Tamil Nadu begins inter linking of Rivers

While the task force of the national river linking project is still deliberating, Tamil Nadu, a water deficit state dependent on its neighbours, has taken a significant step forward to link rivers within the state.The DMK government passed an order recently sanctioning funds for building a barrage across the Cauvery river to take flood waters to the Vaigai river through drought-prone districts and irrigate an additional 3.37 lakh hectares of cultivable land. Simultaneously, a project to link Tamirabarani and Nambiar rivers down south will also be launched soon.The new barrage will be constructed 250 metres downstream from the Kattalai bed regulator that was constructed in 1934 at Mayanur village in Karur district. The chief engineer of the water resources department of the PWD had written to the government stating that the bed regulator was not effective in distributing water through the four channels downstream. The proposal for the 1.3-km barrage, envisaged by the National Water Development Agency (NWDA), had been in the pipeline for a while. The barrage is an integral component for the southern river grid to become a reality. The barrage would improve irrigation and streamline distribution into the four channels. During monsoon, it could help storage of 1.4 tmc and during floods, 5.4 tmc could be diverted through proposed gravity and contour canals to drought-prone areas by linking Agniyaru, South Vellaru, Manimutharu, Vaigai and Gundaru. Understanding the enormous benefits of the barrage, the state through a government order (No 116 of PWD) has sanctioned Rs 50 crore for taking up works in 2008-09. During the budget session of the Assembly this year, the state finance minister K Anbazhagan announced that the state would take up the Tamirabarani-Karumeniar-Gundar link project and construction of Kattalai barrage across Cauvery at a cost of Rs 369 crore and Rs 165 crore respectively. As the detailed project report (DPR) for the Tamirabarani–Gundar project and the first phase of Cauvery–Vaigai–Gundar have already been completed, the chief minister sanctioned Rs 100 crore directing the public works department to start work immediately. “Usually, flood water flows over the existing bed regulator and damages infrastructure along Coleroon and drains into the Bay of Bengal. The barrage, as per the design, will mitigate the effect of floods and carry the waters to drought prone areas through a canal for 255 km and later link up with rivers in the southern districts,” saidan official. According to the National Water Development Agency’s national perspective plan (NPP), the link canal could provide en route irrigation to 3.37 lakh hectares of cultivable land, utilising 1952.30 Mm3 (roughly 5.4 tmc) of water besides providing 185 Mm3 for meeting domestic and industrial requirements. As per NPP, the link project could be completed in six years at a cost of Rs 2,673 crore (2003-04 price level). The net annual benefits from irrigation are worked out to be Rs 772 crore and through water supply Rs 168 crore.
The Cauvery (Kattalai) – Vaigai-Gundar link canal is proposed as a contour canal running for a total length of 255.60 km till it joins with Gundar river. The link canal is aligned through Krishnarayapurm, Kulithalai taluks of Karur district; Srirangam and Tiruchchirappalli taluks of Tiruchchirappalli district; Kulathur, Pudukkottai, Gandarvakkottai, Alangudi, Arantangi, Thirumayam and Avudayarkoil talukas of Pudukkottai district; Karaikudi, Devakottai, Ilaiyankudi, Tirupattur, Sivaganga and Manamadurai talukas of Sivaganga district; Tiruvadanai, Paramakudi, Kamudi, Ramanathapuram, Kadaladi and Mudukulathur taluks of Ramanathapuram district; Tiruchuli, Kariyapatti and Aruppukkottai talukas of Virudhunagar district.
Tamil Nadu has also launched a project to link the Tamirabarani and Nambiar rivers down south. The Rs. 369-crore project will be undertaken along with the Cauvery project which hopes to feed the drought-prone districts in the state.As the Tamirabarani river basin is surplus, the state has proposed to take water from the upper reaches of the river to Karumeniaru and Nambiaru river basins, both water deficit.Fed by 11 tributaries and nine reservoirs, Tamirabarani, flowing for 126 km, has a surplus of 13,000 mcft after irrigating 80,000 hectares and meeting domestic and irrigation requirements. The present plan is to divert 2,750 mcft of water to fill 252 tanks and irrigate 20,040 hectares. As per the plan, the water will be diverted at the 3rd anaicut at the confluence of Manimutharu and Papanasam river through the existing Kannadian channel that runs for 37 km. At another barrage at 6.4 km, the water will be further diverted through a new channel, to be created, for a length of 73 km till the village in Thisayanvilai named `Emmal Theri,’ right at the edge of the coast. Irrigation in the intervening areas will be improved through construction of a network of smaller channels. The government hopes to complete the project in three years. A key component of the scheme is increasing the carrying capacity of existing Kannadian channel from 450 cubic feet per second to 3680 cusecs by widening, lining and strengthening the banks up to 6.50 kms. It would also involve improvement works on the Kannadian anaicut to increase its efficiency. The areas that would be benefited by the scheme are five villages in Palayamkottai taluk, 17 villages in Nanguneri taluk, 10 villages in Radhapuram taluk, 16 villages in Sathankulam taluk and two villages in Tiruchendur taluk. By implementing the scheme, an ayacut area of 6,038 hectares stand to benefit, besides another extent of 17,002 hectares would have their ground water table recharged, thereby taking the total extent of anticipated benefit to 23,040 hectares. The land required for implementing the scheme is a total area of 800 hectares, of which 694 hecatres would be in Tirunelveli district and 106 hectares in Tuticorin district. The land to be acquired consist of dry lands, wet lands and poromboke lands. The project proponents have also computed the benefit-cost ratio for the project at 2.26:1. In terms of additional food production, they anticipate 1.82 lakh tonnes of paddy.