The Calcutta Municipal Corporation (CMC) has drawn up a plan to bring 85 per cent of the city's population within the filtered surface water network by 2009. It is investing over Rs 200 crore for the project. At present, 62 per cent of the population is supplied with filtered surface water. The previous Trinamul Congress-BJP civic board had invested a whopping Rs 390 crore to "provide a major boost' to the water supply infrastructure. But the efforts failed to expand the network, with only 35 of the 300 deep tubewells having been sealed.