Reclamation has often been framed as a hallmark of modernization—an ambitious undertaking to expand coastlines, stimulate commerce, and create new urban spaces. Yet the scientific record and the actual experiences of coastal communities point to a starkly different reality. Reclamation is not a deterrent to flooding. It is among its most potent drivers.

And the recent claim of the Philippine Reclamation Authority that reclamation mitigates flooding must be examined thoroughly. Unfortunately, it collapses under scientific scrutiny. Even the most fundamental physical law—the Archimedes principle—refutes such an assertion. The moment massive volumes of fill materials are dumped into coastal waters, the displaced water must move. With no additional basin to receive it, that water is forced to flow to our communities, and nowhere else. The effect is predictable: elevated water levels, intensified storm surges, and longer-lasting floods in adjacent communities.

Are these hypothetical risks? Hydrological studies in Manila Bay and similar coastal systems have documented how reclamation obstructs natural drainage. River tributaries and estuaries that once carried rainwater and floodwaters toward the sea are narrowed or sealed. As their outlets constrict, floodwaters accumulate inland, overwhelming communities during even moderate rainfall.

Compounding this is the alarming rate of land subsidence across several coastal zones in Metro Manila. Many areas are sinking due to excessive groundwater extraction. Reclamation—by adding immense structural weight—accelerates this downward movement. In effect, communities are being pushed deeper below sea level at the very moment seas are rising due to climate change. It is a dangerous convergence that no amount of coastal engineering can fully counteract.

Reclamation also inflicts irreversible harm on ecosystems that serve as natural flood defenses. Mangrove forests, coral reefs, and seagrass beds once absorbed wave energy, buffered storm surges, and stabilized coastlines. However, reclamation destroys them. These losses leave communities more exposed to flooding and simultaneously deprive fisherfolk of their primary livelihood, eroding food security and deepening poverty.

To persist in describing reclamation as a flood solution is not only scientifically unsound; it is a disservice to the vulnerable populations whose safety depends on evidence-based policymaking.

This is why the government must immediately impose a comprehensive moratorium on all ongoing and proposed reclamation projects. It must commission independent cumulative impact assessments—not studies financed by proponents—and make the findings accessible to the public.

Equally important is the restoration of natural coastal defenses. The state should prioritize mangrove rehabilitation, wetland restoration, and coral ecosystem recovery, all of which provide proven and cost-effective flood mitigation. Urban planning must shift toward climate-resilient infrastructure: modernized drainage systems, protected floodplains, and strict zoning that prohibits development in vulnerable areas.

Private enterprises must adopt a posture of environmental accountability. This includes withdrawing from reclamation ventures, investing in nature-based coastal protection, and supporting sustainable livelihood programs for affected communities. Long-term business stability depends on ecological stability—there is no economic growth on a sinking coastline.

Citizens, meanwhile, can participate by remaining vigilant, demanding transparency, and challenging misleading narratives. They can speak in public consultations, support environmental advocacy, and elect leaders committed to climate resilience and ecological protection. Collective insistence on truth and responsibility is among the most powerful tools the public possesses.

Reclamation is not the solution to flooding—it is a primary cause. If the nation is to avoid a future defined by chronic inundation and irreversible coastal loss, it must reject destructive expansion and embrace the science that points us toward true resilience.