Vigilance report ‘Gross negligence’ led to Medigadda failure

The Vigilance and Enforcement Department’s preliminary enquiry report into the failure of the Medigadda Barrage attributed it to ‘gross negligence’ by the contractor L&T.
The report said, “The cofferdams along with sheet piles formed during the construction of the barrage had to be removed to operationalize the barrage. But the cofferdams connected sheet piles and RR pitching were not removed even after five seasons which might have affected the natural flow of the river.”
The report says that no maintenance was carried out on the Barrage. Neither the department nor the contractor took up restoration of the damaged portion of the wearing coat, downstream apron etc. Project authorities have not inspected or maintained CC blocks or launching aprons after the commissioning of the barrage in 2019-20. This is a significant maintenance issue.
CC blocks have been dislodged and they also damaged the parametric joint of the plinth slab which was noticed in November 2019, making the barrage susceptible to piping and subsequent failure.
It implies that the negligence of the dam owners has made the barrage susceptible.
As per excerpts of the report, the connection between the cut-off walls and raft has to be cast scrupulously as per approved drawings.
After inspection of the site, the connection between cut-off walls and raft might have not been casted as per drawings and the primary piles might have been damaged during the casting of secondary secant piles which might have caused undermining.
V&E noted that in the physical cracks observed from Piers No: 16 to 21 of Block-07, there might have been shear failure of the raft due to the escape of raft supporting material.
As per the recommendations of the 3D study, before bringing the barrage into operation, the upstream and downstream over burden has not been trimmed to the specified levels as per the recommendations of the 3D Model study.