In addition to rivers flowing in extreme flood situations at 64 flooding monitoring stations during Southwest Monsoon 2024, we have found that rivers have crossed highest flood level (HFL) at four stations during just concluded Northeast Monsoon season. Of these four stations, three are in Tamil Nadu state and one is in Union Territory of Puducherry.
One of these four flood monitoring stations Gandhavayal on Bhavani river is in Cauvery basin and the remaining three stations are part of East Flowing Rivers between Pennar and Kanyakumari basin. While the Bhavani river at Gandhavayal station has crossed the HFL after 11 years, the Ponnaiyar river at Vazhavachanur station has topped the old HFL by a margin of 3.32 meters.
Table showing details of flood monitoring stations where the rivers have crossed old HFL during the Northeast monsoon months.
| SN | Site/ River | District/ State | Old HFL (m)/ Date | New HFL (m) / Date | Rise/ Duration | Year after crossing HFL |
| Cauvery Basin | ||||||
| 1 | Gandhavayal/ Bhavani | Coimbatore/ Tamil Nadu | 95.15 m 24.11.2013 | 95.33 m 07:00 hour 23.10.2024 | 0.18 m ~05 hours | 11 years |
| East Flowing Rivers between Pennar and Kanyakumari | ||||||
| 2 | Vazhavachanur/ Ponnaiyar | Tiruvannamalai/ Tamil Nadu | 139.4 m 19.11.2021 | 142.72 m 05:00 hour 02.12.2021 | 3.32 m ~23 hours | 03 years |
| 3 | Venganur/ Periyaodai | Cuddalore/ Tamil Nadu | 78.79 m 10.10.2022 | 79.1 m 08:00 hour 13.12.2024 | 0.31 m ~06 hours | 02 years |
| 4 | Kumarpalayam/ Varahanadhi | Pudducherry | 15.255 m 19.11.2021 | 15.545 m 10:00 hour 02.12.2024 | 0.29 m ~09 hours | 03 years |
Rivers Flowing Close to HFL
The Sarabenga and Kallar rivers both in Cauvery basin have also narrowly missed breaching HFL during this period.
| SN | Site/ River | District/ State | HFL/ Date | Peak Level/ Date | Missed HFL by |
| 1 | Thevur/ Sarabenga | Salem/ Tamil Nadu | 173.2 m 10.02.2010 | 173.05 m 13:00 hour 04.12.2024 | 0.15 m |
| 2 | Odendurai/ Kallar | Coimbatore/ Tamil Nadu | 331 m 23.11.2023 02.12.2019 | 330.9 m 06:00 hour 04.12.2024 | 0.10 m |
Bhim Singh Rawat (bhim.sandrp@gmail.com)
SANDRP 