While trains bringing water to parched Chennai reiterates the gravity of the water scarcity, authorities say the ten million litres supplied by rail every day may only incrementally enhance supply to Chennai residents who are facing a forty percent cut in piped water supply. However officials say the state is using the lessons learnt to improve the ground water table. Assuring people that the minimum supply of water would be ensured till November, the focus from now on they say is going to be on revival of rain water harvesting and water conservation. NDTV spoke to Tamil Nadu's Water Secretary Harmander Singh.