Street floods in Metro Manila and possible solutions

Area of Science:

• Urban hydrology and flood risk assessment.

Background:

• Urban floods from thunderstorms significantly disrupt road traffic in Metro Manila.
• Traffic congestion due to flooding incurs substantial economic losses, estimated at 2.4 billion pesos daily by the Japan International Cooperation Agency (JICA).

Purpose of the Study:

• To identify the primary causes of surface flooding in Metro Manila.
• To propose viable solutions for mitigating traffic disruptions caused by urban floods.

Main Methods:

• Utilized Light Detection and Ranging (LiDAR)-derived topography for detailed terrain analysis.
• Conducted flood simulations to model inundation patterns.
• Incorporated anecdotal reports to validate findings and understand real-world impacts.

Main Results:

• Flood-prone areas are predominantly located at the intersection of creeks and streets within topographic lows.
• Flooding occurs when creeks overflow or when street drainage to stream channels is inadequate.
• These events lead to road inundation and paralyze traffic.

Conclusions:

• Road elevation and improved drainage infrastructure directed towards creeks are recommended solutions.
• Implementing these solutions can alleviate traffic paralysis during short-lived rain events.