25 – 30 September 2009
Tropical storm Ondoy (international name, Ketsana), delivered a record 448.5 mm (17.6 inches) of rain that fell on Metro Manila between 8:00 AM and 8:00 PM local time on September 26, 2009, more than a month’s worth of average rainfall for the area and nearly double the 200-305 mm dumped by Hurricane Katrina in Louisiana in the U.S. (Knabb, et al.,2005).
The torrential rains caused a very drastic 10.99 meter rise in water level of the Marikina river and swelling of creeks all over Metro Manila. The consequent floods brought large portions of a mega city of over 11million citizens to a virtual standstill and was responsible for the 465 deaths in Metro Manila and damages amounting to PhP10.9 billion. In the 12 hours of continuous rainfall, floodwaters rose from waist level to about two storeys high in many different areas in Luzon, especially within Metro Manila. Entire streets in Antipolo, Cainta, Quezon, Makati, Malabon, Manila, Marikina, Montalban, Paranaque, Pasay, Pasig, Pateros, San Juan, San Mateo, Taguig, and Valenzuela were submerged.
Previously a community or household concern, flash floods which had merely caused inconvenience in Metro Manila resulted in a disaster of unimagined proportions in a scale constituting a national catastrophe. The attention brought by Ondoy focused future efforts to address the growing concern of worsening floods complicated by uncontrolled urbanization in the capital of the Philippines.
Knabb, R., J. Rhome, and D. Brown. (2005). “Tropical Cyclone Report: Hurricane Katrina.” December 20, updated August 10, 2006 and September 14, 2011. National Hurricane Center.
Merueñas, M. (2011). Marikina River nears ‘Ondoy’ water level. GMA News Online.
Gutro, R. (2009). Hurricanes/ Tropical cyclones. Hurricane Season 2009: Typhoon Ketsana (Western Pacific). NASA.
NDDRMC. (2009). NDRRMC Disaster Archive: Final Report on Tropical Storm Ondoy and Typhoon Pepeng.