2023 Delhi Flood Forecasting Error Due to Jamming of Yamuna River, Government Reports
The worst floods the city of Delhi ever faced when it was inundated completely along with several colonies. Flash flood-like situation left by the torrential rains stranded over 25,000 people living in the flooded areas. Taking suo motu cognizance of reports appearing in the media, NGT sought an explanation from the Union Ministry of Jal Shakti and Central Water Commission as to why the latter could not predict the flood precisely.
On 4 January, the Ministry of Jal Shakti and the Central Water Commission filed a report before the NGT stating the cause of failing flood forecasting that made the city face extreme conditions. The report said that severe congestion at Yamuna River between Wazirabad and Okhla barrages resulted in disturbances in the flow of water, which brought the accuracy of the flood prediction for the year down to 2023.
The flood prediction system relies for good predictions, on a free-flow river channel. Congested conditions owing to various reasons like ITO Barrage not opening all gates properly, formation of silt islands, debris, etc., floating along the river courses along with some ongoing construction activity-all these have paved the way for different segments of the river bed to block certain sections that might have created differences in conditions about water flows in the entire scenario.
These anomalies in the flow within the river caused distortions to the flood prediction at Delhi. In fact, according to this report, the surge in the water levels close to the site of the DRB was primarily because of an increase in discharge upstream of the Hathnikund Barrage. This led to a water level of 207.49 m, recorded above the highest documented flow on 12 July, 2023 at 1 pm, to a peak that occurred on July 13, 2023 at 6 pm at a level of 208.66 m.
The CWC stated that the altered flow conditions were so disruptive that they compromised the forecasting process that occurred because of congestion and obstruction due to the blockade of the course of the river in Delhi. Such irregularities could not have been accounted for in the forecast, based on the assumption of a free-flowing water channel. In this scenario, the CWC forecast did not predict the situation as it eventually came about, and therefore the city did not prepare itself for the severity of the flood.
These floods in Delhi, combined with forecasting problems, only left the administration with little time for mitigation measures and damage prevention. Again, the ministry led by the Ministry of Jal Shakti and CWC points out the requirement of better river management and flood forecasting in the future.
A committee comprising the chairperson of the CWC was formed to study the situation and advise corrective measures for the future flood forecasting. The flow of the river would have to be better managed so that all the gates of the ITO Barrage are opened, so that such a situation may not occur in the future. It also recommended coordination among those departments in the city of Delhi so that the problem regarding building up the silt bed, accumulation debris, and so on may reduce the obstruction inside the river for good prognosis.
Other recommendations by the report included that those constructions on the river side should be monitored closely and properly so that they do not disrupt the flow of water there. Frenzied development around the rivers has resulted in more construction and waste materials disposal, and the outcome has worsened conditions of some areas along the river.
This demands immediate ways of river management along with flood prediction systems. The heavy rainfall throughout the year 2023 has led to this flood. It was the failure of the predictive aspect that has multiplied the disaster effect. Strong infrastructure along with sound inter-agency coordination and advanced flood management tactics will play a significant role further in reducing the chance of flooding.
Conclusion:Now, centre government and the authorities of the Delhi municipality must get into this spree so that no such mishappenings are ever repeated in future. As these extreme events do increase with in number and intensity with climatic change, these cities too are to gear up themselves in mitigating the risk factors of flooding even better.Though much more is required to ensure that a calamity of this scale does not occur in the future again, the creation of a special committee and the report submitted by MoJS and CWC is a step in the right direction. Protecting the residents of Delhi from such flood disasters would be quite difficult in the near future without proper forecasting, free flow of water in Yamuna River, and removal of causes of congestion.
Source: Ministry of Jal Shakti, Central Water Commission, National Green Tribunal.