Ponda: After finding that a major part of the Opa river has eroded and has a deep ravine under water near the barrage at the Opa Water Works, the water resources department (WRD) has taken up construction of a retaining wall to prevent further erosion.With regard to the deep ravine formed under the river basin, the WRD contractor has been laying over a metre-wide square concrete block, which would be placed inside the ravine to fill the level of the basin.WRD assistant engineer Pandharinath Lawande said the work has been taken up to prevent further damage to the riverbank and the basin, especially during the monsoon. With the overflow of water during the monsoon, WRD opens barrage gates to release excess water.“The released water flows at high pressure and erodes the riverbank and also washes away the basin soil, creating a deep ravine. This is a natural phenomenon,” Lawande told TOI. The 8m high and around 40m wide barrage has six gates that can hold water up to 8m.The tender for the retaining wall and concrete blocks has been allotted to Unique Construction, Quepem, at a cost of Rs 5 crore. Lawande said the work would be completed before the monsoon.The WRD does not open the first and last gates of the barrage during the monsoon to avoid further erosion of the river
