposals (A.P). Technical details pertaining to these aspects and how the actual costs and submersion areas etc… would workout in the alternative proposals are briefly discussed below. The conclusions drawn in the DR on the ‘Dam break’ are not correct for the reasons explained in the author’s paper on ‘doubts and clarifications (para 2, part 2). It has to be therefore treated as a calamity in waiting.

2. Number of Low barrages: The Concept of the alternative proposals (A.P) is to obtain an usable (live) storage of 75 TMC at a number of low barrages, instead of at one place at Polavaram Dam, since the dam which among the other things involves in huge submersions as well as risks of dam break. The storages created in these low barrages will entirely be ‘Live’ since water can be drawn upto bed level (Similar to flow in an unobstructed river) and hence there will be no dead storage or MDDL, as provided in page 21 of the Government Discussion Report (D.R).There is no need to provide four prohibitively expensive barrages and obtain a storage of 222.225 TMC (Vide page 21 of D.R.), where as 75 TMC storage would be adequate (as contemplated in the original Polavaram Dam Proposal). These very big Storages and high F.R.L’s had contributed to the exorbitant cost of Rs.19,108.53 Crores (Page 18 of D.R.). If the Spirit and philosophy of alternative proposals are properly adopted by appropriate selection of Barrage sites, F.R.L’s, Storages, the cost of proposals would workout to Rs.7143 Crores and not Rs.19,108.53 crores as described in detail in the later Paras. Again very high water levels (F.R.L’s) than required were provided in page 21 D.R. and this resulted in a huge submersion of a total of 345  Villages where as the high dam at Polavaram original proposal would submerge only 276 villages. (Vide page 21 of D.R). To put it mildly the designs worked out in the D.R., lacks appreciation of the concepts & philosophy of the Alternative Proposals. It has to be noted that only three low barrages (including Polavaram) were indicated in the tabular statement and clarifications as against four calculated in the D.R. The proposal of Kunavaram barrage costing Rs.5,330 Crores and submerging 202 Villages (Vide page 21of D.R) has no place in the concept of the A.P , and has to be therefore deleted altogether. The Details of the Barrages as provided in D.R. and what these should be as per the concept of A.P are discussed below. As a result it is now shown, how the cost as per the Alternative Proposals (Rs.7143 Crores) would be lesser than the cost of Original Polavaram (Rs.8713.09 Crores) as well as Rs.19,108.53 Crores shown in D.R, Also the number of Villages submerged as per the A.P. would be 72 no’s as against 276 no’s in the original Polavaram Dam proposal as well as 345 shown in page 21 of D.R. Generation of Hydropower as per AP is 1038 MW as against 201 MW shown in page 61 of D.R and 960 MW of Original Polavaram Proposal. Any new concept will have problems in understanding in the initial stages and this alternative proposal is no exception to this.

3. Polavaram Low Barrage: Selection of site for a barrage is very important for technical reasons as well as economy. This is possible only after a detailed investigation is done, keeping an eye on various possible alternative sites and their relative costs. An improve site, though technically possible may result in the cost going up by two or three times more than an optimally selected site. The cost of this lower barrage built upto maximum flood level is depicted in the D.R as almost equal to the cost of a high dam provided in the original proposal. Such a strange phenomenon should automatically lead to investigation of alternative economical sites, for constructing the low barrage. In the case of this low barrage, the site of the old dam proposal was selected in the D.R. At this site the barrage would be unduly long (3077 meters, vide page 21 D.R). This can be reduced to one third (say 1Km long), by selecting a downstream site as indicated below. For the original Polavaram Proposal, Constructing, Concrete/ masonry dam and providing spill way, Crest gates on the top of dam are not possible in the river bed, since rocky foundations are not available at any reasonable depth in the river. As such earthen dam was selected for the river portion and spillway located on the right bank where rocky strata is available. In the case of a low barrage, since it will have to be designed as ‘Weirs on Sand’ principle (floating foundations), a suitable site on the downstream of the old proposal (at a distance of about 2.6 K.M) and immediately down streams of the surplus course can be investigated for the low barrage site. At this place, the river width from bank to bank is about 800 Mtrs and about 1 Km long barrage can be constructed at this place. The length and number of gates will have to be designed so as to get the required cross section area of the river under MFL conditions of 36 Lakhs C/s Discharge. If the river width is not adequate for this purpose, the structure will have to be extended on either side and suitable approaches provided on the upstream and downstream sides. 16.48 mtrs depth of gates were provided in page.24 D.R. This has to be increased to 20 Mtrs depth so as to get the required cross section area, economise the design and keep sill of gates at bed level.

                 Foundation raft concrete for the piers, will have to be designed so as obtain sufficient anchorage required for these gates. The bottom of gates will have to be kept at the average bed level, in order to facilitate drawal of water up to the bed level, (for Godavari delta Rabi crop.) In other words when gates are opened the river would be flowing down naturally as earlier, as if there is no obstruction. This stored water from top of gates upto bed level can also be pumped for the requirements of the Polavaram canals, during the non flood periods. There is no need to provide dead storage by keeping MDDL at 28.956, as provided in page.21 D.R. The assumption that water stored above this MDDL only (4.204 TMC) is available for pumping is not correct. For calculation of pumping during the flood period, the water levels are considered as varying from 28.956 and 30.48 in the D.R.During this flood flow period of over 4 months the water levels will have to be maintained at near FRL of 30.48, by suitably regulating the barrage gates and allowing the excess flows down the barrage. Thus it may be seen that there is no need to pump stored water, as long as there are flood flows in the river and the entire 169.61 TMC demand of Polavaram (Page 37 of final report June, 2007) during Kharif season can be pumped when the river is in floods and water is then available at near FRL’s.

           In the Polavaram Original Proposals, the Rabi Season Demands of Godavari delta and Polavaram canals were contemplated to be met through the yields (flows in the river) and 75 TMC stored water. In the Alternative Proposals also, a similar method will have to be followed. Stored water will have to be pumped from a level of 30.48 extending up to almost the bed level and to facilitate this, the suction foot valve will have to be kept at a level corresponding to the bed level in a depressed sump, so as to avoid vortex problems. The static head of pumping will then be increasing as the water levels fall from 30.48 M to about 11.00 M in the Pond. The quantity of water to be lifted from lower levels will be a fraction of the quantity of water to be lifted from higher levels and the actual power requirements to pump during January – May will have to be calculated on a weekly or fortnightly basis. The installed pumping capacities (HP) to pump large quantities of water for Kharif Season requirements (from higher water levels) would be more than the required capacity to pump relatively a fraction quantity of water during the Rabi season (from the lower levels in the pond.)

               The cost of alternative Polavaram barrage is estimated in page.21 D.R as Rs.3,415 Crores, almost the same as the original Polavaram dam proposals which comprise of a high earth cum rock fill dam, separate spillway, bridge, lenghtly surplus course over 3Km long etc..(Rs.3630 Crores). With proper selection of site for the Alternative Proposals, the earth dam in the river will get replaced by a gated structure and there will be no necessity for a separate spillway (similar to Kantanapalli and Dummagudem which are now under construction). In such a case, the cost of barrage as per A.P will get reduced to about ½ to 1/3 rd of the original Polavaram dam proposals (e.g. Cost of Kantanapalli barrage is Rs.880 Crores). The main cost will be due to gates of Size 18M X 20 M, Rs.650 Crores (based on figures given in page 26 of D.R) 4 rows of 12M depth piles for 1 Km length of barrage (1000 X 4 X 12 X Rs.5900) Rs.28 crores, Spillway bridge 1 Km long Rs.8 Crores (Page 27 of D.R), piers Rs.77 Crores (Page 27 D.R) and adding for all other items like aprons concrete, steel etc. (on the basis of Kantanapalli Barrage) Rs.637 Crores, the total cost of the alternate barrage would then workout to Rs.1400, Crores as against Rs.3415 Crores provided in page.21 D.R. The topographical problem of aligning off take canals on either side will no more be an issue in the case of the down stream site for the low barrages of A.P. Water can be drawn and pumped directly into the cisterns and the gravity canals can start immediately from the cisterns. There is no need to provide pumping mains on either side due to the advantage of plain terrain conditions being available on both the sides of the structure. The canals can take off directly from the barrage structure without any need for separate pumping mains.

A gross storage capacity of 21.944 TMC is indicated in the design of D.R (Page 21). As per the reservoir capacity tables (page 39, June 2007 Report) the storage capacity at the proposed FRL 30.48 (100 ft) is 36.082 TMC. Since the Kunavaram barrage proposal is not there in the A.P design, the interception of storage, through Kunavaram barrage does not arise. The interception of Storage due to Bhadrachalam & Sabari barrages as designed in the A.P, would be very low, since the river bed levels at these places will be close to the FRL of 30.48. If these interceptions in storage are considered as 1.082 TMC (to be actually calculated based on submersion area contour map) the storage available for usage would then be 35 TMC and not 4.204 TMC as provided in page.21 D.R. The reasons for this (as already discussed above) are that water stored and available up to bed level can either for drawn to the down stream side or pumped into canals and that there is no need to maintain an MDDL of 28.956. Gross and live storage capacities in the cases of Bhadrachalam and Sabari (Chatte Kunta) barrages were rightly shown as the same (vide Page 21 of D.R ) and the same concept will have to be followed for this Polavaram barrage also. villages that would be submerged under this barrage at FRL 30.48  are noted as 66 no’s in the D.R (Page 21) out of this 32 Villages are stated to be below FRL 30.48 M level and balance 34 villages above 30.48 M level and extending upto 42.50 M (Page 34 & 35 of D.R). villages situated up to 12 M above FRL are shown under the list of Submergible villages for the adduced reason that the ayacutdars lose approach to their fields due to water stored in the barrage. The villagers can be provided with detoured cart tracks to approach their fields and for this reason, they need not be asked to vacate their villages situated far above the F.R.L. As such, the number of villages that will get submerged upto F.R.L. 30.48 can be considered as 30 (vide Page 129 of June 2007 Report) and not 66 no’s as indicated in page.21 D.R.

4. Kunavaram barrage : As discussed in para 2 above this structure has no place in the design concept of Alternative Proposals. As such the cost of Rs.5330 Crores and Submersion of 202 Villages and other issues noted in the D.R will automatically get eliminated.

 5. Bhadrachalam barrage: In the D.R, the F.R.L of this barrage is provided as 55.65M in order to obtain a gross and live storage capacities of 41.83 TMC & 41.63 TMC, respectively, submerging 58 villages. There is no need to provide such high F.R.L and submerge so many villages since it is enough to obtain a storage of about 25 TMC for the purpose of Alternative Proposals. As such if F.R.L of about 50.75 (with 20 M depth gates) is considered for this barrage to obtain a storage of about 25 TMC, the number of villages that would then get submerged, would get reduced to 26 that is less than half proposed in page.21 D.R. The possibility of further reducing the number of villages under submersion by reducing the FRL to about 46.72M and                         extending dykes on either side of barrage upto high ground (preventing outflanking) will have it to examined. However this has to be actually worked out based upon submersion area contours. Appropriate level and location of barrage site will have to be worked out, so as to obtain a storage of about 25 TMC. Length of barrage is indicated as 1858 M in page.21 D.R. By an appropriate selection of site at a place either near the upstream kink or near the downstream kink, this length can be reduced to about 1100 M. Also for this purpose a site where bed level would be 30.50 can be investigated. The cost of this barrage with reduced F.R.L from 55.65 to 50.75 & reduced length would be about Rs.1200 Crores, as against Rs.2970 Crores provided in page.21 D.R

6. Sabari Barrage (at Rapala): As per D.R page.21, a barrage at chatte Kunta on Sabari river was proposed where bed level is 30.155. An F.R.L of 53.31 with gross and live storage of 17.75 TMC submersion of 19 villages and  length of structure as 800 M were Proposed at a cost of Rs.1180 Crores (Page 27 of D.R). The F.R.L of 53.31 will have to be necessarily reduced to 44.72 (i.e., 1 M less than FRL of Old Polavaram dam proposals. Any increase in F.R.L (above 45.72) is unthinkable at this stage, as it would attract interstate problems with the upper states. The alternative proposals should aim at solving interstate problems & not enhancing them and hence an F.R.L of 44.72 is highly desirable to gain acceptance of the upper states. The barrage site may be shifted to the down stream side, about half way between the state border and Kunavaram (say at Rapala), where the bed level may be about 26.72 M (18 M depth gates Polavaram FRL 30.48M)  and width of rivers is less. The exact location will have to be decided after a detailed survey.  Since the F.R.L is drastically reduced from 53.31 to 44.72 the submersible villages will get reduced from 19 to 0 within Andhra Pradesh (page.50 D.R). Also there will be no submersion of any village in the two upper states. It may be noted in this context that more than 17 villages would get submerged in the upper states as per original dam proposals and the main objection of these states for Polavaram project is on account of this. When site is shifted to the down streamside, some villages here would get submerged. The aim is to select an appropriate site, which gives storage of about 17 TMC with F.R.L at 44.72 and also limits the overall submersion of villages to less than 16. Dykes will have to be constructed on either side of barrage & taken up to high ground to prevent outtaking (as indicated in above para). The cost of such a barrage with 18 M depth gates can be brought down from Rs.1180 Crores to 900 Crores by adopting the above measures (such as reduction in F.R.L from 53.31M to 44.72 M and reduction in length)

 

6(a) Preventing Submersion Of Tribal Areas And Providing More Irrigation  For More Than One Lakh Acres In Godavari Basin:   In this alternative proposal, about 75% of the submersible agricultural area (about 1 lakh acres) of the old dam proposal, will not only be saved from submersion, but also can be provided with irrigation through the above proposed two barrages.  This is a great boon to the backward tribal area farmers, who face a threat of submersion as per the earlier dam proposal.  Water from these two barrages can be taken by gravity flow canals to irrigate the agricultural lands lying between the contours <6.00m and 30.48m.  Kharif season crops can be irrigated in this area using the flood flows of river Godavari going to the sea in the rainy season.  This will not adversely affect the supply of the required water to Polavaram project.  Exact area to be irrigated, will have to be worked out after ground surveys during the DPR stage.  Thus the alternative proposal would also benefit most of the submersion area of the old Polavaram proposal, while giving benefit to the coastal area.

 7. Summary of  Costs submersion and Power: From the above paras, it can be seen that the cost of the three barrages at Polavaram, down stream of Bhadrachalam & Sabari as per the Alternative Proposals, would work out to Rs.3500 Crores (1400+1200+900) as against Rs.12895 Crores Indicated in Page 18 of D.R . The total number of villages that would be submerged under these three barrages as per A.P would be 72 no’s (30+26+16) as against 345 shown in D.R and 276 no’s in original Polavaram dam proposal. The total usable storage under these three barrages as per A.P, would be 79 TMC (35+25+17+2 due to storage between old dam site and proposal down stream site at Polavaram) as against 75 TMC required under the original Polavaram Dam proposal.

         In the comparison of Costs (Page 18 of D.R) the cost of original Polavaram project was indicated as Rs. 8713.09 Crores and that of the A.P as Rs.19, 108.53 Crores. The Details of Alternative Proposals will have to be corrected as indicated below, incorporating the changes indicated in the above paras. Item I will get reduced from Rs.12,895 Crores to Rs.3500 Crores. Item 2 can be the same as per original Polavaram Proposals (Rs.940 Crores and Rs.1800 Crores), since the same amount of hydro power under Alternative Proposals would be generated. Thus there would not be any decrease in costs (as explained in the power calculations). Items 3 & 4 for R&R, LA & Forests (Rs.2343.09 crores) provided under original Polavaram proposals will get reduced to about ¼ th i.e., Rs.600 Crores in view of the submersion areas in A.P getting reduced to about ¼ th of the Original dam proposal. The item 5 regarding pumping mains etc.. Rs.1543 crores (Page 58 D.R) provided in A.P will have to be reduced to Rs.303 Crores as there will be no pumping mains as explained under para 3 above.

          As against 182 MW power required for pumping provided in the D.R, only 54 MW power is needed (as per calculations in A.P due to reduction in ayacut). For these reasons item 1 of the statement (page.58 D.R) will get reduced to Rs.60 Crores & Items 3 & 4 reduced to 243 Crores & thus a provision of Rs.303 Crores will be adequate for this. The total cost of Alternative Proposals including Hydro Power Component would then work out to Rs.7143 Crores (Rs.3500+940+1800+600 +303=7143) as against Rs.19,108.53 Crores provided in D.R. When compared to the original Polavaram Project Cost of Rs.8713.09 Crores, the cost of A.P. would be cheaper by Rs.1570.09 Crores. Since the realistic submergence cost is expected to be about Rs.6000 Crores, much higher than Rs.2343.09 Crores provided in the original proposal, the actual cost of Alternative Proposal would be cheaper by more than Rs.4000 Crores, when compared to the original dam Proposal.

8. Power Generation: It is mentioned in Page 60 of D.R that 201 MW Hydro Power can be generated in the barrages proposal under Alternative Proposal as against 960 MW in Original Polavaram Proposal. Details for this are not furnished. As per calculations appended, the peak power generation would be 1038 MW (Bhadrachalam 423 MW + Sabari 192 MW + Polavaram 423 MW). The peak heads at Bhadrachalam would be 20.27 M (50.75 – 30.48), Sabari 14.24 M (44.72-30.48) and Polavaram 20 M (30.48 – 10.48). These heads will be decreasing as the flood flow increases over a limit and virtually becomes zero under the Maximum flood flow conditions, since there will be no water level differences on the upstream and down stream sides at that time. For example if there is a flow of about 10 lakh cusecs in the river at Polavaram, water levels upstream of barrage would be maintained at about near FRL conditions of 30.48, and the flood  would be allowed to flow down through regulated opening of barrage gates. Depending upon the river cross section, slope etc., water level on the down stream of barrage would then rise (say from 10.48 to 16.48) and the head would get reduced from 20 M to 14 M. If the flood discharge gets reduced from 10 Lakh cusecs to 1 lakh cusecs, the hydraulic head would increase from 14 M to about 20 M. However there would be no hydro power generation, during the few days of maximum flood flows occurring once in 1000 Years. This is due to no afflux during those rare events, when all the barrages gates are fully opened. The actual power generation on a daily basis in a water year, will have to be calculated based on the discharges in the river. This is similar to Hydro Power generation calculations in a dam where water levels vary from MDDL (for power) to F.R.L.

To assume that it is not possible to generate power in a barrage during the flood period because there would be no afflux is therefore not correct, for the reasons explained above. Additional hydro power units can be added on either side of the three barrages, and more power generated at a later date.

9. Power Consumed for lifting water into Canals: - The power charges to lift water into Polavaram Canals will have to cover lifting of water required for diversion to Krishna basin, domestic and Industrial needs of Vishakapatnam area and supply of water to an ayacut of 2.5 Lakhs acres under Polavaram Project. These would be as per calculations given in the Alternative Proposals and not as indicated in the D.R. The reasons for reduction of ayacut from 7.2 lakhs acres to 2.5 lakh acres are discussed below. The reasons why cost of power charges would not be a liability on the project are also explained in these calculations (appended for ready reference). Pumping additional quantities of water for Uttara Andhra Sujala Sravanthi or any other such projects would be a change on those projects and not on Polavaram project as explained below.

10. Polavaram Ayacut: - In the clarifications given on A.P dated.20.12.2009, the manner how the ayacut would get reduced from 7.20 Lakh acres to 2.5 Lakh acres were elaborated. In the D.R it was mentioned that 75 TMC storage is essential for the purpose of irrigating 7.20 Lakhs acres under Polavaram Project and 10.20 Lakh Acres under Godavari delta (Kharif and Rabi seasons) etc. In the alternative proposals also, provision for this 75 TMC is made and there is no deduction in this. However for cost of pumping equipment and pumping charges, realistic ayacut (2.5 lakh acres) under Polavaram Project and all other demands (e.g., Krishna, Industrial, Godavari Delta etc.,) are retained without any reduction.

There is no need to delink Yeleru ayacut of 67,600 Acres from Yeleru project and supply water to this area from Polavaram canals, in order to utilise this extent of water for the proposed new ayacut of Yeleru project lying above the Polavaram Command. The existing system of Yeleru ayacut in Polavaram geographical command (67,600 Acres) can continue under Yeleru project, and water can be supplied to Yeleru ayacut above Polavaram Command by pumping water from Polavaram canals and the scheme can be designed accordingly. Polavaram left canal has adequate capacity for supplying the required additional discharge.

              The total ayacut of 2,77,234 Acres (Page 51 D.R) is shown as Vishakapatnam district ( 1,48,202 Acres),Krishna District ( 61,901 Acres) and West Godavari District ( 67,131Acres). This will have to be analyzed with regard to what extent of area is already under irrigation through public lift irrigation schemes, tanks etc.. where government funds were already spent . A Study has indicated that the area without any irrigation facility and where crops are raised under rain fed conditions would be less than 1.8 Lakh acres and that this much area only would need irrigation under Polavaram project. Considering that private lift irrigation systems (e.g. tube wells, dug wells etc.,) will have to be supplied water from Polavaram project and that M.I tanks ayacut in the command has to be deleted, this ayacut would get reduced from 2,77,234 acres to about 2.5 lakh acres. It may be noted that ayacut under M.I Tanks was deleted from the project Commands in the cases of Nagarjuna Sagar and SRSP. The Same procedure can be followed for Polavaram Project also.

              With regards to the existing lift irrigation projects covering an ayacut of 3,75,166 Acres (Page 51 D.R), it is mentioned that the “life of some of the existing L.I Schemes is already over and the life of  other schemes will be over by the time Polavaram project is completed” . It is also stated that “since they will have to be abandoned, there is a need to supply this ayacut of 3,75,166 Acres under Polavaram Project.” Pushkara, Chagalnadu and Tadipudi L-1 Schemes comprising of 3,23,126 acres do not come under this category to be abandoned since they were also taken up for construction along with the Polavaram project at almost the same time or slightly earlier. In fact these schemes are still under construction, partly completed and about to be completed. With regard to the other four L.I Schemes comprising of 52,040 Acres, there is no need to abandon them for the reason that their life is over and then supply water from Polavaram Project. Their life time can be extended by repairs and renewals where ever needed. Many of the present major lift irrigation projects under Jalayagnam are lift schemes & they cannot be abandoned after a life time of the pumping equipment of say 10 or 15 Years. By appropriate renewals, whenever needed their life times can be extended and brought on par with other major gravity flow projects. The cost of renewals will have to be included in the maintenance cost and would not form part of capital cost.

From the above discussion, it can be inferred that the Polavaram Project will have to Supply water to an ayacut not exceeding 2.5 Lakh Acres. With repard  to Uttarandhra Sujala Sravanthi, Rudramkota irrigation and other lift irrigation projects from Polavaram Canals (Page 59 D.R) the cost of pumping equipment and pumping charges for lifting Godavari water will have to be borne under the respective schemes, as they cannot be a charge on the Polavaram Project. They are not existing schemes and they would take shape only after Polavaram Project is constructed. They have to be designed on the basis of the available conditions in Polavaram project. Also this lift from Godavari river would be relatively minor when compared to the big lifts required to pump Polavaram water to much higher areas under these schemes. Hence these costs will have to be deleted for purposes of comparison. There is no need to abandon the existing L.I Projects as discussed above. Such an action would result in wastage of public funds, since the Civil works (Such as Pump houses, structures along pumping mains, immovable structures, cisterns etc…) executed at a high cost would all go to waste.

             The alternate proposal gives an added advantage to the existing Krishna and Godavari deltas since the saved water from Polavaram Rabi demands (due to reduction in ayacut), can be diverted to these deltas during the Rabi season.

            The most important advantage is that 46 lakh people in the Godavari delta can live safely, without any fear for their lives due to any future eventuality of ‘dam break’ which incidentally is a common feature for earthern dams in the world, even when possible maximum flood does not occur. A flood similar to the recent Krishna flood (that occurred in 2009) would pose a threat to the Polavaram earthern dam and would breach it, even though it is designed for maximum possible flood.       

11. Inter state aspects and approvals for Alternative Proposals: In Page 11 of D.R, it is mentioned that in the case of the alternate proposals, fresh DPR will have to be prepared and clearances will have to be obtained apart from fresh consultations and consent of the upper states and that all these would delay the project. The correct picture is indicated below. Since the alternative proposals are simple barrages, it may take 3 to 6 months time to prepare the Detailed Project Report and in the mean while all the required clearances can be obtained from the government of India. Upper States would gladly welcome the low barrages proposals as no villages in their states would get submerged. It may be noted that these states were stalling the Polavaram project for the past several years on the main ground that more than 17 villages in their states would get submerged under the original Polavaram proposal.  The alternative proposals would get completed much earlier than the dam since the structures are also simple & small. There was no progress on the construction of the dam for the past 3 to 4 years for one reason or the other. If the past experience of Orissa government in stalling the Vamshadhara St–II & Jhanjhavathi Projects for the past over two decades is any guide, there appears to be no hope for completing Polavaram dam as per original Polavaram in the near future. Orissa government has already taken up this issue to the Supreme Court and it is also reported that certain clearances are not yet given to Polavaram Dam. In the case of these alternative proposals which give the same benefits of original Polavaram dam, all these stumbling blocks would automatically get eliminated and project completed very quickly at a lesser cost among the other several advantages elaborated above. Even though it may take six months time to call for tenders for alternative proposals, this may have to be viewed in the present context of yet to call for ‘revised tenders’ for dam, spillway, power blocks etc…     

12. Navigation: - Though navigational facilities are provided in the original dam proposal (page 9 of D.R), this navigational canal has to be taken through a tunnel (about 1 km long) and as such small launches and boats only can ply. There is no scope for sea going vessels to pass through such small canals & tunnels. In the alternative proposals sea going vessels can be taken through the barrage locks and this would ultimately lead to the economic development of the whole Godavari area upto SRSP (750 km distance), similar to what happened in St.Lawrence River (Sea Way), Mississippi etc in the USA. Such economic development of Godavari basin through navigation of sea going vessels will once for all get deprived it Polavaram dam is executed as originally proposed, and it will then be a great loss to the nation.

                        POLAVARAM BARRAGE [ALTERNATIVES TO DAM] DESIGN DETAILS

  1. Discharges in canals (left & Right) in Kharif Season :

a)      Ayacut (Total) = 2.5 Lakhs acres @ a duty of 75 ac / cusec discharge =

2,50,000          =          3333 cusecs

     75

 

b)      Krishna Diversion in 120 days = 80 TMC

Q in 1 day        =          80        =          2 TMC

                                    120                  3

@ 1 TMC / day discharge                   =          11,574 c/s

2/3 TMC / day discharge         =          11,574 x 2/3 = 7,716 Cusecs

 

c)      Domestic & Industrial water

365 Days = 24 TMC

1 Day   = 24/365 TMC Q = 24/365 x 11574 = 761 Cusecs

:. Total Discharge in both the canals = a+b+c = 11,810 Cusecs

                                    Or 11810/35.316 = 334.5 Cumecs

 

(Note : during the non Kharif Season there will be pumping mainly for (c) requirement)

 

  1. H P of pump sets required for both left & right canals : –

F S L Left Canal = 40.54 m

 

Water level in barrage (Allowing 1 m lower level during 4 month flood season) = 29.48 m

:. Static head = 11.06 m

Adding Friction Losses @ 10 % = 1.10, total Head = 12.16 m

 

HP = 334.5 x 1000 x 12.16  x  100  (eff. of motor 95% x eff pump 80% = 76%)

                75                       76          

=          71,360 HP or 71360 x 0.746 = 53235 kw or 54 MW

 

 

  1. POWER CONSUMPTION FOR PUMPING FROM RIVER TO CANALS : –

 

-DATA

a)   Total max discharge in canals = 11810 cusecs or 334.5 cumecs

b)  Total head = 12.16 m ; HP = 71.360 ; KW = 53235 (54 MW)

c)   Maximum pumping would be in 4 months (120 days or 2840 hrs)

d)   In the other days of the year, pumping for Krishna delta and drinking water will be less and power consumed during this period can be considered as 30% of the peak power consumed in 120 days.

 

CALCULATION OF POWER CONSUMED:

 

K. W. Hrs consumed in 120 days or 2880 hrs = 54,000 x 2,880 = 15,552x10 (power 4)

 

K.W. Hrs consumed during the other days in the year (say about 30% of above)

     = 4,448 x 10 (power 4) OR

      = 20,000 x 10 (power 4) OR     2 X 10 (power 8)

Cost at Rs. 1.50 per unit = 2 x 10 (power 8) x 1.5 = 3 x 10 (power 8) or Rs. 30 Crores

                                                                                         

Thus, the annual notional power consumption cost = Rs.30. Crores. This would be a notional profit to the irrigation Department, as hydro power is produced with capital and maintenance cost borne by the irrigation Department.

 

  1. POLAVARAM LOW BARRAGES – HYDRO POWER GENERATION

 

  1. Barrage D/s of Bhadrachalam:

Q = 1,00,000 c/s or 2832 cumecs on an average for peak power

H = 20m (water level differences between U/s and D/s 50.75 – 30.48 = 20.27 or 20 m). M. W = cumecs x Head/ 75 x eff x 0.746 = 2832 x 20/75 x 0.75 x 0.746 = 423 MW

Very large discharge axial flow turbines will have to be used.

 

  1. Barrage across Sabari; Q = 65000 c/s or 1841 cumecs and H = 14 m; (44.72–30.48):14.24 or 14 m. MW = 1841x14/75 x 0.75 x 0.746 = 192 MW

 

  1. Low barrage at Polavaram; Q = 1 lakh c/s or 2832 cumecs & H = 30.48-10.48 = 20m. M.W = 2832x20/75 x 0.75 x 0.746 = 423 M.W

 

  1. Total Hydro power = 423 +192+423=1038 MW