Cebu City littered with 770 sinkholes

CEBU, Philippines - While authorities assure there is no reason to panic, the Cebu City Disaster Risk Reduction Office yesterday said the Mines and Geo-sciences Bureau has discovered that there are least 770 sinkholes in the urban barangays of the city.

A few of them are even near establishments.

But CCDRRMO head Nagiel Bañacia said MGB told them that there was nothing to worry about since engineering mitigation for sinkholes had been adopted, including the strengthening of structures near sinkholes.

He said that a recent MGB survey showed that the city’s soil is composed mostly of limestone and is therefore vulnerable to the formation of sinkholes.

A sinkhole is caused by water erosion that provides a route for surface water to disappear underground.

It is formed by water from rainfall that absorbs carbon dioxide, making the water acidic, which results to the formation of voids and cavities. When the cavities continue to grow they weaken the overlying materials around and a sinkhole would form.

“It’s hard to explain for this are engineering matters. Basta one thing I am sure is strengthening the building design (has been resorted to),” he said.

He said MGB was careful in disclosing the result of its recent survey since they do not want to cause panic among the public. This, Bañacia said, was because people immediately think of a portion of a land collapsing, leaving a deep gaping hole, when they hear the word “sinkhole.”

In fact, he said, CCDRRMO invited MGB to talk about the discovered sinkholes in the city before members of the City Council next month or in September to explain it to legislators.

Bañacia said the city government is thankful that MGB conducted such study as the data it culled would help CCDRRMO in its development plans, particularly as inputs for the city engineers.

Sinkholes have already been noted in the past in some parts of the country like in Bilar, Bohol; La Libertad, Negros Oriental; Panganan Island, Bohol; and among others.

Meanwhile on the slumping of the soil in the mountain Barangay of Sirao, Bañacia said they proposed the allocation of P3 million for the displaced residents who would not be allowed to return to their homes due to the danger caused by the moving soil. The amount is due for final deliberation at the City Council.

MGB has noted that with Sirao being among the landslide-prone areas of the city, there is always soil movement there every now and then. It also said that the barangay has an underground river, which contributed greatly to the continuing land movement.

“Kung dunay uwan kinahanglan wala na gyuy mga tawo ngadto kay mag sige  man ang lihok sa yuta, ilabina karon naay earthquake gahapon (Thursday).Wa ta kahibawo nairog na sad ang yuta didto,” he said.

He said the government cannot do anything about the soil movement, which was why MGB recommended that the area should be vacated for the safety of the residents.

Bañacia said the city’s Division for the Welfare of the Urban Poor had already identified a safe place where the affected residents can build permanent structures for their homes in a city-owned property in Barangay Guba.

Majority of the displaced residents are currently staying with their respective relatives in neighboring barangays.

“Ang uban moanha lang sa Sirao kay naa man ilahang panginabuhian pero inig gabii na adto sila matulog sa ilahang mga kaliwat,” Bañacia said.

Despite this, a staff member of his office regularly monitors the area to ensure no one stays behind.

DWUP is currently revalidating the number of affected families, which currently stood at 42 families, for the final list of beneficiaries of City Hall assistance. (FREEMAN)