Goa: Galgibaga river changes course, locals worried about flooding in low-lying areas

POINGUINIM: In a major natural or Cyclone Tauktae-induced development, the Galgibaga river has changed its course while separating from its smaller twin, the Mashem river, on the sea face. It now flows directly into the Arabian Sea.
The Mashem river flows zig-zag, a short distance from Loliem in the south-east. Canacona taluka’s second biggest river, the Galgibaga, originates in the Western Ghats and flows westward, curving south to join the smaller river for the short gush to the sea.
Galgibaga’s diversion to the left, near the sea, was necessitated by the formation of a spit - a tongue of sand - since hoary times, blocking its access. This natural barricade was partly broken in May, during the turbulent Cyclone Tauktae.
Experts say that the sandbar along the Galgibaga has been subjected to erosion for a long time, mostly due to rough sea conditions and storm surges. “The sandbar was first breached at many places in August 2020 by Cyclone Vayu. The leftover sandbar was completely devastated by Cyclone Tauktae, resulting in the opening of a new channel,” senior geographer F M Nadaf told TOI.
Previously, the interaction of the Galgibaga with the Arabian Sea was through the Mashem creek, but now, due to the opening of this new channel, it is directly interacting with the sea, Nadaf said. “It was observed that during the last spring tide, the level of water in the Galgibaga was higher than the May 2021 period. This resulted in panic among locals.”
On Thursday, villagers were stunned to see strong waves dismantling the remnants of the sandy barrier, flattening more than 100m of it and carving out a new channel of about 15m for direct flow.
“The damage to the tongue of the spit was hardly 50m and easier to fill up, but the authorities concerned ignored the matter. Huge sea waves are now directly entering the river creating dangerous currents,” Mashem resident Manoj Prabhugaonkar said.
The confluence of the two rivers on the sea face - something quite rare - was exactly what made these two rivers important and created a breathtaking view, especially at sunset.
Now, however, the unprecedented opening has triggered panic as locals are apprehensive about flooding of low-lying houses at Mashem jetty and nearby. Just last week, a local fisherman almost drowned after his canoe capsized due to strong currents. The flow in the river has also resulted in the mangroves on the Mashem side gathering more sand and muck.
The river changing its course could be disastrous to the ecosystem and local residents on its bank, villagers said. “This needs a high-level study or the mangrove cover will disappear completely, exposing the river bank to tidal currents, sea waves and floods in the rainy season” another local, Matilda Dias, said.
Half a century ago, the confluence of the Mashem-Galgibaga rivers - that created an extensive channel between two rivers - was a thriving port, some elders said. Ships coming with goods from as far as China would dock here. “The creek was more than 10m deep,” a senior villager said.
But, two decades back, the public works department’s (PWD) decision to reclaim the river along the eastern bank of the channel choked the flow and increased siltation. The villagers stopped the mud dumping for a bridge, but the damage had partly been done. PWD abandoned the work, but did not clear the embankment. “A sand bar which formed later made the river mouth shallow, affecting its ecology,” a villager said.
In recent years, PWD took up and completed the highway expansion, reclaiming more area of the river. “All this will have an irreversible impact on the rivers’ ecology,” Prabhugaonkar said.
“The threat to life and property will increase when spring tide and heavy rainfall like that of 2009 (Canacona disaster) transpires,” Nadaf said.