City sits atop 770 sinkholes

Close to 800 sinkholes around the urban area of Cebu City alone have been discovered by the Mines and Geosciences Bureau (MGB) 7.

Geologists said that this is because much of the city’s soil is composed of limestone.

A sinkhole is a cavity in the ground, especially in the limestone bedrock, which is caused by water erosion. This leads to an alternative route for surface water to disappear underground.

The signs of sinkholes include the growth of ficus balete trees in the area and a catch basin where runoff water flows.

But despite this, the MGB 7 asked the public not to panic and instead adopt mitigation measures.

These include asking structural engineers to incorporate in their development plans the presence of sinkholes and for the Office of the Building Official to add this as a requirement when accessing permit applications.

In an interview yesterday, Nagiel Bañacia, chief of the City Disaster Risk Reduction Management Office, said the MGB will continue to monitor sinkholes, including in mountain barangays.

“The geologists saw the cracks in many of our infrastructures and they concluded that those are manifestations of sinkholes. We hope that by knowing that there are 770 sinkholes in the city proper alone, structural engineers can plan better how they will develop their projects,” he said.

Bañacia said the Philippine Institute of Volcanology and Seismology is also conducting a study to locate fault lines. This came after a magnitude 6.5 earthquake struck the town of Jaro, Leyte last Thursday afternoon.