Er S.K.Mohanty in Bhubaneswar, February 23, 2017 : For more than a century, engineers and planners in India have been contemplating on interlinking of rivers to divert surplus water from affluent basins to deficit ones for equitable water distribution. However, no one ventured to initiate any such move during British rule as well as during early stages in post independence period.

Dr K L Rao, an eminent engineer and former union minister mooted a proposal in 1972 to link river Ganga below Patna with the southern Kaveri river. Subsequently, one Capt Dastur proposed two garland canals, one for linking Himalayan rivers and the other for Central and Southern canals.

A few other proposals also came up in limited zones. The first serious attempt in this regard by government was the setting up of the National Water Development agency (NWDA) in 1982 to prepare the blueprint for this mega venture involving huge expenditures. This document was duly prepared, but no immediate actions were initiated till 2003 when the government of the day decided to give green signal to this mega scheme.

The Apex Court too gave directions to Union Government after hearing a public interest litigation (PIL) application to take up the works seriously and complete by 2016, but things did not move as desired. The Narendra Modi government has taken up this matter seriously hastening up activities all around along with fierce debate on the proposals.

However, green activists are united in opposing the move saying that it will be disastrous from both the environment and financial angles.

Need for Inter-linking of rivers (ILR)

‘Water’ is a precious gift of nature which is most essential for the living world besides air and food. Our mother planet ‘Earth’ has a huge volume of water, but only 3% of it is usable which come from surface run-offs in rivers and lakes and from underground sources. These are not evenly distributed around the globe resulting in water scarcity in many parts of the universe.

An assessment in 1995 indicated that 44% population of the world face water scarcity and this will rise over the years reaching the alarming levels of 57% in 2025 and 69% in 2075. The norm for scarcity is twofold. The first is the per-capita availability within a basin and the second is the ratio of water use and availability.

Many advanced nations face scarcity because of their excessive water use. In India, the norm followed is only the per-capita availability. If this is less than 1700 cum per year in a river basin, it is identified as a water scarce basin. Surface and ground waters in a river basin or locality depends largely on precipitation. In Himalayan terrain, precipitation comes from rainfall and melting of snow. In peninsular India, the precipitation comes only from rains and that too during the months from June – September. Some coastal areas get cyclonic rains in October as well.

Rainfalls are so erratic in India that the precipitation is very low in some states ,eg, Rajasthan, Gujarat, Maharastra, parts of Andhra, Telengana, Tamilnadu and Karnatak. Other states also face droughts in many years because of erratic monsoon mainly attributed to climate changes. NWDA have identified water scarce river basins in Sabarmati, Tapi, Mahi, rivers of Kutch, Krishna & Pennar in Andhra, Kaveri and southern rivers in Tamilnadu, Subernarekha, east flowing rivers south of Mahanadi and even Ganga. Water flow in Rajasthan desert is also negligible. One example of southern peninsula would highlight the matter.

In Krishna – Pennar – Kaveri river basins, the land area and population are 16 and 17% of the country, but the water availability here is only 6%. Per–capita availability in these basins are 1312, 648 and 666 cum respectively per year wihich make these basins water scarce. The per-capita availability in Sabarmati and west flowing Kutch rivers are as low as 421 and 631 cum only with Tapi and Mahi barely exceeding 1000 cum mark.

As a contrast, Brahmaputra, Narmada, Mahanadi, Brahmani and Godavari basins are water surplus. The Inter-linking of rivers aims at diverting the surplus water from the affluent basins to the needy basins on a national prospective. Instead of flood water flowing waste in to sea, it will 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.

Historical prospective at home and abroad.

Inter-basin transfer of water has been done earlier in several cases in many regions both in India and abroad. More than a century ago, water of the west flowing Periyar river in Kerala was diverted to east flowing Vaigai basin in Tamilnadu to generate power and then utilize the water for irrigation. Since independence, many more similar projects have come up. The most notable inter-basin transfer of water was done for Rajasthan canal (Indira Gandhi Nahar) project where waters of Sutlej-Beas in Indus basin is being diverted to the desert state across many basins.

Though not complete as yet, the Sutjej – Yamuna link is a classic example of inter basin transfer. The much hyped Telugu – Ganga project is diverting Krishna water to Chennai city which is located far away beyond the Krishna basin. Waters of Narmada are going across many basins to Kutch area in Gujarat’s Sardar Sarovar project. West flowing Koyna river is being diverted to the east in Maharastra. Krishna water is flowing in to Pennar basin through Kurnool – Cuddapa canal. In Tamilnadu, some of the west flowing rivers are dammed and water diverted to the Coimbatore area for providing irrigation in Parambikulam–Aliyar project.

In Odisha too, there are two such cases. Godavari water is being diverted to Mahanadi basin in Upper Indravati project. Water from Vamsadhara basin is coming to Rusikulya basin in Harbhangi project. In all these projects except Telugu Ganga, the concept was never to divert water from a surplus basin to a needy basin. The aim of the earlier executed works was to divert water to get some power and irrigation benefits in individual projects.

In most countries of the world, inter-basin transfer of water through linking of rivers are in progress in a big way. In China, Southern parts of China are water rich with two-third resources concentrated there. The northern China is more populous with 65% of the agricultural land and is water scarce. Works related to diversion of waters from Yangtze to Yellow river in North started in 2002 and it is partially complete now. The project’s estimated cost is 80 Billion USD and it will divert about 45 BCM of water (Billion Cubic metre or 109 Cum).

There will be about 3000 KM of canals of different capacities involving displacement of 3,30,000 people. 750 MCum of water is being diverted from Lesotho to South Africa’s Vaal River following a treaty between the two countries in 1986. The first phase was completed in 2004 at a cast of 2 Billion USD. In 2004 itself, Lesotho got revenue of 31 million USD which is 5% of their GDP. Four river basins are inter-connected in Spain to irrigate 1.76 lakh Ha and to provide water to 76 Municipalities.

The existing projects of USA will divert 45 BCM of water and they are planning another 376 BCM. Colorado river is diverted east ward ( 0.284 BCM) to Missori-Missicipi basin for utilization in 29 Municipalities and for providing irrigation to 2,51,000Ha. Water from the same Colorado River is reaching Arizona State via a Concrete aqueduct 541 KM long involving lifting at 13 places en-route and water is utilized in Municipalities and for irrigation at places located more than 1000m above the Colorado River.

In Canada, existing schemes when completed would divert 268 BCM of water. Many river linking projects are being done as well in our neighbouring country Pakisthan. India is in fact far behind in regard to inter-linking of rivers and the present government of the day is very serious to go ahead with some of the schemes. In this regard, the Apex Court of the country have given many directions to the Union Government to form special committees to monitor the schemes. Special committee has been formed now with 4 sub-committees and a Task Force to monitor the works.

Present Proposal

The government has mooted interconnection of 37 Himalayan and Peninsular rivers to create a water grid involving 30 links, 14 in the Himalayan region and 16 in the Peninsular region. When completed, there will be transfer of 33 BCM water in the Himalayan links and 141 BCM in the peninsular links. When completed, 35 Million Ha more will be brought under irrigation. Hydro installed capacity will also be increased by 34000 MW. There will be enough water for domestic, industrial and other utilities. 14900 KM of new canals will be dug and nearly 3000 more dams will be constructed.

When the cost estimates were prepared on pre- feasibility study, the overall cost was a staggering 11 Billion USD. It may be more now and much more when the schemes are actually completed. The objectivity of the schemes is to store the surplus water in storage reservoirs which would have flown waste to sea and then divert the same either individually or through relay process and also to provide en route utilization by way of domestic water supply, irrigation, industrial and environmental uses.

Himalayan concept has two sub–components. Surplus water of Brahmaputra will be first diverted to Mahanadi Basin via Subarnarekha and then to south. The second part is that all surplus water of eastern Ganga tributaries will be transferred to western tributaries and to Sabarmati basin. In this paper, it will not be possible to discuss about all the ILR proposals in India. The author wants to highlight only those projects which are related to the state of Odisha, either directly or indirectly in both the Himalayan and Peninsular components.

The main thrust in the Peninsular component is to connect Mahanadi – Godavari – Krishna – Pennar – Kaveri – Vaigai – Gunder, to carry water from surplus rivers to the deficit basins. Other links at Central India are Ken – Betwa, Parbati – Kalisingh – Chambal rivers. Some of the west flowing rivers are to be diverted to the east and all west flowing rivers south of Tapi and north of Mumbai will be connected.

Only 9 schemes are independent, but all the rest are dependent on each other. Government of India gave clearance to Ken – Betwa link in August 2015 and works have started. This scheme will also need a dam across Ken river (Daudhan) which is partly submerging Panna tiger reserve, but clearance has been given by the state wild life board in Sept 2015. 231 KM of link canal will be needed for this link. Present cost of the scheme is more than Rs 10,000 crore. It may even reach Rs 40,000 crore when completed.
Vital Link Projects to carry water to the south

NWDA have identified Brahmaputra, Mahanadi & Godavari as the surplus rivers. Two major tributaries of Brahmaputra originating from Bhutan are Manas and Sankosh. It is planned to construct mega storage reservoirs inside Bhutan for diversion of water to river Mahanadi via rivers Teesta, Mahananda, Ganga, Damodar and Subarnarekha. The entire quantum of water needs to be pumped at several places with giant pumps to reach Mahanadi River. Several barrages, canals, structures and regulators are needed to make the diversion happen in reality. It has not been assessed yet what sort of environmental, legal, administrative and financial problems will be faced in such long distance diversions.

Involvement of pumping at all these places makes the scheme very difficult if not impossible. Such diversions would need Bhutan’s approval and even Bangladesh’s concurrence which may be difficult. Problems in Mahanadi – Godavari (MG) diversions would be far less and not insurmountable. Surplus water of Mahanadi and residual flow, if any, from Brahmaputra will be diverted to river Godavari over a length of more than 800km and it will be a gravity flow.

The other and more important links are to originate from the river Godavari at Inchampalli in Telengana. A very large reservoir of surface area of more than 900 sq.km will impound enough water for diverting to the south. Huge quantum of water would be pumped from Inchampalli reservoir and carried over long distance conveyance in channels and tunnel (more than 300km each) in two different routes to reach Nagarjunasagar and Pulichintala reservoirs in AP and Telengana.

From these reservoirs water will be diverted to the south through gravity channels. If for some reasons, Inchampalli reservoir does not come up, the ILR programme to south would not be feasible. If there is no Inchampalli, there would be no need for Mahanadi – Godavari link and the ILR programme will be failing badly. However, NWDA would seek co-operation from all corners to make the Inchampalli reservoir, a reality. Even if Brahmaputra water does not reach Mahanadi, the ILR scheme would still be a successful scheme with somewhat reduced flow. States of Telengana, Maharastra and Chattisgarh should agree on all land acquisitions, rehabilitations and resettlement problems of large displaced persons.

……….to be concluded

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