Tamil Nadu has been hit again by the ‘June 12 syndrome’.

It is not just about the poor storage in the Mettur dam, which has delayed the scheduled water release for irrigation in the Cauvery delta this year, or concerns at the formation of the Cauvery Management Board to oversee the implementation of the Tribunal’s final award.

The development debate in the Cauvery delta districts faces another challenge in a project proposed to extract methane from lignite seams over 667 sq km, after the previous UPA government at the Centre gave the approval for a ‘Coal Bed Methane (CBM)’ pilot project to be executed in the ‘Mannargudi block’ by a Gurgaon company.

This has triggered more worries among the farmers in Tamil Nadu’s ‘rice bowl,’ which accounts for 25 per cent of the State’s annual rice production. They fear the project will lead to a huge groundwater depletion, “aggravating” their livelihood uncertainties stemming from the non-release of water from the Mettur dam as per schedule. Though Chief Minister Jayalalithaa in July 2013 constituted a committee of experts to study the project’s impact and urged the Centre to suspend it until the committee came out with its findings, farmers are in an “agitating mood.” They want the project stopped, says P.M. Natarajan, a veteran hydrologist and water resources expert.

Dr. Natarajan, who had participated in the famous hydrological investigations of the Cauvery delta conducted by the United Nations Development Programme (UNDP) in the 1970s — their findings were a crucial input for the Justice Chittatosh Mukherjee-led Cauvery Tribunal — said the proposed methane gas extraction from the lignite seams “will affect the water resources, and hence foodgrains production and the livelihood security” of farmers.

Sharing his research insights with The Hindu, he said the total groundwater “in the main flowing zone of the Cauvery delta located in the coal bed area is only 4.77 tmc ft (thousand million cubic feet), as per the UNDP. The project, he said, would involve withdrawal of about 2.03 tmc ft of groundwater a year. It might have to be pumped out as in Neyveli Lignite Corporation areas. So, if a ‘production phase’ of 25 years was allowed for the company, 50.63 tmc ft was likely to be tapped. This would mean “the entire groundwater in the flowing zone [of the delta] and in the shallow aquifers would be pumped out in five years or sooner,” Dr. Natarajan argued. To compensate for such a huge “drawdown,” there would be a groundwater flow from the coastal side, leading to “seawater intrusion and salinisation.”

Arguing against the project, which he said “is likely to create hydro-geological, socio-economic and environmental disturbances to the delta which is already facing water scarcity,” he feared it would only lead to more “migration of farmers as water refugees.”

At a workshop held at Thanjavur last year, the representative of the company (Great Eastern Energy Corporation Limited) sought to dispel farmers’ apprehensions by arguing that the latest precision technology would be used to extract gas “from the crevices of the lignite belt” to prevent any “collateral damage” to either the groundwater aquifers or to the surface. But this had no takers among the farmers.

Veteran leader of the Cauvery delta farmers S. Ranganathan, himself a geologist-turned-farmer, pointed out even then that the Centre should reconsider the project as the delta districts of Thanjavur, Tiruvarur and Nagapattinam, which had an ancient irrigation system dating back to the 2 century AD, would be adversely hit. A ray of hope that has come recently for the farmers has been the Tamil Nadu Congress Committee reversing its stand in favour of the project.

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