This, as scientists continue to observe how the flow of water through a man-made canal would affect the stability of the crater wall facing this town.
Municipal administrator Elrin Rico said residents of Barangays San Juan, Paudpod, Karael, Pako, Bangan and Porac were advised to be ready for evacuation anytime because their communities are low-lying and located near the Bucao River.
Volcanologist Jaime Sincioco said the artificial breaching through the canal dug up by Aeta workers at the crater’s lowest point — the so-called Maraunot notch because it leads to the Maraunot River which drains into the Balin-Baquero and Bucao rivers — has dissipated immediate threat to Botolan villages.
"But there is still the long-term danger that we have to face," Sincioco said, adding that the flowing lake water can weaken the "binding material" that holds hard rocks together in the Maraunot notch.
"We still do not know when this could happen. That would depend on the erosion rate at the canal and the rains that could affect the volcanic summit," he said.
Thus, Sincioco said residents of the six barangays should be ready for evacuation should rocks at the Maraunot notch give way.
Some 40,000 people from 11 Botolan barangays were evacuated during the artificial breaching but were allowed to go home two days later.
Sincioco said watchpoints equipped with communications equipment are monitoring the situation so villagers could properly be warned in case of contingencies.
He said it would take about one and a half hours for rocks from the Maraunot notch to cascade down the six barangays. "They would have enough time to evacuate," he said.