ROAD CLEARING. Personnel of the Department of Public Works and Highways conduct clearing operation in the lahar-hit main road of Barangay Biak na Bato in La Castellana, Negros Occidental early Thursday morning (June 6, 2024). The road is now passable, but the Philippine Institute of Volcanology and Seismology (Phivolcs) advised residents to increase vigilance for their safety. (Photo courtesy of Cheng Santillan)
BACOLOD CITY – The main road hit by lahar in Barangay Biak na Bato of La Castellana, Negros Occidental, was cleared a day after rains triggered lahar flow in the village situated at the foot of Mt. Kanlaon on Wednesday.
However, the Philippine Institute of Volcanology and Seismology (Phivolcs) advised residents to increase vigilance for their safety.
In its latest advisory, Phivolcs said “lahars can threaten communities along the middle and lower slopes with inundation, burial and wash out”.
It “strongly recommends increased vigilance and readiness of communities along rivers draining southern Kanlaon”.
“These communities and local government units (LGUs) are advised to continually monitor weather conditions and take pre-emptive response measures for their safety from potential lahars,” the advisory said.
Since Wednesday night, personnel of the Department of Public Works and Highways (DPWH) have been clearing the main road of Biak na Bato and remained in the area Thursday to ensure the safety of motorists.
In a radio interview Thursday, Provincial Environment and Natural Resources Office head Joan Nathaniel Gerangaya, whose team has been monitoring and assessing areas affected by the volcanic eruption, said that with the quick reaction of the LGUs, the area is now passable.
“Vehicles can now pass through the road, but the cleanup may take a long time. The ashfall can also harden. The challenge is now for the DPWH to clear up the waterways. It’s possible when there is heavy rain and typhoon, it could cause flood,” he added.
Phivolcs said thunderstorms early afternoon Wednesday “generated volcanic sediment flows or lahars on the southern slopes that were detected by three seismic stations of the Kanlaon Volcano Network (KVN)”.
The lahars began around 1 p.m. and lasted for about 25 minutes based on the seismic record.
These were “generally channel-confined, but flows along Tamburong Creek overflowed and dumped a few centimeters of deposit on a stretch of the main road in Biak na Bato, rendering this impassable to motorists”.
According to Phivolcs, grey cohesive mud, plant debris and gravel have been deposited by lahars in at least four waterways.
These include Tamburong Creek, which courses through Biak na bato and Calapnagan, La Castellana; Intiguiwan River in Guinpanaan and upstream Baji-Baji Falls in Cabacungan, La Castellana; Padudusan Falls, Masulog, Canlaon City; and the Binalbagan River, which drains the southern flank of Kanlaon Volcano.
On Thursday, thunderstorms could bring heavy rains over Negros Island and rains could generate lahars, muddy streamflows or muddy run-off in the above-mentioned and other rivers draining the southern Kanlaon edifice, Phivolcs added. (PNA)
