VIJAYAWADA: Once Chief Minister N Chandrababu Naidu releases the work schedule for the Diaphragm Wall of the prestigious Polavaram Irrigation Project on December 16, the construction of the D-Wall will commence in the first week of January.
According to highly placed sources, the construction of the 1,400-metre-long D-Wall will be taken up in a phased manner as per the recommendation of the committee of experts. The new D-Wall designs were approved by the Central Water Commission (CWC) in the last week of November.
The new D-Wall, which is estimated to cost around Rs 900 crore, will be constructed by MEIL, in collaboration with Bauer Group of Germany, and it is expected to be completed by March 2026, if not by December 2025.
Incorporating the suggestions of the international committee of experts, the new D-Wall will be constructed some 6 metres upstream of the existing D-Wall, which was damaged during floods in 2019 and 2020.
According to experts, the D-Wall will be a sub-surface construction going to 2 metres in depth beneath the rock strata below the river bed. Rock strata is found at varying depths in the river bed of Godavari at the location of the proposed D-Wall. The depth varies from 40 to 90 metres. The proposed D-Wall is a single structure to be constructed parallel to the old one.
The executing agencies are at present busy with the construction of platforms to take up the excavation for the D-Wall construction using specialised machinery -- cutter and crab machines -- which will be brought by Bauer from Germany. To ensure uninterrupted work, the platforms are being constructed at a height of +20 metres
The international experts’ team, which studied the scoured portions of the project, and other aspects, is likely to examine, and submit its recommendations to the CWC by February for its approval of the Earth Cum Rock Fill (ECRF) Dam.
Works of the ECRF Dam Gap 1 are likely to be taken up in March next year, and Gap 2 in November.