Urban Flooding in Manila: Future Situation without Mitigation Measures vs Current Situation

  • City: Manila, Philippines
  • Inundation modeling area: Pasig-Marikina-San Juan River system covering about 401 km2
  • Ondoy flood event of 2009, with an approximate 100 years return period, was considered for comparing future flood risk under climate change and urban expansion.
  • Without mitigation measures, an increase of 26% was observed in areas with flood depths greater than 0.5 m.
  • Structural flood control measures, such as river flow capacity improvement, improved diversion channel regulation and dam construction were found to be highly effective in reducing the flood inundation.

Flood hazard legend