“Floods are acts of God, but flood losses are largely acts of man” – Gilbert F. White
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The Philippines has only two pronounced seasons: the wet season and the dry season. During the wet season, it rains aplenty. This happens from June to the early part of October.
During the rainy season, typhoons and floods are common, according to the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA), which monitors and manages the country’s weather. It is a line agency of the Department of Science and Technology (DOST).
“Floods are due to the complex combination of weather, climatic and human activities,” explained Rosalie C. Pagulayan, weather specialist with the weather bureau. “Most floods occur as a result of moderate-to-large-scale rainfall events.”
Aside from typhoons and incessant rains, there are also artificial causes of flooding. Blasting and construction of temporary dams are examples. Blasting causes landslides in the slopes of hills and mountains which may result in the unintentional damming of rivers and streams.
Construction of temporary dams, on the other hand, produces an impediment to the flow of a river or stream which then results in an overflow. Accidents like the breaking of a dike result in the entry of an enormous quantity of water in a protected area.
Denudation of forest and watershed areas may have the same effect. “Altering the ecological system in a river basin will have an impact on the hydrology of the catchment,” the weather bureau said in its website.
The country’s weather bureau says there are two types of floods: minor (usually shallow and there may not be a perceptible flow) and major. As flooding is relatively deep in most parts of the stricken areas, major flooding causes foremost destruction.
While floods take some time, usually from 12 to 24 hours or even longer, to develop after the occurrence of intense rainfall, there is a particular type which develops after no more than six hours and, frequently, after an even less time. These are what are known as flash floods.
Since floods are common throughout the country during the rainy season, the weather bureau has launched the Flood Early Warning System (FEWS) capacities. It has five basic elements: prediction, detection, communication, decision-making, and mobilization.
“In any disaster of a given magnitude, the first line of defense is still awareness of the communities at risk,” reminded Pagulayan.
Meanwhile, the Davao-based Interfacing Development Interventions for Sustainability (IDIS) urged for urgent action on worsening flooding and those ineffective flood control projects.
“As an organization championing sustainable transformation, (we express) deep concern over the worsening flooding experienced in Davao City and across the Philippines,” IDIS said in a statement. “The recent floods that submerged key urban areas once again exposed the vulnerability of our cities and the inadequacy of flood control measures meant to protect lives, livelihoods, and infrastructure.”
The IDIS research revealed a significant trend with national implications: numerous flood-prone regions within the city were previously wetlands, tidal marshes, swamps, and natural catchment areas. Years of unregulated urban expansion have reclaimed, transformed, and modified these ecosystems, leading to an alarming 95% reduction in wetlands since 1945 in Davao City.
“With rising sea levels and more intense rainfall due to climate change, waterways can no longer properly drain during high tides, causing floodwaters to spill into streets, homes, and establishments,” IDIS said.
This predicament in the city mirrors a broader issue on a national scale. In spite of the allocation of billions of pesos each year for flood control initiatives through local, regional, and congressional funding, the severity of flooding continues to escalate in various cities and provinces. This situation prompts critical inquiries regarding the efficacy, transparency, and accountability of flood control efforts throughout the country.
IDIS urged the government agencies, particularly the Department of Public Works and Highways (DPWH), local governments, and legislators to do the following:
· Provide full public disclosure on the status and effectiveness of flood control projects
funded across the country.
· Go beyond short-term, “grey” infrastructure solutions that often displace flooding rather than solve it.
· Prioritize nature-based solutions such as watershed protection, construction of retention and detention ponds, mangrove rehabilitation, and the restoration of wetlands and estuarine marshes. These solutions offer long-term, climate-resilient protection
against flooding.
“The worsening floods in Davao City are not an isolated event—they are a warning signal of what is happening and will continue to happen nationwide if business-as-usual approaches persist,” IDIS said. “Flooding is not just a local inconvenience; it is a national climate emergency that demands decisive, coordinated, and science-based action from all levels of government.
“Only by combining transparent governance with sustainable, nature-based strategies can we safeguard communities across the Philippines from the escalating threats of climate change.”
