Deluge in Quezon City: 7 days of rainfall in an hour
Outdated drainage systems caused many parts of Quezon City, including elevated areas historically not prone to flooding, to be submerged in head-deep water on Saturday afternoon after more than seven days’ worth of rain poured in just an hour.
The city government said over the weekend it would strive for the “immediate and continuous improvement” of its drainage master plan (DMP), instead of flood control projects, as a solution to the perennial flooding problem.
Saturday afternoon’s torrential rainfall was extremely isolated and experienced only in the city, based on rainfall recorded in 25 other weather stations in Metro Manila and in the nearby provinces of Rizal and Bulacan.
Philippine Atmospheric, Geophysical and Astronomical Services Administration data showed 141 millimeters of rain were dumped at its Science Garden station in Quezon City from 12:01 a.m. to 11:59 p.m. on Aug. 30 due to the southwest monsoon (“habagat”).
The inclement weather peaked from 2 p.m. to 3 p.m. when 121 mm was recorded, which was equivalent to 7.4 days of rainfall.
“The city’s drainage system could not handle the massive volume of rainfall in such a short period, which resulted in severe flooding, even in some areas that do not usually experience flooding,” the Quezon City government said in a statement on Saturday evening.
More than ‘Ondoy’
Most of the flooded communities were located in District 1 (western barangays bordering Manila and southern Caloocan), District 3 (southeastern barangays bordering Marikina and Pasig), and District 4 (south central barangays bordering Manila and San Juan).
Thirty-six, or one-fourth of the city’s 142 barangays, were affected by the floods.
The city government, however, said floodwaters in most areas subsided quickly due to consistent unclogging of waterways.
‘Phenomenal’
It noted that the peak of Saturday’s deluge reached 121 mm in just one hour, which was significantly higher than the maximum 90 mm per hour rainfall recorded during Tropical Storm “Ondoy” (international name: Ketsana).
As of Sunday, 882 families or 2,941 individuals were staying in evacuation centers, it said.
Citing a preliminary analysis by the University of the Philippines Resilience Institute, the city government also described Saturday’s downpour as “phenomenal.”
Parts of the University of the Philippines Diliman campus, Apolonio Samson and Katipunan barangays experienced head-deep floods, while NIA Road in Barangay Pinyahan was submerged in neck-deep water.
Roads which were not typically flooded even on heavy downpour were also submerged. The stretch of Katipunan Avenue was inundated with knee-deep water, while Elliptical Road in the city center experienced gutter-deep flood.
“The local government will continue to push for the full implementation of the DMP as a long-term and effective solution to the city’s flooding problem, instead of flood control projects that have not undergone the review and assessment,” the city government said.
‘Wasteful’ projects
Quezon City Mayor Joy Belmonte was among the first to back President Marcos’ directive to investigate the depth of corruption in flood control projects.
In a press briefing on Friday, Belmonte said only two of 254 flood control projects implemented by the Department of Public Works and Highways (DPWH) in the city from 2021 to 2025 were able to secure a certificate of coordination, which is a requirement under a local ordinance.
In some cases, the DPWH still proceeded with the project despite clear disapproval from the local government.
Legal officer Carlo Austria said the city government is studying administrative and criminal charges against those found liable for the implementation of the projects.
Belmonte described these projects as “wasteful,” noting that many are not aligned with the city’s drainage masterplan.
“We seek accountability from those responsible for the anomalies related to the flood control projects in our city. Thus, we will cooperate in every possible way with the investigating agencies designated by the President,” she said.
Following the flooding in Metro Manila and parts of Luzon in late July, Mr. Marcos said systems that have been in place for disaster response and management no longer apply due to climate change.
He called for long term, not ad hoc, solutions to address the problem.
