Volcano villagers return home

MANILA, Philippines (CNN) -- Thousands of villagers evacuated from the slopes of Mount Pinatubo in the Philippines have begun returning home after being given the all clear by engineers working to drain a lake in the volcano's crater.

Some 40,000 residents were evacuated from the foothills of the volcano earlier in the week amid concerns that the crater wall might give way during the draining operation creating deadly flash-floods.

However, with the water beginning to seep out along a specially dug channel Friday, officials said they were confident it was safe enough for local residents to go home.

"The greater majority of the evacuees have been allowed to return home," General Melchor Rosales, executive officer of the National Disaster Council, told CNN.

"Those left behind are those living close to the river bank and they have been advised to stay put," he added.

President Gloria Macapagal-Arroyo is expected to visit those people remaining in the evacuation centers later on Friday.

Overflow fears

Government geologists and engineers began moves to drain the massive lake within Mount Pinatubo's crater following fears that annual monsoon rains from June to October would cause the lake to overflow.

Before the operation began the water level was just a few meters below the lake's rim.

Engineers are planning to drain off a tenth of around 210 million cubic meters of lake water to decrease the pressure on the crater-wall.

The water is being channeled through a 75-meter-long man-made canal on Pinatubo's slope, down to a flood plain, river tributaries, and westward to the South China Sea.

The draining began Thursday but started as little more than a trickle because the channel had not been excavated at a sufficient angle.

By the end of the day officials said further excavation had increased the outflow to 1,800 cubic meters per hour.

"It's a good success story... it's something that we can be proud of," vulcanology institute chief Raymundo Punongbayan was quoted by local television.

"There was zero damage to people or property."