EVACUATION PUSHED: Houses built above old tunnels

CEBU, Philippines - The Mines and Geosciences Bureau recommended a temporary evacuation of the residents of Salinas Drive in Barangay Lahug whose houses are identified, during the inspection last week, to be built atop the 12 other tunnels, possibly interconnected to the one that collapsed recently.

Al Emil Berador, MGB-7 chief geologist, said that the 12 other tunnels were identified based on the testimonies of the residents who claimed that they themselves discovered a hollow portion below when they were constructing their houses specifically the septic tanks.

“Based sa interview, pagkawot sa foundation o paghimo sa ilang septic tanks, nahulog ilang equipment. So ang uban, mao na lang to ang gihimong septic tanks,” Berador said.

“Aware na sila nga naa na. Na-highlight lang karon tungod sa nahitabo sa usa ka tunnel na ni-collapse. Kay possible na mu-collapse sad ang ubang tunnel especially karon na sige’g ulan,” he added.

Berador said that the residents were already warned of possible scenarios and asked to be vigilant if ever they observe movements on the ground or cracks on their floor. “Dapat i-report dayon na nila sa mga opisyal aron maaksyonan ug matan-aw unsa’y angay na buhaton.”

The possibility of another cave-in is now higher because of the collapse of the 12-meter tunnel, believed to be constructed during the World War II by the Japanese invaders, last June 9.

That area in Salinas Drive, according to Berador, sits on a type of rock that is Pliocene-Pleistocene Carcar formation. It consists of porous coralline limestone.

“Tingali sa kadugay na nga panahon, unya gihimo pa gyud nila nga septic tank and given the same condition as last time na sige’g ulan, pwede gyud sya mag-ground collapse anytime,” Berador said.

He said that even if the height of the tunnel is only at three to five meters, it is still risky for residents because most of the houses in the area are made of concrete materials.

“Pwede gyud na makapatay kung pananglitan madat-ugan or ma-ipit sa bug-at na materyales. Puno ra ba kaayo na og balay diha,” Berador said.

Lahug barangay captain Mary Ann delos Santos in an interview over dyAB said that all they can do as of the moment is to keep a tight watch of the area because they could not provide an evacuation center yet.

Cebu City Mayor-elect Michael Rama said that he wants to receive a formal communication from the MGB-7 regarding their findings so they would have a basis on the actions to be undertaken for the residents.

Rama said that if evacuation is necessary because of imminent danger, the city will order for it and will take care of the constituents.

For the meantime, MGB-7 also recommended for the construction of drainage canals in such a way that surface water or rainwater will be diverted away from the identified tunnel sites.

“The onset of the rainy season may result to excess surface water entering the cavity and possibly triggers further landslide.”

For a long-term solution, MGB-7 recommended for tunnels to be filled to stabilize the ground surface. (THE FREEMAN)