The Interface Development Interventions (IDIS) has urged the Davao City Government to adopt nature-based solutions to address worsening flooding, warning that decades of wetland loss and rapid urbanization have significantly reduced the city’s natural capacity to absorb rainwater.
In a statement, the environmental group said the recent flooding in several communities should be treated as a warning of deeper environmental issues rather than a temporary inconvenience.
“Davao City has once again experienced flooding in several communities, affecting the daily lives of many Dabawenyos. While floodwaters may eventually recede, these incidents raise important questions about how we understand, manage, and respond to flooding in a rapidly developing city,” IDIS said.
The organization explained that Davao City was originally surrounded by an extensive system of wetlands, rivers, creeks, and estuaries that naturally stored rainwater and helped reduce flooding.
Citing historical land-use records from the Spanish and American periods, IDIS said these wetlands once covered areas now occupied by Poblacion, Agdao, Cabaguio, Matina, and Talomo.
However, the group said approximately 95 percent of these wetlands have disappeared since 1945 due to rapid urban expansion.
According to IDIS, high-density residential developments accounted for 51.6 percent of wetland loss, while commercial developments contributed another 33 percent.
“These wetlands once absorbed rainfall, retained surface water during monsoons, and guaranteed water supply during dry spells. Their disappearance has left many communities more vulnerable to flooding,” the group said.
IDIS pointed to several areas that were once natural wetlands but have since been converted for development. It cited Laverna near Davao International Airport, which is now occupied by residential and commercial establishments, and Bajada Avenue, which was formerly a large wetland connected by creeks before being transformed into drainage canals.
The group also identified Matina Aplaya, Matina Crossing, and Pangi as former natural catchment areas where development has reduced the land’s ability to absorb rainwater, resulting in recurring floods that have displaced hundreds of families.
IDIS also challenged the common perception that flooding in Davao City is not a major concern because floodwaters usually recede quickly.
“A common response to flooding in Davao is that it isn’t a serious problem because the water recedes quickly. This reasoning misses the bigger picture. The speed at which floodwater drains says nothing about whether an area should be flooding at all,” the organization said.
It emphasized that many flood-prone communities today were once naturally protected by wetlands, creeks, and vegetation that allowed rainwater to infiltrate the ground or flow safely before reaching populated areas.
The group added that drainage infrastructure alone cannot replace the water storage function once provided by wetlands.
“Engineered drainage systems, however well-built, were never designed to hold the same volume of water that the city’s natural wetlands and marshlands once did. Davao City paved over the very terrain that used to do this job for free and is now paying to replace it with concrete,” IDIS said.
To help reduce flood risks, IDIS called on the city government to incorporate nature-based solutions into urban planning by expanding green spaces that can temporarily store floodwater, protecting and restoring remaining wetlands, watersheds, and mangrove forests, and strictly enforcing the Davao City Rainwater Ordinance of 2009 to promote rainwater harvesting in homes and businesses.
The organization also encouraged residents to contribute to flood resilience by installing rainwater catchment systems, using permeable materials around their homes, and planting native trees and vegetation.
