NDSA picks holes in construction of Kaleshwaram’s Main barrages

Hyderabad: The NDSA (National Dam Safety Authority) has found that the designs of the Kaleshwaram lift irrigation scheme – mainly the three barrages –Medigadda, Annaram and Sundilla are faulty and that the absence of quality was visible in the construction of the barrages.

The NDSA has submitted a 350-page final report on the damage of the three barrages to the state government. The report explained the details of the status of the barrages and the reasons for the damage of the structures within two years after the commissioning of the Kaleshwaram project.

The report said that the Medigadda barrage, the first in the series, suffered from severe settlement and cracking of piers in Block-7, with notable tilting, structural and hydro-mechanical compromise due to piping, deterioration of energy dissipation structures including dislodgement of wearing coat, and cement concrete blocks downstream.

The Annaram and Sundilla barrages exhibited similar patterns of seepage/piping distress including the dislodgment of wearing coat and concrete blocks downstream. The observed damages and distress in the three barrages raised serious concerns about the resilience of these structures under operational and environmental stresses, the NDSA report explained. “The upstream barrages, Annaram and Sundilla, which exhibit similar design and construction flaws, have experienced structural distress and damage, rendering them unserviceable. All three barrages require comprehensive investigation from multiple angles”.

Block 7 of Medigadda barrage has suffered irreversible damage with cracked and displaced piers and rafts. The Committee recommended that this block not be used for gate operations again. It may either be safely decommissioned or stabilised in-situ, without affecting adjacent blocks, it said. Cavities beneath the raft must be completely filled. As this could alter the foundation conditions, a fresh structural analysis using FEM software, considering soil-structure interaction, is advised. Instrumentation should be installed across the barrage—three piezometers per bay at the upstream, middle and downstream points. Other instruments proposed in the rehabilitation plan must also be included. Continuous monitoring of data is essential to detect abnormal structural behaviour early, the report said.Kaleshwaram Project, NDSA Report, Barrage Structural Damage, Medigadda Annaram Sundilla, Dam Safety India, Telangana Irrigation Crisis