May 3, 2012. Mettur: Massive fish kills were reported within the confines of the barrages along the Chekkanur-Mettur stretch of the River Cauvery. The incident coincided with the annual cleaning and maintenance carried out by the Public Works Department, during which time stored water upstream of barrages is let out in batches, and replaced all along the belt from Erode to Mettur. Local residents say that fish kills occur during every maintenance schedule. According to them, chemical sediments released from upstream industries over a period of a year are stirred up during the flushing operations. These chemicals deplete the oxygen content in the water and killing fish en masse. Despite its regular occurrence, no steps have been taken to address fish kills during maintenance work, or to prevent the discharge of chemical effluents into the Kaveri.