The Agos River Cataclysmic Flooding Event
November 2004, General Nakar, Quezon
(Poster Presentation)

*Nancy R. Aguda, **Leo B. Alforte and *Jenny Anne L. Barretto
 

*Education Research Program, UP-CIDS, UP Diliman
**General Nakar Development Initiatives, Inc.

On November 29, 2004, typhoon Winnie poured record-high rains of 342 mm in just 6 hours over an already saturated Agos River drainage system, triggering a cataclysmic flooding event which obliterated entire communities in the municipalities of Real, Infanta, and General Nakar, Quezon Province. General Nakar is the worst hit since most of its barangays are situated along the Agos River. More than 90% of its total land area is sloping prompting most residents to settle either in floodplains or in the delta (Kabilogan Cluster) making them highly vulnerable to this type of geohazard.

Logs, uprooted trees, boulders and mud brought down by landslides constitute most of the stream’s load. Findings of concerned government agencies show that accumulation of logs formed artificial dams along the upstream portions of the Agos River and at the Infanta-General Nakar Bridge. The eventual failure of these artificial dams caused flashfloods which claimed a significant number of lives, washed out farmlands and destroyed major infrastructures.

Government agencies with geology-related mandates and volunteer geologists helped the community in its relief and rehabilitation efforts by mapping out geohazard prone areas, identifying safe relocation sites and conducting appropriate geohazard information campaign.