Work to fill gaps in foundation structure of Almatti dam begins

Almatti (Bagalkot dist): Renovation and repair work of the foundation of the Lal Bahadur Shastri dam across River Krishna here has begun in right earnest by using state-of-the-art technologies. 

The process is aimed at increasing the longevity of the underwater concrete structure of the dead storage and works have been initiated in the backwaters of the key reservoir in the state. 

The work is part of the Dam Rehabilitation and Improvement Project (Drip-2) framed by the Central Water Commission and is being undertaken with a Rs 28-crore financial aid provided by the World Bank. 

The renovation work of the part above the dead storage of the dam has already been undertaken under Drip-1. 

The dead storage of the reservoir stands at 506.8 metres from sea level and stores 17.6 tmc ft of water below it. 

This phase of the renovation work is aimed at reducing water loss due to seepage from the almost 18-metre gap between the foundation that stands at 488 metres and the dead storage level of 506.8 metres, D Basavaraj, incharge chief engineer of the dam zone at Almatti (Krishna Bhagya Jala Nigam Limited), told DH. 

Works will be undertaken using latest technologies for a length of 1.2 km. They have been taken up for the first time since the construction of the reservoir using best practices from across the world. A special purpose cement and a mixture of gypsum, polymers and epoxy resin is used in the process. 

As many as 20 workers, including underwater divers, have been deployed for the work and they will climb down into the water from a platform tied to ropes. They will be equipped with oxygen cylinders and tools required for the job.

The workers will wear protective gear so that they aren’t harmed by crocodiles or other aquatic beings. 

They will undertake crystalline waterproofing by filling the gaps, pores and holes in the dam structure with the special mixture, which hardens in just 10 to 30 seconds, assistant engineer Vithal Jadhav told DH. 

Grouting technology that uses a jet device is deployed to fill a mixture of gypsum, polymers and epoxy resin vertically into gaps that are deeper than one metre.

Preventing seepage will help increase the reservoir’s storage capacity.

Cut-off box - Brief history of the dam
The Almatti dam gets its name from former prime minister Lal Bahadur Shastri.
It was Shastri then the union water resources minister who laid the foundation stone for the dam in 1964.
However the work on the reservoir was completed only in 2000 and water was stored to full reservoir level in 2002.
The dam having a capacity of 123.081 tmc ft gets up to 3 lakh to 4 lakh cusecs of water a day during peak monsoon.