In the first month of South West (SW) monsoon season June 2023, there have been Highest Flood Level (HFL) breach incidents at two sites. Both of these sites namely Suklai on Suklai river and DRF on Puthimari river are level monitoring sites located in Baksa district of Assam in Brahmaputra basin.
Interestingly, the old HFL at both sites were attained in 2020 and 2022 only and the old HFLs were breached thrice between June 15 and 20, 2023. The details of old and new HFLs for these sites are given in table below.
| SN | Site | River | Old HFL in meters | Date | New HFL | Date & Time | Rise above old HFL in Meters | Hours flowing above old HFL |
| 1 | Suklai | Suklai | 75.85 m | 25.06.2020 | 76.01 m | 15.06.2023 21:00 hr | 0.16 m | 16 hrs |
| 75.73 m | 25.09.2018 | 75.9 m | 20.06.2023 14:00 hr | 0.05 m | 01 hr | |||
| 76.18 m | 12.09.1983 | 76.05 m | 21.06.2023 11:00 hr | 0.20 m | 05 hrs | |||
| 2 | DRF | Puthimari | 144.51 m | 19.06.2022 | 144.54 m | 15.06.2023 20:00 hr | 0.03 m | 10 hrs |
| 144.43 m | 28.08.1988 | 144.79 m | 17:06.2023 07:00 hrs | 0.28 m | 23 hrs | |||
| 144.98 m | 20.06.2023 18:00 hr | 0.47 m | 103 hrs |
River Puthimari hydrograph for 17 to 28 June 2023.
Notably, the hydrograph inserted on Central Water Commission (CWC) flood forecast website the Puthimari river has not crossed the 144.45 meter level at DRF site between 17 to 19 June 2022. However, CWC has strangely mentioned the old HFL for the site as 144.51 meter dated 19.06.2022.
River Puthimari hydrograph dated 19.06.2022 showing water level not going beyond 144.45 metere.
Moreover, as per CWC old record, the DRF site was in Nailbari district with old HFL as 144.43 meter attained on 28.08.1988.
Similarly, the Suklai site was under Kamrup district with old HFL being 75.73 meter dated 25.09.2018 and 76.18 meter dated 12.09.1983.
River Suklai hydrograph for 17, 20 & 22 June 2023.
Given CWC old data as archived by SANDRP the HFL for the Suklai should be 76.18 meter dated 12.09.1983 and the CWC’s HFL for DRF site which is 144.51 meter dated 19.06.2022 is incorrect.
Other Issues in CWC flood monitoring in June 2023
Showing no sign of improvement, the CWC has continued its poor track record of maintaining HFL data and abruptly changing HFL information days after unusual increase in flood level in rivers. The two examples of the same has occurred in June 2023 as well.
Firstly, the hydrograph published by CWC flood forecast showed that the flood level in River Sipu at Bhakudar (Sipu dam) level monitoring site in Banaskantha district in Gujarat increased by 6.45 meter from 172.4 meter at 04:00 hour on 18.06.23 to 178.85 meter at 07:00 hour on 20.06.2023. During this period CWC mentioned no HFL data and date for the site. But on 21.06.2023, its website showed 186.48 meter as HFL (red line) for the site without revealing the date.
In second similar incident from Rajasthan, CWC hydrograph recorded flood level in River Banas at Swaroopgang level monitoring site in Sirohi district increased by 4.89 meter from 328.56 meter at 14:00 hour on 17.06.23 to 333.45 meter at 18:00 hour on 19.06.2023. However, CWC website revealed no HFL data, date for the site for two days and on 21.06.2023 inserted 333.54 meter as HFL for the site without any date.
In the third such incident, form Arunachal Pradesh, the CWC flood forecast website did not update the hydrograph for Lemeking level monitoring site on river Subansiri in Upper Subansiri district for more than 12 hours where flood level reached 1107.15 meter at 07:00 hour on 28.06.2023 which was just 0.01 meter short of its HFL 1107.16 meter attained on 27.07.2016.
Also, the CWC flood forecast website often keep flashing wrong HFL breach events. In recent such example, the website showed water level in River Tunga (Krishna basin) at Airani level monitoring site in Haveri district, Karnataka reaching 3714 meter at 18:00 hour on 26.06.2023 whereas the HFL for the site is shown as 527.03 meter dated 29.05.2023.
June 26, 2023 hydrograph wrongly showing unexpected increase in water level with incorrect HFL date.
Similarly, it displayed water level in river Narmada at Kaner at Mendhikheda level monitoring site in Khargone district, Madhya Pradesh rising upto 276.55 meter at 20:00 hour on 29.06.2023 which is 61.74 meter higher than the HFL 214.81 meter attained on 13.07.2022.
CWC has frequently been making these avoidable errors and abrupt changes in flood levels and HFL records during flood season without revealing sound basis and documents validating the reasons for the same.
SANDRP has raised these issues with CWC through twitter where the agency has replied to look into and correct the errors, however so far there is no correction made. The HFL for river Puthimari at DRF site is still mentioned as 144.51 meter dated 19.06.2022 while CWC on June 20, 2023 had replied that it will be corrected.
The HFL dates for Bhakudar (Sipu dam) and Swaroopgang sites on Banas river in Gujarat and Rajasthan respectively have not been inserted on CWC flood forecasting website as on July 06, 2023, though CWC had stated to update it in a message on June 21, 2023.
Regarding no updation of Lemeking site hydrograph for over 12 hours, Sharad Chandra, director, CWC said that the gauge was disturbed and the team was sent to rectify it. As on July 06, 2023 the hydrograph for the site is still running late by 12 hours.
Bhim Singh Rawat (bhim.sandrp@gmail.com)
SANDRP 