PNS|Hyderabad
The National Dam Safety Authority (NDSA) has sounded a warning over the safety and sustainability of the Kaleshwaram Lift Irrigation Project’s key components — the Medigadda, Annaram and Sundilla barrages — after a committee of experts exposed lapses in its design, construction and quality control.
The Committee’s report, finalised in December 2024 and chaired by former CWC Chairman J. Chandrashekhar Iyer, reveals that all three barrages are facing structural distress, with Medigadda’s Block 7 on the verge of collapse due to piping-induced subsidence.
The report warns that undiscovered holes in the cut-offs across all the three barrages could trigger future failures, demanding a comprehensive geotechnical reassessment, structural modelling, and rehabilitation.
The Committee noted that Medigadda’s Block 7 sank due to unchecked transport of sub-soil particles, exacerbated by the failure of secant pile cut-offs — a failure rooted in poor quality control and lack of proper sealing during construction.
Block 7 of the Medigadda Barrage — where piers 16 to 21 sank and tilted — is the epicentre of the crisis. The Committee attributes this to the uncontrolled movement of sub-soil due to piping, worsened by the absence of water-tight cut-off walls.
Cracks ranging up to 300 mm, reinforcement failures, and distortion in the gantry structure were found. Satellite imagery showed silt build-up and inactivity of spillway gates around pier 17, indicating improper usage and the lack of timely intervention. Contrary to initial claims, the sweep-out of the hydraulic jump was ruled out as a cause.
The construction of all three barrages began while the Detailed Project Report (DPR) was still under appraisal by the Central Water Commission. Despite this, the locations of Annaram and Sundilla were altered without any geotechnical investigation — a decision taken by a High-Powered Committee of the Telangana I & CAD Department.
Changes in pond levels and barrage capacities were also pushed through without informing the CWC, breaching technical protocols and resulting in unstable structural choices.
Both upstream barrages — Annaram and Sundilla — exhibit repeating symptoms: dislodged concrete blocks, washed-away wearing coats, and re-emerging seepage despite frequent grouting.
The secant pile cut-offs in these barrages weren’t designed to handle the structural moments transferred from the raft, leading to cracking of the joints and continuous vulnerability to failure. PU grouting — the primary quick fix — has become a band-aid applied repeatedly, but the root structural integrity remains compromised.
