HYDERABAD: On Thursday, the second day of its tour, the expert committee of the National Dam Safety Authority (NDSA) focused on the aspects of designs of the Kaleshwaram Lift Irrigation Scheme during its interaction with state Irrigation officials here.
According to sources, the team, headed by Chandrasekhar Iyer, asked about the drawing of designs and the operation and maintenance of the Medigadda, Sundilla and Annaram barrages.
It may be recalled that the NDSA’s preliminary report prepared after the sinking of the piers of the Medigadda barrage said that there were some flaws in the designs.
The team interacted with the officials of the design wing, project construction authorities, operation and maintenance wing, investigation agencies and construction agencies. The team also elicited information on quality control aspects.
The team interacted with key officials individually. The committee also had discussions with the then engineer-in-chief C Muralidhar.
The team members also asked about the possible reasons for the sinking of the piers of Medigadda barrage. They asked about the surveys done for the projects, including Lidar survey.
The officials informed the team that they carried out model studies on the Annaram barrage after they noticed leakages in 2019.
As per the model study, the causes were assessed for damages of energy dissipation arrangement. The shooting flows/seepages are due to inadequate tailwater levels, especially during the transitional stage during the low flows, the model study said.
It said that due to the inflow pattern in the barrage, it is required to release such low flows with a full head of 15 m and partial openings of the gates leading to high velocities of flows on the cistern and protection works downstream.
Model studies on Annaram barrage
The officials informed the NDSA team that they carried out model studies on the Annaram barrage after they noticed leakages in 2019. The causes were assessed for damages of energy dissipation arrangement. The shooting flows/seepages are due to inadequate tailwater levels, the study said.
