An official from the Department of Environment and Natural Resources (DENR) disclosed on Friday that urbanization — not quarrying — is the main culprit in the recent flooding in Metro Manila amid the continued rains caused by severe tropical storm “Enteng” and the southwest monsoon.

DENR Undersecretary Carlos Primo David attributed the massive flooding in Metro Manila to the vast urbanized areas, adding that quarrying operations in Rizal, which many people have blamed for the flood, have only a minimal effect.

David also stressed that cemented urban areas have the same effect as a quarry in terms of flooding.

“When the area is paved, no rainwater will enter the ground. If we compare how much area is covered by quarries versus how much area is covered by cities and urbanized areas, there is no comparison at all. We’re talking about 350 hectares of quarry versus more than 20,000 hectares of urbanized area,” David said.

He added that the effect of quarrying on the massive flooding Metro Manila has experienced these past days was “very minimal at about 1 percent only.”

However, he stressed that the agency will still investigate these quarrying operations to determine their contribution to the flooding.

David said the DENR would hold a dialogue with quarry operators next week to discuss environmental issues.

“We will investigate and see and make sure that the quarry operations do not contribute to the intensified flooding in the local area,” he said.

David noted that about seven quarrying operators in Rizal cover an estimated 350 hectares of land, and none of them is in the protected 69,000-hectare Upper Marikina watershed.

“But definitely, categorically, I can say, we could not blame the quarry operations for the flooding that we are experiencing here in Metro Manila,” David said.

Meanwhile, David also said the department is eyeing rehabilitating the old Wawa Dam in Rodriguez, Rizal, which could help mitigate flooding in Rizal and Metro Manila.

“One potential project that we wish to do is the old Wawa Dam. If you remember, the Wawa Dam seemed like a waterfall,” he said.

“It is a dam that is no longer functioning. It does not store water because it just flows continuously. You can raise it a little, like one or two meters, so that when a big storm comes, you drain it to make more room. That will become an impoundment and reduce flooding downstream.”

At the same time, he said, it could serve as another source of water supply for Metro Manila residents.

To recall, President Ferdinand R. Marcos Jr. on Wednesday conducted an aerial inspection of flood-hit areas in the cities of Marikina and Antipolo after the onslaught of “Enteng.”