A 25% cost reduction was possible thanks to our permanent solution to protect the banks of the Vennar River, in the state of Tamil Nadu
Temporary restoration works were not stopping landslips on the banks of the Vennar River. The local authorities were considering a reinforced concrete wall to protect the river banks until we proposed a permanent solution using our gabions and Reno Mattresses. The project was successfully completed with a 25% cost reduction.
The Vennar River is a tributary of the Kaveri River, located in the South of India. It passes through the Trichy and Thanjavur regions of Tamil Nadu. In November 2011, a landslide affected one of the banks of the river over a length of about 250 metres above the Saliamangalam-Papanasam road bridge at the 49/2-7th mile. The event was caused by heavy downpours during the North-Eastern monsoon and the earth bund was totally washed away by the flood water. The bund used to serve as an approach road for the nearby villages and the event caused disruption to the local traffic. Temporary restoration works were carried out regularly, but repeated slides during every monsoon forced the Public Works Department (PWD), Govt. of Tamil Nadu, to opt for a permanent solution to protect the river bank.
Our cost-effective solution included a 4.5m-high gabion retaining wall and 4m-wide mattresses on both river banks over a length of 500 metres, to provide bank protection as well as erosion control of the river bed. The solution has the advantage of being flexible, durable and self-draining when compared to the conventional reinforced concrete retaining walls.
A cost analysis showed that a 25% reduction was achieved with our gabions and mattress structures instead of the conventional concrete solution.
The project was successfully completed and our structures met all the project requirements. In fact, our gabion structure withstood two complete irrigation periods and no settlements were observed. The structure also ensures an uninterrupted supply of irrigational water during the monsoon season to almost 95,000 hectares of land in the lower reaches of the Vennar River. The approach road over the retention structure re-established a safe connection between the villages of Kalanjeri, Konur and Kovathukudi.
For more information, download our case history.