Troubled waters: sewage and effluents sink the Cauvery

Key Points

1. Cauvery River receives water from multiple tributaries, many functioning as drains.
2. Mettur Dam regulates Cauvery's flow; towns and industries draw water for various uses.
3. A fraction of sewage across the Cauvery basin is adequately treated.
4. Industrial effluents are allegedly discharged into the river when surplus water is released from Mettur Dam.
5. Erode has a 17-kilometre stretch within the Erode Corporation limits that is highly contaminated.
6. Erode generates 35 to 40 million litres of sewage daily, but only about 8 MLD is treated.
7. Dyeing units relocated to Cauvery banks after facing closure in Tiruppur.
8. Zero liquid discharge systems were adopted in Karur due to protests and court rulings.