Blame it on Hirakud? Flood management issues in River Mahanadi, India
By Ranjan Panda
The CAG has rapped the Odisha government for not keeping the dam's water level in check and failing to prevent flooding in downstream areas.
Man-made floods due to release of huge quantity of water from Hirakud dam have come back to haunt Odisha. The Comptroller and Auditor General of India (CAG), in its recent audit of the ‘schemes for flood control and flood forecasting’, has rapped the Odisha government for not keeping water level in check and failing to prevent flooding in downstream areas. When we had raised the issue before the government in 2011, it refused to consider our recommendations.
The CAG found out in its audit that non-maintenance of water level in Hirakud dam as per the Rule Curve and simultaneous opening of many gates caused heavy discharge of water resulting in flooding in downstream areas. The CAG has given examples from both 2011 and 2014 floods. In fact, what the CAG could not report—or perhaps was not given information about—is the fact that ‘water to industries’, which has been added to the Dam’s list of water allocation priorities, can be considered as the main reason for this mismanagement. Moreover, the dam’s original design, though aimed at flood control, has failed to factor in real flood control measures. The reservoir does not have a specific 'flood cushioning limit' earmarked.
The Odisha Water Policy, as the CAG points out, mentions that flood control would be given overriding consideration in the reservoir regulation policy even at the cost of sacrificing some irrigation or power benefits. This is perhaps because the officials of the state have given the CAG an impression that they have violated the Rule Curve by maintaining the water level of the reservoir at a much higher level against the prescribed limit to meet irrigation and power needs. But the reality is something different, as we have been observing in the ground. The commitment to supply water 24X7 to industries for 365 days was added as a priority in the early 90s—almost four decades after the dam was built. However, it actually goes against the very design of the dam. The lack of long-term accurate weather forecasting forces the dam operators to assume the volume of future rainfall. As a result, they have developed this practice of violating the Rule Curve to be able to keep sufficient water in the reservoir.
As per the existing Rule Curve, the minimum water level of the reservoir should be 595 ft by July 1, 590 ft by August 1, 605-615 ft by August 11, 610-622 ft by August 21, 619-627 ft by September 1, 624-629 ft by September 11, 629.5-630 ft by September 21 and 630 ft by October 1. But the authorities–year after year—are keeping the water level almost more than 15 ft higher than this limit and then finding it difficult to release the water instantly when there is heavy rainfall upstream. That caused the floods downstream in 2011 and 2014.
Now that Odisha is engaged in an inter-state river water dispute with Chhattisgarh over Mahanadi River, this CAG report must be taken into serious note. In our several letters to the Odisha government in the wake of 2008, 2011 and 2014 floods, we urged the government to change the Rule Curve that was framed in 1988 by a high-level expert committee. This Rule Curve has been outsmarted by the change in rainfall patterns due to climate change and more recently, due to the building of number of dams and barrages upstream by Chhattisgarh.
We have, for over a decade, been asking both Odisha and Chhattisgarh governments to improve the flood forecasting and management methods as well as coordination. However, the governments not only have been on a refusal mode but also have not found any pressing reason to work out a new Rule Curve that would factor in latest problems and technologies.
The CAG audit report was presented in the Parliament on July 21, but the Chief Engineer of the Hirakud Dam seemed to have no information about it on July 23 when he was interviewed by media persons on the problems with regard to the Rule Curve. Thus, he said, ‘all is well with the system.’ On June 28 this year, while the Chief Minister of Odisha was launching the real-time flood forecasting model for the Mahanadi basin, he said that it would help getting flood-related information from Chhattisgarh 72 hours in advance. Ironically, on the same day, water department officials alleged that Chhattisgarh was not sharing information of floodwater discharge from its dams.
Hirakud, an ageing dam, has been facing several other challenges, including its safety. Resorting to an old Rule Curve and lack of coordination between the two states would make things further worse. The dam is already causing more flood-affected areas than it was supposed to prevent. Any further complacency will not only make the dam more ineffective but also aggravate the problem of flooding as well as inter-state conflict.
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