After the city's heaviest August rain in a century, two giant lakes in Bengaluru are spewing so much toxic foam that residents who live near them have reportedly complained that they are having to stay indoors. On Wednesday, the froth, a stinking cocktail of chemicals and untreated sewage dumped in the lakes, rose to over 10 feet in the Varthur Lake, spilling over a tall fence erected to keep the foam away from motorists on the city's Whitefield road. A day before the 1000-acre Bellandur Lake had hurled froth at motorists.