It was caused by an unusual Ondoy-like rainfall event.
In a statement on Saturday, August 30, the Quezon City local government unit (LGU) reported that 36 out of its 142 barangays were affected by the flooding that was caused by heavy rains.
These villages are mostly located in Districts 1, 3, and 4, which the QC LGU caused inconvenience to the public.
It also shared that a preliminary analysis by the UP Resilience Institute and UP NOAH Center, which was based on rain gauges and weather stations in Metro Manila of the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) and IRISEUP of the city government.
According to them, what happened can be described as a “phenomenal” rainfall event, adding that most of the water were dumped over Quezon City and Nangka in nearby Marikina City.
“Umabot sa 121 millimeters sa loob lamang ng isang oras ang kasagsagan ng ulan kanina sa Quezon City, higit na mataas kaysa sa pinakamataas na lakas ng ulan sa loob ng isang oras noong panahon ng Bagyong Ondoy (~90 mm/oras),” the QC LGU explained further.
As such, the drainage system of the city was not able to cope with the intense rains within a short period of time, which resulted to flooding even in areas not usually experiencing these.
The local government assured, “Ang agaran at tuloy-tuloy na pagsasaayos ng drainage system ang sinisikap nating solusyunan base na rin sa isinasaad ng Drainage Master Plan (DMP) ng lungsod.“
Regarding the floods, these subsided pretty quickly, which the local government attributed to the persistent declogging operations all-year round of its Department of Engineering.
The Department of Sanitation and Cleanup Works had also been utilized to remove debris that may have been stuck into the waterways as a result of the flooding.
“Patuloy na isusulong ng lokal na pamahalaan na ganap na maipatupad ang nilalaman ng DMP bilang pangmatagalan at epektibong solusyon sa pagbaha sa lungsod, sa halip na flood control projects na hindi dumaan sa pagsusuri at pag-aaral ng lokal na pamahalaan,” the statement ended.
Some of the areas where floods were recorded include the G. Araneta Ave., Mo. Ignacia St., and even some portions of EDSA.