POLAVARAM DAM VERSUS MULTIPLE BARRAGE
T.Hanumantha Rao and T.Shivaji Rao
(Contentions raised by AP State Government experts on the article on Polavaram project without submersion by Sri.T.Hanumantha Rao and the clarifications thereon)
Question No.1: It is contended that Storage at the alternate low barrage site at Polavaram would be 22.8 TMC with FLR 100ft and out of this only 5 TMC can be used.
Answer: As per the area capacity tables, storage at 100’ level is 36 TMC and out of this 35 TMC can be utilized 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 utilize 33 TMC
Question No.2: It is contended that due to siltation, utilization of water and useful storages in barrages will be reduced.
Answer: The proposed barrages are not like others, where sill levels of weirs are raised (like Prakasam and Cotton Barrages) to facilitate supply of water to canals. In such cases siltation will occur. The alternate barrages will have sill levels at bed levels and the regime of the river U/S and D/s is not disturned. The vent way would be equal 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.
Question No.3: It is contended that the Total storage in 4 barrages will be 53 TMC and only 33.5 TMC out of this can be utilized.
Answer: As explained in item2, the full storages in the U/s barrages upto the bed level namely 35 TMC can be utilized without any limitations of Minimum Draw Down Level (MDDL) with skillful selection of sites, approximate FRLs and Limiting submersions it is possible to get maximum storage at a place in between Bhadrachalam and Kunavaram and another on Shabari. Thus the total useful storage of 75TMC can be obtained only in 3 barrages. (33+23+19) (e.g. Storage at Kanthalapally=22.5TMC)
Question No.4: It is contended that cost of barrages would be Rs.9,000 crores.
Answer: 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 4000 crores. As a comparison the cost of Polavaram spillway and rock filled dam (2004-05 rates) was only 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 a fraction of this.
Question No.5: It is contended that as against 277 villages submersion in Polavaram dam, 128villages will get submerged under the barrages
Answer: According to the submersion area tables ofPolavaram Dam 30 villages will get submerged with FRL @ 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 1m interval contour map and the FRL s selected for the upstream barrages. The upstream barrages should have dykes in continuation of barrages such that the upstream floods may not submerge the Down Stream Areas.
Question No.6: It is contended that power production in the 4 barrages will be 271 MW
Answer: Power production contemplated at the Dummagudem barrage is 310MW. On the basis of this of this it is possible to produce about 960MW at the three barrages. However details have been worked out by GENCO. If there is any reduction, this will be only a disadvantage of the alternative proposals, and this has to be viewed against all other major advantages mentioned in my paper (especially eliminating dam break costing 46.15 lakh lives, limiting submergence of villages to 1/4th reduction of cost, early completion, navigation of sea going vessels etc.
Question No.7: It is contended that there will be 7.1 lakh acres under Polavaram dam and not 2.5 lakh acres.
Answer: WWF officials have made a realistic study of existing irrigated areas, Mandal 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 Perspectives of Polavaram). This is said to be due to apart irrigation under Tatipudi and Pushkaram L.I. Projects , Yelur project, Minor irrigation, GW (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 Government and WWF Officials. A much lesser storage than 75 TMC (As per the dam proposal) would be able to meet the requirements of the Ayacut. GW &LI 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.
Question No.8: It is contended that Orissa Government will oppose the alternative design.
Answer: 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.
Question No.9: It is contended that there is no navigation facilities for sea going vessels down stream of Dowlaiswaram and hence the same need not be provided on the upstream of Polavaram dam.
Answers: Two or three barrages will have to be constructed downstream of Dowlaiswaram upto the sea to facilitate the navigation of sea going vesseles. 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.
POLAVARAM DAM ALTERNATIVES : DOUBTS AND APPREHENSIONS
Question No.1 on Polavaram Ayacut : While AP state Government experts assert that Polavaram project irrigates an ayacut of 7.2 lakh acres independent engineering experts challenge the claim by stating that the project command area is already getting irrigated by other projects and hence Polavaram project provides irrigation to less than 2.5 lakh acres only. What is the correct position?
Answer: Andhra Pradesh Government proposals envisages an ayacut of 7.2 lakhs acres to be fed by the left and right main canals by gravity. Dr.Bhiksham gujja, Scientist, WWF and others, after a detailed study f the ayacut mandal-wise, determined that not more than 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, chapter9 “Perspectives on Polavaram”) These irrigation sources are:
o Pushkaram and Tadipudi Lift Irrigation (LI) projects which are having 2 lakhs acres under the gravity command of Polavaram canals (and 1.92 lakh acres outside the command).
o Yeleru project ayacut (Gravity flow) = 0.67 lakh acres
o Minor irrigation tanks, public (IDC) 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 and how they are not valid are discussed below.
The AP State Engineers are arguing on the various aspects of project as follows:
o “Pumpsets for lifting water from Godavari river to Pushkaram and Tadipudi 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 Godavari. These pump sets will be used elsewhere and the main canals of the LI projects will serve as part of the distribution system”.
o “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”.
o 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”.
o “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 is needed to examine the technical, financial and administrative aspects of the above issues. How far the above contentions are tenable and valid are discussed:
A) Pushkaram and Thatipudi LI Projects:
o The average static head of pumping from Godavari river is 18m and with frictional losses, the total head would work out to about 20m, when compared to the Devadula LI project (on the same river Godavari, now under construction), the static head is 275m (from Gangavaram river site to station Ghanapur) 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 Tadipudi LI projects will be about 5% of that of Devadula LI 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 LI projects, on the plea of power consumption would not be prudent for the following financial reasons:
o 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 LI 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.
o 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.
o The contention that the main canals of these two LI projects would be used as a part of the distribution system is not technically sound. The main canals of the two LI 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 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 LI 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.
o Lift for the two LI projects cannot be entirely avoided, even if their ayacut is tagged on to Polavaram canals. 1.92 lakhs 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 Godavari 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 Irigation (MI) Tanks: The ayacuts under minor irrigation (MI) tanks is included under Polavaram canals while calculating its ayacut as 7.2 lakh 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 AP 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 MI 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.
According to 2 reputed research papers published by experts of the Central Water Commission/National Water Development Agency and other experts. Out of about 1.4 lakh ha of cultivable area under Polavaram-Vijayawada link canal more than 70% amount to about one lakh ha was irrigated by borewells, tanks and openhead channels (GOI 1999)and according to another expert Bhaduri et.al.2007,95% of the cultivated area under this Polavaram Right Link is already irrigated as per details furnished under Appendix-IV of this paper. Similarly a large part of the land under the left link is also under irrigation sources like tanks, wells, borewells and canals and vast areas of lands proposed to be irrigated or proposed to be diverted for development of huge industrial complexes between Kakinada Port and Visakahapatnam Port. Thus the ayacut under Polavaram will get reduced to less than 1/5th i.e. from 7.2 lakh acres to less than 1.5 lakh acres.
For details see the following websites.
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.
Question No.2 on impacts on Godavari delta: If the proposed Polavaram dam is replaced by multiple barrages Godavari delta irrigation system will suffer due to water scarcity in Godavari river. Is it true?
A) No Water Scarcity due to alternate proposal: There are apprehensions (as seen in the print media reports) that Godavari 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 Godavari Delta will get more water than what is contemplated under the Polavaram dam proposal (now about to be constructed). This is more so when the same extent of live storage of 75 TMC would be made available in the proposed three barrages.
B) Possible dam collapse kills lakhs of people in the delta: The risk of dam break is not imaginary and when this occurs, the lives of 46.15 lakh people living in the Godavari 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 Godavari 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 Godavari 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 Godavari 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 45.72would 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 FRL.
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. Infact, all the earth dams will be constructed only with such convictions. But we see different results all over the world.
C) Actual cases of Dam collapses: The Earthen dams of two medium irrigation projects (namely Gundlavagu project and Palemvagu 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. 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 as far as possible, construction of earthen dams in the close vicinity of thickly populated areas. Polavaram earthen dam sits just upstream of an extremely thick populated area.
D) Water storage in the dam provides incremental floods: There is an argument that when a flood of 89 lakh cusecs occurs in the river, the areas on either side of the Godavari 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 natural occurrence of 89 lakh cusecs, this would occurs 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 happened suddenly in a few hours (unlike the dam burst wave)
E) Alternate Proposals ensures safety for people and their lands: This alternative proposal is suggested primarily in the interest of population residing in the Godavari delta, especially in the light of the recent occurrence f 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 Godavari 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).
Question No.3 on Navigation facilities: If the Polavaram dam is replaced by a barrage navigation will be adversely effected. Is it true?
Answer: 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.
Question No.4 on National Project status: If the proposed Polavaram dam project is modified Union Government will not take it up as a National Project. Is it true?
Answer: National Project status is for the project and not for the design. Such a status will facilitate 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 ½ 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 than 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.
Question No.5 on storage capacity: What are the impacts of the change of the dam with a storage of 75 TMC into a barrage?
Answer: 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 the author. For example, the author 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.
Question No.6 on costs of pumping: Will the annual costs of pumping change if the Polavaram dam is replaced by the barrages?
Answer: 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 the authors proposal detailed in his paper. Out of the hydropower generated in the low barrage of the alternative design (say 320MW), 54 MW 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 hydropower has to be costed notionally for comparison, (when the calculations are made based on the authors 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 KWH . 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.
Question No.7 on cost-benefit ratio: Does the cost benefit ratio gets improved if Polavaram dam is replaced by the barrage?
Answer: 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 workout to Rs.4000 crores. Assuming the R&R costs (to be worked out as per actual submersions), would be Rs.1500 crores (for the alternative proposal of much lesser submersion) and the cost of the canals and distribution system as Rs.3500 crores (some as in dam proposal) the irrigation component of that of the project (for the alternative proposals) would work out to Rs.9,000 crores. The total irrigation component for the “Dam” proposal would work out to Rs.18,700 crores (Rs.6700 crores for dam, spillway and power block-civil)+Rs,6500 crores (revised) for R+R+Rs.3500 crores for canal and Rs.2000 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.3,60,000/- per acre (Rs.9,000 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 2.07 times of that of the “Dam” proposal.
LOW BARRAGES –POWER GENERATION AND PUMPING COSTS
1. Barrage D/s of Bhadrachalam:
Q= 5,00,000 c/s or 14,158 cumecs on an average for peak power
H = 3.25 m – water level difference between U/s and D/s
MW = cumecs x Head/75 x eff x 0.746 = 14158 x 3.25/75×0.75×0.746= 343MW
2. Barrage across Sabari: Q = 1 lakh c/s or 2832 cumecs and H=10m (40-30)
MW = 2832 x 10/75 x 0.75 x 0.746 = 211 MW
3. Low Barrage at Polavaram Q = 5 lakh c/s or 14158 cumes & H = 4m (29-25)
MW = 14158 x 4/75 x 0.75 x 0.746 = 423 MW
4. Total Hydro power = 343 + 211 + 423 = 977 or 975 MW
5. Dia. Of Penstock pipes : 10nos turbines
Q = 50,000 c/s or 1416 cumecs (more number of penstocks & turbine units will have to be
Designed to suit discharge limiations)
For 8m dia pipes = A = 22/7 x 8sq/4 = 50.286 sq.m.
V = 1416/50.286 = 28m per second
6. Duration: All the turbines will work during flood days exceeding the above discharges On the other days, lesser numbers will work, depending upon discharges.
B) POWER CONSUMPTION FOR PUMPING FROM RIVER TO CANALS DATA
a) Total max discharge in canals = 11810 cusecs or 334.5 cumecs
b) Total had = 12.16m; HP = 71.360; KW = 53235 (54MW)
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.
e) The design of Polavaram main canals is not altered and they would still be capable of carrying the discharges required for Uttara Andhra Lift Projects and other lift projects on the Polavaram right anal. Cost of pumping and power charges for this would be part of those projects, since the same cannot be accounted under Polavaram project.
CALCULATION OF POWER CONSUMED
KW Hrs. consumed in 120 days or 2880 hrs.=54,000 x 2880 = 15,552 x10 (Power 4)
KW Hrs. consumed during the other days in the year (say about 30% of above )
= 4448 x 10 (Power 4)
= 20000 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 = 3x 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 costs borne by the Irrigation Department.
Posted by SHIVAJI RAO- ENVIRONMENTALIST at 5:56 AM