Thousands evacuate ahead of Pinatubo lake draining

BOTOLAN, Zambales — Some 40,000 residents of this town’s 18 barangays are set to abandon their homes and move to evacuation centers today as scientists prepare to drain a massive crater lake threatening to overflow from Mt. Pinatubo.

At least 16 dump trucks from Zambales, 10 from Victory Liner, three each from the Department of Public Works and Highways and the governor’s office arrived here yesterday for those who would want to evacuate early.

Residents of Barangays Panas and Binuklutan, however, would not be evacuated since their areas are protected by the Bucao mountain ranges from possible lahar flows that could be generated by the release of water from the crater lake.

A group of Aeta tribesmen had been working with public works engineers in building a canal on the edge of the volcano to release some 24 million cubic meters of water on Thursday, said Raymundo Punongbayan, chief of the Philippine Institute of Volcanology and Seismology.

A massive eruption gouged out the top of Pinatubo in 1991, creating a 2.5 kilometer wide lake that now holds some 210 million cubic meters of water.

With the onset of monsoon season, experts warned in August that the lake could overflow in two months and wash away surrounding towns.

The plan called for a controlled release of the lakewater to ease its pressure on the crater wall of the 860-meter volcano.

Punongbayan said local officials had been told of the plan to drain the lake, and that residents near the volcano would be evacuated.

"The water is expected to spill out very fast, but I think it is safe," Punongbayan said, adding that the canal’s base is supported by hard rock "stronger than concrete."

"We hope it will not be washed out," he stressed.

He said the water was expected to mix with ground sediment to transform a deadly cocktail of lahar that is expected to be contained in a river channel north of the volcano.

Experts had warned that a sudden gush of the dammed water in Pinatubo could flood the entire town of Botolan, about 40 kilometers northwest of the crater.

"We don’t see it happening like that. It would take time before it could carve a wide and deep channel," Punongbayan said.

Evacuation of residents "will be done tomorrow. I think we are talking in terms of over 40,000 people in Botolan and various other towns," he said.

"We are ready to release the water on Thursday morning at seven in the morning," Punongbayan said.

A similar project had been successfully carried out in Indonesia’s Kelut volcano, Punongbayan noted even as he said Pinatubo was about five or six times bigger.

If everything goes smoothly, breaching of the excess water could take anywhere between five or six hours to several days, he said.