Despite crores of rupees being spent on the Yamuna, pollution in the river has not decreased by significant levels, recent report prepared by Central Pollution Control Board has said. The Board has also warned that an increase in the supply of water to Delhi for the Sonia Vihar Plant is expected to increase the level of pollution in the river this year. The main pollutants, as in previous years, were the Capital's drains that bring in around 3,300 million litres of the total approximate figure of 3,600 million litres per day to the river.