The Philippine Institute of Volcanology and Seismology (PHIVOLCS) issued an urgent advisory Friday morning, Feb. 6, warning that heavy rains brought by Tropical Depression “Basyang” could trigger life-threatening volcanic sediment flows, or lahars, around Kanlaon Volcano.
Currently maintained at Alert Level 2, the volcano faces the risk of sediment-laden streamflows, muddy run-off, and siltation in rivers and drainage areas, it said.
Phivolcs recommended increased vigilance and immediate readiness for communities situated within pre-determined hazard zones as the cyclone impacts the Visayas region.
The agency said that prolonged heavy to intense rainfall may generate these dangerous flows on major channels draining the southern, western, and eastern slopes of the volcano.
Post-eruption lahars are a primary concern, as intense rainfall can easily erode loose material from remnant pyroclastic density current deposits left by the Oct. 24, 2025, explosive eruption, Phivolcs said.
This risk is further compounded by loose ashfall from that event as well as more recent ash emission activities that remain settled on the volcano’s slopes, it added.
Phivolcs also warned of “non-eruption” lahars triggered by environmental damage from previous disasters. Areas on the upper slopes that were recently exposed by landslides or structurally weakened during the passage of Supertyphoon Tino in t November have become highly susceptible, it said.
These weakened slopes can feed massive amounts of debris into river systems that have delivered destructive flows to downstream communities in the past, it said.
Several communities in both Negros Occidental and Negros Oriental have been identified as high-risk areas.
Specifically, residents in Bago City, La Carlota City, La Castellana, Moises Padilla, and San Carlos City in Negros Occidental, along with Canlaon City in Negros Oriental, are at risk, Phivolcs said.
These areas are situated along critical channels including the Ibid, Cotcot, Talaptapan, Malaiba, Panubigan, Buhangin–Indurayan, Najalin, Inyawan, Maragandang, Panun-an, Intiguiwan, Camansi, Maao, Tokon-tokon, Masulog, Binalbagan, Taco, and Linothangan rivers and creeks.
Phivolcs has advised these communities, as well as those further downstream, to be prepared for evacuation if necessary and to strictly avoid traversing affected streams, even those located farther downslope.
The agency reminded the public that Kanlaon lahars—previously proven during Supertyphoon Tino to be powerful enough to transport enormous volumes of gravel and boulders—pose a severe threat through force of impact, inundation, burial, and washout.
Local government units and residents are urged to continually monitor rainfall conditions and take proactive pre-emptive measures for their safety, Phivolcs said.*
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