Despite it being a dry month, the stock in lakes supplying water to Mumbai increased at least by 9 per cent during the past three weeks. BMC officials attribute it to percolation and intermittent rain in catchment areas. 

The lakes had 74 per cent water stock on July 31, and on August 20, the stock increased to 83.50 per cent. “It is due to the percolation effect as well as due to scanty rain of 10 to 15 mm intermittently in the lakes,” said Purushottam Malavade, chief of hydraulic engineering department of the BMC. Percolation means water runs downwards through the tiny gaps between rocks and soil particles, subsequently saturating the underlying rock. This helps to replenish water bodies.