Colva, Jan 3 (TOI): High tidal waves have led to removal of sand dune sediments, allowing seawater to chart its own course beyond the beaches at certain stretches spanning from Colva to Benaulim. At many places, water ingressed into the sandy turf leading to a 'well formation'.

The phenomena are more noticeable at Colva and Sernabatim, where tourists flock in large numbers. A fisherman tending to his nets said, "Well formation could be due to whirlpoola caused by a sudden surge of water.''

Antonio Mascarenhas, an expert on sand erosion, attributed the water ingress to 'wave-cut scarps' that normally happen during monsoons. "The recent changes could be possibly due to some abnormal behaviour of the wind or waves at that time,'' he said.

"Well formation could be due to removal of sand by someone, which worsened due to the marine action. It's strange that turbulent activities are witnessed post-monsoon too,'' he said.

Another expert Virupaxa Banakar said the well formation could be due to circular sand triations, which develop only when the water is rotating. During high tide, a lot of energy occurs and water course is blocked, and redistribution assumes the form of rotating water leading to soil erosion.