Kerala Floods : Extreme Rainfall Major Cause; Need Expert Body To Enquire Role Of Dams, Reports Amicus Curiae To HC [Read Report]

Extremely heavy rainfall which was not anticipated was the major cause of floods in Kerala last year, said the report filed by amicus curiae appointed by the High Court of Kerala. Kerala received 42% more than the normal rain fall between June  to August 2018 and the rain fall between August 15 to 17 was extremely heavy and torrential in nature, mentioned the report.

The amicus also opined that various other factors such as high storage levels in dams in the first week of August 2018 coupled with sudden discharge from dams during August 15-17, absence of proper flood forecasting system, reduced storage capacity of dams due to siltation etc, may have aggravated the flood situation. It was highlighted that all 79 dams in state were maintained with the objective of hydel power generation or irrigation and none of them had flood control as a purpose. The amicus expressed that detailed study was needed to examine whether these factors worsened the flood situation and suggested the constitution of an independent expert body headed by a retired judge and consisting of renowned experts in the field of hydrology, dam management etc. for that purpose.

The 49-pages report was filed by Advocate Jacob P Alex, who was appointed amicus curiae by the High Court to give assistance in deciding a batch of petitions which alleged that floods were a man-made disaster caused by sudden release of water from reservoirs without proper precautionary measures.

The Kerala Government has taken the stand that extreme rainfall between August 15- 17, which was not predicted in the forecast by Indian Meteorological Department(IMD), was the sole cause for floods. By stating that the live storage capacity of dams were only 7.4% of the annual average run of rivers, the Government denied any role of dams in floods. No early release of water was possible as there was no IMD forecast about high intensity rainfall between August 15-17. Since most dams were near full reservoir level by second week of August, they had to be suddenly released to accommodate the unanticipated spike in inflow during August 15-17, said the Government.

The Central Government said that flood situation was not due to heavy rainfall on any particular day and was due to accumulated effect of persistent heavy rain fall over the monsoon season. It said that IMD can only give a general forecast about high intensity monsoon, and cannot accurately quantify the exact amount of rainfall on a particular day at a specific location.

Reports of Central Water Commission(CWC) and other experts.

The amicus referred to the reports prepared by the CWC and experts from the IITs on the role of dams in floods. These reports ruled out any role of dams in causing floods.

"Dams in Kerala neither added to the flood nor helped in reduction of floods, as most of the dams were already at FRL(Full Reservoir Level) or very close to FRL on 14.08.2018 due to more than normal rainfall in the month of June to July 2018. In any case it would have been necessary to release water from reservoirs after the first day of extreme rainfall", the CWC had opined.

The amicus also referred to another report by Himanshu Kakkar published in Economic and Political Weekly, disagreeing with the CWC findings by saying that CWC did not examine whether dam operators did everything possible to moderate floods in the downstream area.

The report termed the CWC findings as a "rapid assessment report" which omitted to take into account the National Water Policy, National Disaster Management Authority's guidelines etc., and stressed the need for a "detailed enquiry" to identify the causes of floods

Extreme Rainfall main reason

Based on the materials on the record, the amicus observed :

"It is seen that Kerala received above normal rain between 01.06.2018 and 19.08.2018. It was above 42% of the normal rainfall and that the rainfall between August 15 and 17 was extremely heavy/torrential in nature. This is the main reason for the deluge".

The report added that "most of the major reservoirs were almost full before the extreme rainfall occured on August 14-16" and that the "authorities were compelled to release substantial amount of water from reservoirs in a short span of time, at the peak of rainfall period".

Other factors

At the same time, the report observed that the dam management in Kerala was not in accordance with the National Water Policy and Guidelines of National Disaster Management Authority on flood control.

The major concern of the dam operators was to maximise reservoir levels, which conflicted with the flood control purpose for which the dams could be utilized.

The 'flood cushion' of reservoirs - the storage space earmarked in dams to absorb unanticipated high flows-  needed review as per the latest guidelines, said the report.

"It appears that dams in Kerala had not maintained effective flood control zone and the flood cushion said to have maintained is not as mandated by the BIS Report, RTIOR(Real Time Integrated Operation of Reservoirs) and O&M Manual"

While the report agreed with the Government's version that exact IMD forecast on high intensity rainfall was not available, it found fault with the dam operators for only relying on IMD. The dam operators ought to  have relied on "hydrologic forecasting", opined the amicus.

"dam managers ought not to have solely relied on IMD predictions and variation in IMD prediction or forecast cannot be counted as a justification for delayed release of water from dams"

Other preliminary observations made in the report are :

• Emergency Action Plan(EAP) for dams has not been formulated in the State.
• Warning alerts (Blue/Orange/Red) were not issued as per EAP guidelines.
• No proper follow-up action or precautionary steps (especially for evacuating people and accomodating people in safe locations) were taken after issuance of Red Alert
• Reduced storage capacity in dams due to siltation.
• Rule Curves of dams - the target level planned for dams under different probabilities of inflows at different periods in a year- were not updated.
• No Real Time Integrated Operation of reservoirs to enable quick response.

The amicus also suggested that decision regarding release of water should be taken by specialized agencies like Dam Safety Authority or Disaster Management Authority.

On the basis of these observations, the amicus recommended a detailed enquiry by an independent body headed by a former judge of superior court and preferably consisting of experts from the fields of hydrology, dam management, engineering etc to identify causes that worsened flood situation and to make suggestions for strengthening the dam/flood management aspects in future.

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