HYDERABAD: The latest report by the National Dam Safety Authority (NDSA) has found that the sinking of the piers (foundation) of Medigadda barrage is due to a combination of issues involving failure in planning, design, quality control and operation and maintenance.
After six piers of the Medigadda barrage were damaged recently, the NDSA visited the spot and held a meeting with Irrigation officials before submitting its report.
The report, which came out today exposed several shortcomings in the commissioning of the Medigadda barrage, which is an integral part of the State government's prestigious Kaleshwaram Lift Irrigation Scheme (KLIS).
Immediately after the report was out, Jal Shakti Minister Gajendra Singh Shekhawat tweeted: "Exposed! K Chandrashekar Rao led Telangana govt’s corruption stands hopelessly exposed. It is appalling to know that the greed & corruption of the BRS govt has led to risking the lives of lakhs of people & loss of crores of rupees of taxpayers’ money".
However, the State government officials are yet to react to the report of the NDSA.
Recently, the irrigation officials announced that the sinking of piers was due to the washing away of sand beneath the pillars of the Medigadda barrage.
The NSDA, in its report, mentions that the reasons for the sinking are due to transportation of the foundation material (sand) below the barrage foundation, inadequate bearing capacity of foundation material, failure of upstream secant piles due to barrage load etc. This indicates failure in planning and designing of the barrage.
"These are deficiencies in the project planning & design. The Barrage has been designed as a floating structure but constructed as a rigid structure. The contiguous secant pile type cutoffs adopted by the project authorities were taken up to rock both upstream and downstream of the barrage. This has changed the structure behaviour from the designed," the NDSA report said
NDSA has regularly asked the Telangana State Dam Safety Organisation to get done the pre and post-monsoon inspections to check for any unusual behaviour or signs of distress. But, it appears that this has not been complied with.
The damaged block no.7 has to be structurally restored (cannot be repaired and has to be removed and reconstructed from the foundation) to make it functional. Considering the commonalities, the likelihood of the failure of other blocks resulting in a similar mode exists. This would warrant rehabilitating (reconstructing) the whole barrage, the report said.
Not to store water: The filling of the reservoir in the present condition would worsen the barrage's health and should not be resorted to. That is the barrage under the present condition cannot be functional until rehabilitation (reconstruction). The NDSA also suggested various precautionary measures to be taken.
Two barrages constructed upstream of Medigadda under the Kaleshwaram Project, viz. Annaram and Sundilla barrages, have similar designs and construction methodologies, making them prone to similar failure modes.
Signs of boiling already exist downstream of Annaram Barrage, a precursor to failure. These barrages also should be examined urgently for signs of piping/ distress.