These two documents from the KSPCB website, provide monthly water quality status data, for the rivers Tungabhadra, Cauvery and Kabini, monitored between January to June 2007, at various points along the rivers.
The data recorded are Temperature, pH, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Faecal Coliform.
Download the documents: