Cracks on Topaz Road due to old drainage system giving way due to rainfall —MGB

The cracks found on Topaz Road in Ortigas Center in Pasig City may be due to the old drainage system giving way after heavy rainfall poured, the Mines and Geosciences Bureau (MGB) team that inspected the area said.

"Sa tingin ko wala nang iba (In my opinion, there is no other cause). It’s the heavy rainfall, the pressure from the rain [that caused the cracks]," MGB supervising science research analyst Liza Manzano told GMA News, according to a report on Unang Balita on Wednesday.

"Ang nangyayari, 'yung mga sandy materials na mahina, 'yun 'yung wina-wash out ng tubig. That’s a natural thing, puwedeng mangyari. But puwede rin, kung meron kang mga pipes sa ilalim, na through time nag-deteriorate, nag-leak at magbu-burst," she added.

(What happened was the sandy materials were washed out by water. That's a natural thing, it can happen. But it is also possible, if you have pipes underneath, that through time these will deteriorate, leak and burst.)

The MGB team said the road cracks do not pose a danger for now but these should be monitored.

They added that the MGB will issue a recommendation in three days regarding the rehabilitation of the road.

The Pasig City Hall meanwhile said it will issue certificates of inspection to the buildings nearby to give assurance that the area is safe.

Plugging of the drainage started on Tuesday night to divert the water and avoid having it flow through the cracks.

A reinforcement wall will also be built to prevent further erosion.

Topaz Road has been closed to motorists starting Sunday night when the cracks first appeared.

The Philippine Institute of Volcanology and Seismology earlier said the cracks are not due to a faultline.

City engineers found that the surge of water from the old drainage system damaged a portion of the road. —KG, GMA News