The water resources department (WRD) has initiated construction of a retaining wall at the Opa Water Works in Ponda after discovering significant erosion and a deep ravine beneath the river near the barrage. The work aims to prevent further damage to the riverbank and basin, particularly during the monsoon season.
Details of the Construction
To address the deep ravine formed under the river basin, the WRD contractor is laying over a metre-wide square concrete blocks that will be placed inside the ravine to fill and level the basin. WRD assistant engineer Pandharinath Lawande explained that the project is essential to protect the riverbank and basin from further deterioration, especially when monsoon rains cause increased water flow.
Cause of Erosion
During the monsoon, the WRD opens the barrage gates to release excess water. The released water flows at high pressure, eroding the riverbank and washing away basin soil, which creates deep ravines. Lawande described this as a natural phenomenon. The barrage, which is 8 metres high and around 40 metres wide, has six gates capable of holding water up to 8 metres.
Project Details
The tender for the retaining wall and concrete blocks has been awarded to Unique Construction, based in Quepem, at a cost of Rs 5 crore. Lawande confirmed that the work is expected to be completed before the onset of the monsoon. To minimize further erosion, the WRD avoids opening the first and last gates of the barrage during the monsoon season.
