KLIS Barrages Need Extensive Repair: NDSA
NDSA made it clear that irrigation department engineers will have to go back to their drawing boards if these barrages were ever again to be put to use
HYDERABAD: “Extensive debilitating damages.”
With these three words in its 378-page report on the state of Medigadda, Annaram, and Sundilla barrages of the Kaleshwaram Lift Irrigation Scheme, the National Dam Safety Authority issued a damning indictment of planning, executing, constructing, and maintaining the three barrages, the lifeline of the Kaleshwaram project.
It may be recalled that KLIS was in many ways, was claimed as the crown jewel of its achievements by the then BRS government during whose regime the entire project was planned, designed, built, and put to use. However, after the October 2023 cracking and sinking of the Medigadda barrage, the NDSA entered the picture, and in its final report to the Telangana government on Thursday, the Authority concluded that in view of “the extensive debilitating damages suffered by the three barrages,” the entire structures require a “holistic rehabilitation design, comprehensive assessment of health and safety.”
It further made it clear that the condition of the barrages was such that they require “immediate stabilization measures” adding that they are experiencing “ongoing distress.”
In short, the NDSA made it clear that irrigation department engineers will have to go back to their drawing boards if these barrages were ever again to be put to use. And that they do not have much time to lose.
The NDSA said all three barrages, Medigadda, Annaram and Sundilla, had construction defects, design deficiencies, structural distress resulting in the phenomenon of sand piping, cavity formation underneath the raft, and other downstream damages rendering them “unserviceable.”
It further warned that the damages seen in Block 7 of Medigadda, which cracked and sank, could manifest in other blocks of the barrage as well. “The two upstream barrages at Annaram and Sundilla, which have similar deficiencies in design and construction, have also experienced distress conditions and damages rendering them unserviceable.”
The NDSA said all the three barrages were vulnerable, can experience catastrophic failure, and hence, they need to be thoroughly and entirely investigated in right earnest.
Even more damaging to the then government which oversaw the entire Kaleshwaram project, and all the engineers involved in its various aspects and phases, the NDSA raised the question of ethics that were probably given a go by saying “in the larger interest, it is important that engineering ethics take lead, and no bias creeps into the investigations and studies.”
The NDSA also practically castigated the irrigation department for not exhibiting the “desired pace and urgency… serious gaps, particularly in the sequencing of investigations,” it recommended in its interim report. These factors such as premature grouting activities, “irreversibly altered critical subsurface geotechnical conditions underneath the raft and along secant pile cutoffs,” the report said, explaining that this hampered the NDSA’s ability to “evaluate the original ground conditions and state of the structures effectively.”
It said based on “the inferences drawn from the series of investigations and studies, a suitable rehabilitation plan must be designed and implemented.” It recommended that the irrigation and command area development department “consider utilising the services of the best institutions/research stations/departments in the country for investigations and rehabilitation design.” It also said given the complexity of the task ahead, “the formulated rehabilitation design may preferably be reviewed by the Central Water Commission.”
The report also raised serious questions on the model studies for the three barrages saying they were found to have lapses, and hinted that these studies did not factor in “real-world hydraulic conditions to enhance the efficiency and safety of the structures.”
NDSA findings
Medigadda Barrage
Damages to Block 7 made the barrage non-functional. Even the bridge spanning the barrage is non-functional. Due to sinking, Block 7 suffered irreversible damages, and its safe removal poses challenges as it may cause damage to adjacent blocks.
Cavities similar to the ones found under Block 7 might be present in other blocks too and can lead to sinking/development of cracks and damages in the rest of the barrage.
Since Block 7 cannot be used, it may be safely disposed or stabilized based upon the experience and expertise of the executing agency. The chosen option should not damage the adjacent blocks in any way.
