Andhra Pradesh

Cofferdam issue: end to stalemate in sight

Experts have suggested that water could be diverted into the canals by building the main earth-cum- rock filled dam and constructing a temporary dam to bridge the gap.  

Experts of the National Hydro Power Corporation (NHPC) have come up with a “via media” solution to the Polavaram cofferdam problem raised by the Union Ministry of Water Resources.

The experts, in a report to the Central government, have suggested that water could be diverted into the canals by building the main earth-cum-rock filled (ECRF) dam halfway into the Godavari and then constructing a temporary dam to bridge the gap. The ECRF dam could be completed in the subsequent season.

This seeks to end the controversy triggered by the Ministry on November 1, when it wrote a letter asking the State government to “put on hold” the work pertaining to the building of the cofferdam that was needed for the construction of the ECRF dam.

The Central government had also written to the NHPC, asking it to suggest ways to build the Polavaram dam without the cofferdam to “economise both material and cost in construction of the dam.”

The Central government had also asked the NHPC to look into the possibility of designing the ECRF and cofferdam in such a way that the cofferdam was integrated into the former.

The NHPC was also asked to look into the possibility of constructing the ECRF dam up to a safe flood level in one season and doing away with the construction of the cofferdam altogether.

The NHPC has come up with the via media solution by suggesting the beginning of the construction of the ECRF dam and bridging the gap with a temporary dam to impound enough water for it to flow into the canals by gravity, in one season.

In this way, water could be sent by gravity into the Polavaram project canals both the seasons.

The building of the ECRF dam halfway into the river and then filling the gap with a temporary dam could be achieved in one season (seven working months) with meticulous planning, said a senior irrigation engineer.

All human habitations within the +41.15 metres contour had already been cleared and water could be impounded until that level in the first season. This would allow sending of water into the project canals by gravity and save up to 70 tmcft, the engineer said.

Water only in 2019?

Chief Minister N. Chandrababu Naidu had already said that it was not possible to send water by gravity in 2018. The five months left was not sufficient to complete the work on the ECRF dam and the temporary dam. Completion of the spillway to the height of +41.15 metres contour level was essential to impound water. While the fabrication of radial gates had been completed, a lot concrete work still needed to be done.

Petition against Transstroy

A nationalised bank has filed a petition in the National Company Law Tribunal (NCLT) demanding that the prime contractor of the project, Transstroy, be declared insolvent.

The firm owes the bank ₹725 crore. While the outstanding is ₹490 crore, the contingent liability is to the tune of ₹380 crore.

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Printable version | Feb 28, 2021 4:32:25 AM | https://www.thehindu.com/news/national/andhra-pradesh/cofferdam-issue-end-to-stalemate-in-sight/article22335328.ece

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