Kochi: The report submitted by the amicus curiae appointed by the high court on Kerala floods is not having any clear answer to the findings of the Central Water Commission, and the IIT Chennai reports on the disaster.
Instead of considering the detailed sub-basin level data on the storage capacity of reservoirs and the velocity of inflow and outflow of water from dams the amicus curiae report has done a cut-and-paste job of compiling a series of recommendations and suggestions made by various government agencies over the years on flood management and its non-implementation as the main reason for aggravating the situation.
The amicus curiae report states that "None of the 79 dams in Kerala was operated or used for the purpose of flood control/moderation despite the obligation to utilize the dams for the purpose of flood control/moderation also as per the National Water Policy, NDMA Guidelines on Floods".
The report, however, mentioned it to say that none of the dams in Kerala was designed for flood control and the matter calls for policy correction on a long-term basis.
The report also failed to mention that the total live storage capacity of the 57 large dams in the state is 5.806 BCM comprising just 7.4 per cent of the annual average runoff all 44 rivers in Kerala which is about 78 BCM as stated in the report of the CWC.
The CWC report has also mentioned that out of the 57 large reservoirs only seven are having a live storage capacity of more than 0.20 BCM and they constitute 74 per cent of the total live storage in Kerala.
The detailed data-based comparative analysis done by CWC on the runoff volume generated and the discharge records in the Periyar, Pamba, Chalakudi, Bharathapuzha and Kabini sub-basin areas during the August 15-17 rainfall failed to find any mention in the report.
The CWC analysis on the Periyar sub-basin with nearly 50 per cent of the total live storage of the state comprising 2.92 BCM during the period shows no justification for the theory of sudden release of water from dams causing floods. Periyar sub-basin comprised of Idukki, Mullaperiyar and Idamalayar reservoirs.
According to the CWC report, the water level in the Idukki dam crossed the full reservoir level (FRL) of 732 m on August 10 leading to increasing the spill from the reservoir.
The process helped to bring down the water level to 730.80 m by August 13 providing an extra flood cushion below FRL to about 90 MCM. The heavy rainfall on August 15-17 took place in this background which led to the inflow the dam very much forcing the authorities to open the dam gates.
The average release from Idukki reservoir on 15-17 was 1,100 cumecs, 1,400 cumecs and 1460 cumec as against the inflow of 1,640 cumecs, 2000 cumec and 1,440 cumec. According to CWC the flood peak recorded at its gauge station at Neeleswaram was to the tune of 8,800 cumecs.
"Even if there were no or very little release from Idukki reservoir (a hypothetical situation in the wake of floods of such magnitude), the downstream areas would still have received a peak of about 7500-8000 cumec. Therefore, it can be concluded that the Idukki reservoir's contribution to the overall flooding situation downstream was minuscule.
It had provided an attenuation of flood peak by about 1,030cumec when peak inflow impinged the reservoir", said the CWC report.
The report has also reached a similar conclusion on the other sub-basins like Pamba, Chalakudi, Bharathapuzha and Kabini, debunking the theory that dam openings worsened the flood and made it a man-made disaster.
