Er S.K.Mohanty in Bhubaneswar, March 7, 2017 : The Inter-linking of rivers will go a long way in diverting the surplus water from the affluent basins to the needy basins from a national prospective. Instead of flood water flowing waste into sea, it needs to be diverted to needy areas without causing distress conditions inside the donor basins. The enormity of the scheme of interlinking of rivers is well understood, but the state has an obligation to perform when its citizens are in distress without adequate water in several parts of the country. It is in this context linking of two surplus rivers such as Mahanadi and Godavari becomes crucial.

MAHANADI–GODAVARI RIVER LINKAGE–PROBLEMS AND PROSPECTS

Mahanadi and Godavari (MG) are both surplus rivers according to National Water Development agency (NWDA). As per Krishna-Godavari Tribunal award, 80TMC (2265 Mcum) of water will be transferred from Godavari to Krishna from the Polavaram Dam (under construction) through the right canal up to Krishna through a gravity flow canal having a length of 174 Km. In view of this transfer, there will be no need for the Nagarjunasagar project to supply water to Prakasam barrage at Vijayawada for the existing delta irrigation in Krishna delta. This water will now go to the deficit basins of Pennar, Kaveri etc.

This right canal from Polavaram dam will carry 405 cumec flow at head and it will also have en-route irrigation of about 1,30,000 Ha besides stabilizing the existing irrigation system. Other en-route domestic and industrial supplies are also envisaged. There will be a similar Left canal with similar uses. Vizag city will get water from the left canal. For all these, Polavaram will have less water for the existing Dhawaleswaram delta irrigation. NWDA proposes to divert surplus water from Mahanadi to augment this. Hence, MG diversion is vital for NWDA.

NWDA proposed to construct a dam across Mahanadi at Manibhadra with a catchment area of 1,25,825 sq km to form a large reservoir having water surface area of 630.03 sq km at FRL and with  gross and live storages of 8520 and 6608 Mcum respectively. The proposed FRL was at El 91m and MDDL was 74.15m. Off-taking level of link canal at head was at El 74m. There will be some hydro power as well, the Installed capacity being 445MW. (Manibhadra dam 375MW) and canal PH (70MW).

The quantum of drawal would be 12,165 Mcum at head. After considering en-route utilization for irrigation, drinking water supplies in Odisha and Andhra and transmission losses, the flow would taper down to 6500Mcum at Dhabaleswaram, Godavari where the Pond level would be 13.64m. The 210 km long Manibhadra – Rusikulya link will carry 802 cumecs at head with a Bed Width of 73.50m and FSD of 7m. Beyond Rusikulya, the bed width reduces to 43m and the flow at head also reduces to 500 cumec. The bed width and quantum of flow further reduces after that up to Godavari.

In view of large submergence, Odisha did not agree and NWDA had to submit a revised proposal. As per this, the dam will come up at Bermul, 14km u/s of Manibhadra. FRL was reduced to El 80m from El 91m. FSL of link canal at head was kept at El 75m. Water diversion got reduced to 9182 Mcum from 12165 Mcum. Delivery at Dhawaleswaram was reduced to 4406 Mcum from 6500 Mcum. Five more new reservoir projects will be integrated with Bermul dam, which are Salki, Udanti, Roul, Bagh and Kharanga,    but NWDA have not furnished details. They have not prepared any detailed Project report for the revised proposal. Bermul submergence will come down to 137.68 sqkm, but the submergence of five new reservoirs will be 102.22 sqkm. Overall annual water balance of the scheme would be 11175 Mcum.

NWDA mentions that flood moderation will also be done, but it is not explained how and to what extent flood can be moderated. NWDA, CWPC and ministry officials made a power-point presentation about the scheme in the presence of Hon’ble CM, Odisha on 29.5.2015. Since then constant interactions are going on between NWDA and Odisha Government.

As the reservoir submersion is still very high, Odisha and NWDA have now agreed, on Odisha’s insistence, to construct a low barrage at Bermul only with FRL of 70m and Canal FSL of 55m. The submergence will be only 3406 Ha and only seven villages will be submerged. The link canal will have similar capacity carrying 802 cumec at the head.

A 200MW power station will come up at the canal head to utilize the head of 15m and the tail race water will flow through the link canal. According to NWDA, the water availability will be computed considering the five upstream projects. A lot more are to be studied regarding the integrated operation and the actual water availability. These details are not yet known and will be furnished by NWDA. Another alternative is also being studied with FRL of 74.15m.

CONSTITUTIONAL PROVISION AND LEGAL ISSUES

Water is a state subject under the constitution as per the Entry 17 – List II of the Seventh Schedule. For Inter-state Rivers, regulation is vested with the Union Government as per Entry 56 – List I of the Seventh Schedule. Article 262 of the Constitution deals with Interstate disputes. Parliament has already enacted law in this regard through an ‘Act’ in 1956 which is ‘Inter-state river water dispute Act, 1956’. Section 2 (c) of the Act defines ‘Water dispute’.

The Act contemplates the reference to a high powered ‘Tribunal’ by any State vide Sec 3 of the Act. Union Government would appoint a ‘Tribunal’ as per Sec 4(1) of the Act for the adjudication of disputes once they are convinced that there are no possibilities of any negotiated settlement between the States and their decision would be binding and even the Apex Court can’t interfere with the same.

Disputes relating to the rivers Krishna, Godavari, Narmada and Kaveri are already solved through Tribunal orders. Many others are still under adjudication including ‘Vamsadhara’. The position in regard to transfer of Inter-state rivers’ diversion to non co-basin states are not sufficiently clarified by the Krishna tribunal. Krishna – Godavari tribunal clarified that any riparian state of a river can divert its flow to another basin within the state.

Based on this, Odisha’s Upper Indravati project was approved. Based on this, Odisha has got the right to transfer Vamsadhara water inside the state and Harbhangi diversion is an example. The tribunal stated that they are not expressing any opinion on transfer to non – riparian states. Narmada Tribunal, however, stated that Rajasthan, a non – riparian state is not eligible to get Narmada water.

Most Inter – basin and Inter – State transfers of the past were done with mutual consent. The mega ‘Rajasthan Canal’ project diverting 9.362 BCM water would not have been possible if Punjab, Haryana and Himachal would have raised disputes. In case of  mega river – linking works, such ideal situations may not prevail. This will lead to river water disputes and formations of many tribunals. The works will be delayed indefinitely.

To ensure proper implementation of river – linking works, one view is to amend the constitution taking away the rights of the ‘States’, but this may never happen. It is the prime responsibility of the Union Government to influence and convince the states to solve all issues without raising disputes. It will be a herculean job for them.

RIVER LINKING – PROBLEMS GALORE

In India, many works were executed involving inter – basin transfer of water for beneficial uses, but these were mostly localized and were taken up with the consent of riparian states. Those projects with disputes are being adjudicated by various tribunals now. Inter–Linking of rivers involve inter–basin transfers, but all inter–linking of basins are not Inter–linking of rivers. The concept of transferring surplus water of a basin to needy basins is definitely a welcome move and this should be considered as a ‘Flagship’ programme of any Government irrespective of party politics.

Having accepted this principle, one cannot avoid building up of the storage reservoirs across the length and breadth of the country. We cannot avoid environmental and RR issues which are very sensitive. While doing so, the entire basin related local issues of the donor basins must be fulfilled first before diverting the water. The various Governments at the Center and States are to fight virtual wars for prolonged periods against environmentalists, opposition politicians, social groups and activists and the project affected people (PAP). The R/R policy should be drastically revised to see that PAPs are benefited substantially. This must be ensured somehow. India, as a country, must make a cautious beginning firmly, but surely.

In regard to its execution, the author’s views are different. The entire works should be spread over half a century or more and projects executed as per priorities. Ken – Betwa is already under execution in Central India. This involves a link canal length of 231 KM besides the dams and storage reservoirs. The estimated cost now is Rs 11,676 crores. It may reach Rs 40,000 crores when completed. One scheme which is ready now for execution and less problematic may be taken up in the Himalayan region.

As regards Southern peninsula, the Polavaram project works in AP are already in progress and the works of right canal is almost complete. All links connected with Polavaram are to be taken up together. As soon as the Polavaram dam is complete in about five to seven years time, Godavari water will flow to Krishna and hence Nagarjunasagar water will be available for diversion to Pennar instead of Krishna, which is being done now. As such, Krishna – Pennar link must be started soon. MG link should also start, but this will be a very long link and it may not be completed that early.

Till this link is ready to supply water to Dhawaleswaram, there must be restriction of use of water to the Polavaram left canal from the dam, otherwise delta irrigation will suffer. Some urgent works can also be started in the western front and these are not mentioned here. The progress of all the above mentioned schemes and problems thereof must be watched by the whole country and Government  for the next 15 years before starting other schemes. Staggering process will also help the Government exchequer.

The author has got grave reservations regarding the successful conveyance of water over such long water transfer schemes. Most coastal channels with a bed slope of 1:20,000 and carrying heavily silt laden flow will be silted up and there will be constant maintenance problems. During spells of drought, there will be danger of huge unauthorized drawal of water causing law and order problems.

If after spending so much money water does not reach the destination in desired volume, it will be an exercise in futility. This has happened in Telugu Ganga inter – basin water transfer scheme aiming at delivering 340 Mcum (12TMC) of water for the city of Chennai. The conveyance length is 433KM. The project started in 1983. Even though all works are completed and renovated, water supply has never exceeded 100Mcum. Authorities must take it as a test case to investigate why water is not reaching the destination. People of Kutch in Gujarat are also getting similar apprehensions if Narmada water will ever reach them. In all such long water transfer projects, there must be liberal provision of drinking water supply to all village/towns en route and irrigation.

Even though Government of India is sponsoring the river – linking works, there is every likelihood that there will be finance crunch if all works are simultaneously executed. The existing infrastructure of the country would not support such mega ventures running concurrently. Cost escalation of projects would put the Government in tight corner. One example would be enough to prove the point. Cost of Narmada scheme was Rs 6406 crores in 1986-87. It shot up to Rs 39240 crores in 2008 -09. By 2014, balance requirement was still Rs 8254 crores to create the balance potential of 12.46 lakh Ha. Most projects will have similar fate since the present estimates are based on feasibility study. The author apprehends serious financial bottlenecks if all works are concurrently taken up. The country has waited so long to make a beginning. Let the completion target extend over the next 50-60 years.

The Himalayan components need storage reservoirs in Nepal and Bhutan as well. It is doubtful if such possibilities can be taken for granted. Inter – linking of Himalayan Rivers may create sensitive issues with neighbouring countries of Bangladesh and Pakistan besides Nepal and Bhutan. Government of India should not lose sight of these important and sensitive issues. There must be friendly interactions in search of solutions.

Based on preliminary assessment the cost of ILR at 2002 price level was about 11 Billion USD. The completion cost 50 – 60 years hence may not be less than 100 billion USD, considering the usual escalations. The Government of the day must explain to the Indian people the source from where such huge money would come to take up this mega project. Any work which is started must be completed quickly to get benefit. Starting the entire scheme and lingering on with finance crunch will be harmful to the country. Even with all these handicaps, the present Government are seriously going ahead with this scheme and they are giving priority to MG linking.

MAHANADI – GODAVARI (MG) LINK CANAL – A CRITICAL ANALYSIS

Much before the ILR concept took shape, Odisha wanted to construct a second dam across Mahanadi to do away with floods in Mahanadi delta besides getting other benefits of power generation, irrigation and drinking water supply. The gigantic Tikerpada project was conceived and even foundation stone was laid in January 1964 by the then Prime Minister Jawaharlal Nehru, but could make headway due to strong opposition as the submergence was too huge to sustain. Odisha Government had no option but to drop the project.

After the disastrous floods of 1982, Manibhadra project was planned with much less submergence, but the R/R issue again became the stumbling block. The subject of constructing a 2nd dam across Mahanadi comes again and again for discussion after a major flood event in the delta area and its consequences and destructions, but it is forgotten again in view of wide spread protests against the dam.

There were at least four major flood events in the last 15 years when the dam issue came up for deliberation to be aborted each time. It is very doubtful if a dam would ever come up with enough flood storage to moderate the flood peak at Naraj. With this background, a dam proposal by NWDA across Mahanadi seems impossible.

Odisha Government would not agree for such a proposal even if Mahanadi delta is devastated by periodic floods in September when Hirakud reservoir does not contribute in flood moderation. The only option is to construct a low barrage with minimum submergence to divert the summer flow and get some power at head.

The author looks at the MG link from two angles. First is that Odisha state would contribute to the national perspective by diverting all excess water during the monsoon period to reach the Godavari delta for kharif irrigation there. The second angle will be in Odisha’s interest. Odisha will get the en-route benefit of irrigation, domestic water supply and industrial use, if any, besides enriching themselves with five new projects and added irrigation and other water uses.

Odisha will have to tolerate the submersions in these projects to get irrigation and other benefits. In author’s views, these storage reservoirs will not contribute to any flood moderations with their scanty storages. The author insists that NWDA should not take any water from the storage reservoirs during the non-monsoon period. As regards the diversion of flow, the principle to be decided is that the downstream requirement using Mahanadi water shall be met first throughout the year and any excess will be diverted to the link channel through the power house.

If there will be some excess flow during the non-monsoon period for whatever reasons, the same can also be diverted to the Link channel. This small quantum will be utilized en-route within the Odisha state for irrigation, if any, but mainly for domestic water supply to Brahmapur and other municipalities. This quantity will be too meager to be considered for long distance transmission.

PLANNING ASPECTS OF THE MG LINK – OUR VIEWS

Since flood flow of Mahanadi will only be diverted through the MG link canal and this quantum may not be sufficient to meet the need of Godavari delta, the author proposes to supplement it by combining the Mahanadi flow with the flood flow of other medium rivers en-route, eg Rusikulya, Vamsadhara, Nagavali, Eluru, Sharda etc to get the desired volume. On each of the medium rivers, Barrages will be built with the link canals joining the river upstream of the Barrages.

The 1st barrage will be constructed across Rusikulya and there will be a Head Regulator at the right flank from where the 2nd link starts. The link canal from Rusikulya will be designed to carry some quantum of Rusikulya flood flow plus the residual Mahanadi flow. This process will continue at each barrage site. These are presently not considered for diversion to Godavari by NWDA.

The MG link will only operate during monsoon and this flow will be utilized for the Kharif crop only. For the Rabi crop in Godavari delta, there must be allocated quantum from the Polavarm reservoir. All along the route, there will be en-route irrigation at feasible sites and domestic water supply. If Government of Odisha, NWDA and Ministry of WR accept this concept, they may take up further survey works to bring the project to feasibility stage.

In author’s opinion Odisha should accept the principle for diverting the surplus water going waste to sea in to the MG link only during the monsoon period. Odisha must compute their water requirement below the point of diversion considering long term uses. It is understood that this job has been entrusted to NIH, Roorkee. This quantum will be released downstream first from the low barrage. The balance will be diverted considering the pre-monsoon and post monsoon excesses. On paper, the scheme looks feasible, but detailed investigations will confirm it.

Odisha’s century old ‘Rusikulya Irrigation project’ will be benefitted greatly if the dry Rusikulya river is fed by Mahanadi both during the monsoon and non-monsoon seasons. Water shall be pumped from Rusikulya up to Madhabarida Anicut on ‘Bada Nadi’ and the link canal between Bada Nadi and Rusikulya would carry the flow by Gravity up to the Janivilli Anicut on Rusikulya river.  The entire ayacut of more than 60,000 Ha will be benefitted by this MG canal if Odisha Government takes up this ‘Mega lift’ project like many others which are under execution now.

CONCLUSION

Without the 2nd dam, the threat to Mahanadi delta will be always there and Odisha has to bear it periodically in future, but Odisha can still contribute to the national prospective by diverting the excess monsoon flow to the MG link by constructing a low Barrage  at Bermul or at any other place. If the authorities accept the concept as mentioned above, all en-route streams would also contribute to the MG link. As already stated, this link would only become operational during the monsoon period when every basin can contribute some flow which would be transferred to the Godavari basin. The MG link channel will flow by gravity and reach Godavari few Kms upstream of Dhawaleswaram Barrage.

In the opinion of the author, Odisha should immediately give their nod to NWDA so that the works of Bermul barrage and the Power House can go ahead at the earliest. If the Inchampalli reservoir does not come up resulting in the cancellation of MG link, the Bermul barrage can still be feasible with the Power House and a much smaller canal only to meet Odisha’s needs including Rusikulya system. What is required most at present is the political will power of the Government to think big to boost their agricultural out puts through reliable water received from river Mahanadi.

[The author is a retired Engineer-in-Chief of the Department of Water Resources (DOWR), Odisha]

• Part-1 of the article was carried in Bizodisha on February 23, 2017