CHENNAI: Tamil Nadu government has sought environment clearance for building a flood carrier canal linking rivers Cauvery and Gundar to divert surplus waters to drought-prone districts. This was one of the projects which Chief Minister Edappadi K Palaniswami emphasised in the memorandum submitted to Union Home Minister Amit Shah during his recent visit to the city.
The State Environment Impact Assessment Authority has accepted the proposal on November 5 and Terms of Reference was issued on November 13 for carrying out environment impact assessment study. Under the project, water from the Cauvery that receives heavy flood due to rains in the Western Ghats will be diverted to the South Vellar and Agniyar rivers.
Senior officials in Public Works Department (PWD) told Express that it is proposed to divert 6,360 cusecs of water for nine days, from the availability of 8588 mcft from the surplus from Mettur dam at 50% dependability calculated for 83 years (1936 to 2018). Currently, a sizeable quantity of Cauvery water drains into the sea during good monsoon years like this year, which is such a waste of a precious natural resource.
“At the same time, the contiguous basins of Cauvery such as the South Vellar and Agniyar are facing water shortage for irrigation and drinking. There are only jungle streams originating from plains that also remain dry for the greatest portion of the year. Hence, it is proposed to divert the flood water from the Cauvery to deficit basins up to the Gundar for the benefit of people in Karur, Tiruchy, Pudukottai, Sivaganga and Ramanathapuram districts for sustaining drinking water needs and recharging groundwater,” said R Thiruvettaisellam, Superintending Engineer, Middle Cauvery Basin Circle, PWD.
In the first phase, it is proposed to build flood carrier canal up to South Vellar. Kulathur, Pudukottai and Thirumayam taluks of Pudukottai district; Krishnarayapuram and Kulithalai taluks of Karur district and Tiruverumbur and Srirangam taluks of Tiruchy will be benefiting from the project. Officials said the alignment of Cauvery (Kattalai) - South Vellar proposed link canal comprises six components.
A link canal of 256.82 km taking off from the Kattalai barrage with full supply level of 100.75 m and design capacity of 180.30 cubic metre per second (cumec). Tunnels of total length 9.25 km and branch canals and 25 direct sluices to facilitate irrigation en route will be built. The project would cost `7,677 crore and involves acquisition of 3,839 hectares of land. On a positive side, a total of 18,566 hectares would be irrigated through this project.
“Details of various welfare schemes for locals shall be outlined as a part of area development activities in the EIA report. A portion of 0.5 per cent of the project cost will be earmarked for local area development,” officials said. Tamil Nadu is one of the most water-starved States endowed only with 3 per cent of the nation’s water resources putting high stress on water availability. The average annual rainfall of the State is around 921 mm, which is less than the national average of 1,200 mm.
With distinct periods of rainfall and distribution pattern, Tamil Nadu is entirely dependent on monsoon rains for recharging its water resources and thereby, monsoon failures often lead to acute water scarcity and severe drought. As the State lies in the rain shadow region of the Western Ghats, it is deprived of rains during South West Monsoon, which is the assured monsoon for the rest of the country. Moreover, the spatial and temporal changes in rainfall distribution add woes to the cropping pattern in the State. Most districts in Tamil Nadu records deficit rainfall ranging from 19% to 59%.
Terms of Reference issued
State Environment Impact Assessment Authority has accepted the proposal on November 5 and Terms of Reference was issued on November 13 for carrying out environment impact assessment study