On July 10, 2023, as Yamuna’s level in Delhi crossed “warning level”, like it happens during most monsoons, Delhi Chief Minister Arvind Kejriwal addressed a press conference. “Taking into account various predictions by experts, a substantial increase in the water levels of the Yamuna is unlikely,” the Chief Minister told reporters with a sense of relief.
But by 5 p.m. that day, the river breached the “danger mark” (a higher level, which puts different authorities on alert) and continued to rise to an all-time high on July 13.
As it turns out, it was not just the Chief Minister who got it wrong.
An analysis by The Hindu of forecasts issued by the Central Water Commission, the agency which monitors floods in India, shows that not only did it not predict that Delhi might see the worst flood in its history, but the agency, kept saying that the water level will “remain steady”, even as it continued to rise through July 12 to reach the highest ever level on July 13.
The forecasts of the CWC were being used officials of the Delhi government to take decisions and it affected decision making, multiple officers confirmed. “The only prediction of water level we have is from the CWC and if the prediction was better, it could have led to better decision making,” a senior official of the irrigation department of the Delhi government, which ran a flood control room in Delhi said.
Remain steady?
At 2:30 a.m. on July 12, as the water level of Yamuna kept rising, the CWC issued a forecast, that the level of Yamuna at the Old Railway Bridge (ORB) in Delhi, is expected to reach 207.1 metres between 11 a.m. to 1 p.m. July 12 and likely to “remain steady” thereafter. (The level at ORB is considered as Delhi’s official water level.)
But not only the river attained the level of 207.14 by 6 a.m., it kept rising after it.
This prompted the CWC to issue another forecast at 6:30 a.m., that the level is expected to be 207.35 metres between 11 a.m. and 1 p.m. on July 12 and likely to “remain steady” thereafter.
But by 10 am, the level was 207.34 and it kept rising after it.
The CWC, had issued a total of six such forecasts on July 12, all stating that the level would “remain steady”, but all of them proved to be wrong, official forecasts by the CWC, accessed by The Hindu show. These forecasts have not been put in the public domain by the CWC.
“We have been monitoring floods in India for over a decade and the CWC has gotten the prediction wrong on many occasions,” said Himanshu Thakkar, coordinator of South Asia Network on Dams, Rivers and People (SANDRP), who has been working on issues related to rivers for the past three decades.
Mr. Thakkar highlighted that lack of accurate predictions of water level of rivers have many times led to improper management of dams/barrages, leading to floods in downstream areas, which could have been avoided.
The CWC did not respond to an email seeking comments.
The CWC’s forecasts are output of a mathematical model created by the organisation and it is dependent on the rainfall predictions made by the India Meteorological Department (IMD) and other factors.
“The long-term forecast (five-day or seven-day) is dependent mainly on IMD predictions on rainfall and the short-term forecast (less than 24 hours) is chiefly based on water levels at different monitoring stations upstream from a particular point,” a CWC official said.
When asked about the mistakes in the forecasts, the official said, “The short-term forecasts also rely on cross section of the river and encroachments of floodplains could have reduced the width of the river, resulting in the errors.”
The official said that an interim report by a committee appointed by the Union Ministry of Jal Shakti (MoJS) has recommended that the ‘warning’ and ‘danger’ levels of Yamuna in Delhi should be reviewed. “The committee is also looking into possible issues related to forecasting of floods too in its final report,” the official added.
But the CWC has in the past claimed in official statements that they have predicted floods with an accuracy of 86-98%. When asked about this, Mr. Thakkar said, “These are just claims by the organisation and there is no third-party independent audit of it. The government should do audits, so that there will be transparency.”
This is last part of the five-part series Yamuna - Beyond Ebb and Flow. Click here to read the full series.
