DENR Cumulative Impact Assessment Warns of Reclamation Risks

Reclamation projects in Greater Metro Manila can threaten marine ecosystems, threaten livelihoods, and worsen flooding in urban centers. These were the findings of the 2024 Cumulative Impact Assessment (CIA) conducted by the Marine Environment and Resources Foundation (MERF) for the Department of Environment and Natural Resources (DENR).

What Happened?

In a press conference on April 30, DENR Secretary Maria Antonia Yulo-Loyzaga emphasized the importance of the cumulative impact assessment. This is a scientific review of the combined effects of multiple reclamation projects—past, ongoing, and proposed—on Manila Bay’s water systems, biodiversity, and nearby communities. MERF, a nonprofit research group affiliated with the UP Marine Science Institute, led the study.

Secretary Yulo-Loyzaga said these results have been forwarded to President Ferdinand Marcos and to all the agencies covered by the Supreme Court’s writ of continuing mandamus issued in 2008.

The Study

MERF assessed two ongoing, 12 approved, and seven proposed reclamation projects. A team of 48 experts—including oceanographers, ecologists, and planners—developed flood risk and water circulation models, tested water quality, and surveyed marine life across seasons. 

Their study documented 51 coral genera and 167 fish species, revealing a rich biodiversity that offers hope for future management despite the challenges.

The Findings

Dr. Charina Lyn A. Repollo, MERF’s lead researcher, then shared their findings from the cumulative impact assessment. She warned that the Manila Bay reclamation projects could do the following:

• Disrupt natural water flow and trap pollutants, especially during typhoons
• Reduce fishing grounds critical to coastal communities
• Increase sedimentation and harmful algal blooms
• Worsen flooding in low-lying areas by blocking natural drainage pathways

According to Dr. Repollo, these risks threaten not just ecosystems but also food security, public health, and urban resilience.

What’s Next?

The DENR will review Environmental Compliance Certificates (ECCs) issued to Manila Bay reclamation projects. This process will include consultations with the Philippine Reclamation Authority, local governments, and stakeholders.

“As Manila Bay is alive, local government units need to take into consideration the social impacts, the cultural, legal, and ecological considerations in their development goals,” Secretary Yulo-Loyzaga said.

READ: Addressing Metro Manila’s Water Crisis

The cumulative impact assessment highlights the need for regular water and shellfish quality monitoring to safeguard public health and fisheries. It also calls for greater accountability from project proponents. As a result, Phase 2 of the MERF CIA will develop improved monitoring systems and flood modeling.