DAVAO City-based environmental group Interfacing Development Interventions for Sustainability (IDIS) warned about the urgent need to address the quickly disappearing wetlands, which contributed to the worsening flooding in the city.
In a statement, IDIS attributed the city’s worsening flood problem to decades of unchecked urban development that wiped out nearly all of its natural wetlands.
“IDIS calls on the city government to move beyond pilot initiatives and fully integrate Nature-based Solutions into its core planning processes, including the Comprehensive Land Use Plan and future flood management programs,” the group stressed.
IDIS cited historical land-use data from old Spanish- and American-era maps that show that Davao City was settled in an area with a large network of riverine and estuarine wetlands connected by creeks and waterways.
These wetlands were concentrated in areas that now make up the city’s Central Business District, including Poblacion, Agdao, Cabaguio, Matina, and Talomo.
“Decades of unsustainable urban development have reclaimed, converted, and altered these ecosystems, resulting in a staggering 95% loss of wetlands in Davao City since 1945,” IDIS stressed.
Of this percentage, high-density residential development accounted for 51.6% of urbanization.
IDIS said the loss of wetlands has affected specific cases, showing the consequences of this loss.
The group cited Laverna, near Davao International Airport, which is a wetland formed by blocked floodwaters and altered drainage and creekways, where settlements and commercial establishments were later built directly within it.
It added that Bajada (J.P. Laurel Avenue) was once a large wetland fed by a creek, but was converted into a series of linear drainage canals.
Additionally, the developments in Matina (Aplaya, Crossing, and Pangi), was established in once natural catch basins, have left rainwater pooling on the surface instead of seeping into the ground, resulting in recurring floods that have affected hundreds of families.
The organization pushed back against the notion that flooding in the city is not a serious problem simply because floodwaters recede quickly, noting this view “misses the bigger picture.”
IDIS said many flood-prone streets and barangays today were once areas that never flooded, when wetlands, creeks, and natural ground cover gave rainwater somewhere to go before reaching the roads.
“When those same areas flood today, even briefly, it is a sign that the land’s natural drainage function has been lost, not proof that the situation is manageable,” it said.
The group said that if left unaddressed, these “quick draining” floods tend to grow more frequent, more intense, and slower to recede over time, “as remaining green cover and absorptive land continue to shrink.”
While IDIS recognized engineered drainage systems as well-built, these were never designed to hold the same volume of water that the city’s natural wetlands and marshlands once did.
The group stressed that this explains why, even in areas where infrastructure has been improved, flooding continues to persist.
IDIS is pushing for the adoption of Nature-based Solutions (NbS), which the group described as a more cost-effective and sustainable alternative that works with the city’s natural terrain instead of against it.
These include developing more public green spaces that can double as flood-absorbing parks and recreational areas and preserving and rehabilitating the city’s remaining wetland fragments alongside watershed protection and mangrove rehabilitation.
The group added that the city should strictly enforce City Ordinance No. 0298-09, or the Davao City Rainwater Ordinance of 2009, which mandates rainwater harvesting, storage, and utilization citywide.
Residents are also urged to do their part by installing rainwater catchment systems, using permeable surfaces, and planting native vegetation to help reduce stormwater runoff.
“Lasting resilience cannot be achieved by the government alone,” IDIS said, adding that it requires the collective action of communities that recognize nature as an ally rather than an obstacle to development.
“As climate impacts continue to intensify, Davao City’s future depends on choosing to work with nature, not against it,” the group stressed.
