Rainfall gauges recorded about 22.2 millimeters of rain in Cebu City and Mandaue between 1 p.m. and 3 p.m. on July 30, 2026, while the Mactan gauge recorded about 9 mm.
Mayor Nestor Archival stated that around 70 percent of 104 flood-control projects implemented by the DPWH in Cebu have been completed, but their impact on flooding has been very limited.
Following the July 30 flooding, the city deployed around 400 personnel to clear clogged waterways in Barangays Tisa and Labangon, and is considering a one-hectare property nearby as a stormwater reservoir.
IT CAN take only a few hours of heavy rain for major roads in Cebu City to disappear under floodwaters, stranding motorists, shutting down businesses and trapping residents in their homes.
The flooding on July 30, 2026, was a stark example.
Rainfall gauges recorded about 22.2 millimeters of rain in Cebu City and Mandaue between 1 p.m. and 3 p.m., while the Mactan gauge recorded about 9 mm. Cebu City Disaster Risk Reduction and Management Office chairman Councilor Dave Tumulak said the rainfall was equivalent to about nine Olympic-sized swimming pools.
But the bigger question is not only how much rain fell.
It is why Cebu City’s drainage system becomes overwhelmed so quickly.
According to city officials and engineers, the answer lies in a combination of limited drainage capacity, clogged waterways, high tide, rapid urbanization and limited space to temporarily store stormwater.
Cebu’s geography
Maria Nenita Jumao-as, hydrologist and executive director of the University of San Carlos Water Resource Center, said Cebu’s narrow shape and steep terrain allow rainwater to move quickly from upland areas toward coastal communities.
Unlike wider areas with large river basins that can temporarily absorb runoff, Cebu’s geography leaves little space for water to accumulate safely.
Cebu’s geology once provided some natural protection. Much of Metro Cebu’s coastal area sits on porous Carcar limestone, allowing water to seep underground and replenish groundwater.
However, as development replaces natural surfaces with roads and buildings, less rainwater is absorbed and more flows directly into drainage systems.
The City Government is now revisiting its flood-control strategy, including the 2017 Drainage Master Plan, to determine whether existing solutions match current conditions.
A drainage system can only carry so much water
Storm drains are designed to move water away from roads and communities. They are not reservoirs.
When rainfall produces more runoff than the drainage network can handle, water begins accumulating on streets. The problem worsens when canals and drains are blocked by garbage, silt and debris.
Mayor Nestor Archival has acknowledged that many drainage structures were built decades ago, when Cebu City had fewer buildings, roads and residents.
As urbanization expanded, more land was covered by concrete, reducing the soil’s ability to absorb rainfall. More water now enters drainage systems, many of which were not designed for today’s conditions.
Archival has ordered a review of the 2017 Drainage Master Plan prepared by the Department of Public Works and Highways (DPWH), raising questions on which projects were implemented and whether they addressed the city’s most critical flood points.
Are flood-control projects solving the right problem
Around 70 percent of 104 flood-control projects implemented by the DPWH in Cebu have been completed, according to Archival.
However, the mayor said their impact on flooding has been limited.
“Maybe nakatabang, but for me, gamay ra kaayo’g tabang,” he said.
(Maybe it helped, but for me, it was very little help.)
Archival said some projects focused mainly on riverbank protection rather than increasing the city’s ability to move stormwater through its drainage network.
Flood-control structures can reduce erosion and protect communities along waterways, but they do not automatically solve drainage bottlenecks.
City officials are reviewing whether existing investments address the actual causes of flooding.
Blocked waterways reduce capacity
Garbage and accumulated silt can further reduce the amount of water drainage channels can carry.
Following the July 30 flooding, the city deployed around 400 personnel to clear waterways in Barangays Tisa and Labangon.
“When we arrived, the water was no longer flowing because garbage had clogged the waterways,” Archival said.
After debris was removed, officials said water began moving again.
The Department of Engineering and Public Works highlights the scale of the maintenance problem.
But they also raise another question: How much capacity is lost when waterways clog, and how quickly do they become blocked again?
High tide slows water release
Removing garbage, however, cannot solve every flooding problem.
Stormwater eventually has to flow into rivers and the sea. During high tide, elevated coastal water levels can slow the release of rainwater from drainage systems.
This creates a backwater effect, where water movement becomes restricted and flooding can persist even after rainfall stops.
For a coastal city like Cebu, flood management must consider not only drainage channels but also river systems and the condition of coastal discharge points.
Development increases runoff
Urban development has also changed how rainwater moves.
Before an area is developed, soil and vegetation absorb rainfall. After roads, buildings and other hard surfaces are added, more water becomes surface runoff and reaches drainage infrastructure faster.
This is why the city is inspecting mountain developments to determine whether they have adequate catchment facilities.
Archival said developers without sufficient stormwater controls may be required to add facilities if investigations show their projects contribute to flooding.
Detention ponds and catchment systems are intended to temporarily hold water and reduce the amount reaching downstream communities at once.
Proposed reservoir near Tisa-Labangon area
One proposed long-term measure is the acquisition of a one-hectare property near the Tisa-Labangon area that could serve as a stormwater reservoir.
Archival said the facility could temporarily store excess water from upland communities before releasing it gradually after heavy rainfall.
However, the flood-control value of the proposed reservoir would depend on its actual storage capacity, depth, design and ability to manage incoming water.
The City still has to determine whether the facility can hold a significant portion of runoff generated during major rainfall events.
Is land subsidence a factor?
Land subsidence, or the gradual sinking of the ground, can worsen flooding in some cities.
Cebu City, however, has not identified subsidence as a primary cause of recent floods.
Officials have instead pointed to clogged waterways, silt buildup, aging drainage infrastructure, rapid urbanization and inadequate stormwater storage as the main contributors.
Determining whether subsidence plays a role would require scientific elevation and ground-movement data.
The unfinished work
The City has created a River Desilting and Clean-up Task Force to remove obstructions, clear waterways and address structures built along river easements.
Councilor Harry Eran has also proposed measures calling for intensified declogging and dredging, drainage upgrades, stronger enforcement against illegal dumping and a 30-day flood mitigation action plan.
But cleanup alone will not solve the problem.
Cebu City already has a drainage master plan, and dozens of flood-control projects have been completed.
The bigger question is whether these measures were designed for the rainfall patterns, runoff volumes and urban conditions Cebu City faces today.
Move the water, store it or keep it out
Cebu City’s flooding problem ultimately depends on what happens to rainwater after it reaches the ground.
The City can move more water by upgrading drainage network.
It can store more water through reservoirs, detention ponds and retention facilities.
And it can reduce runoff through better land-use planning, catchment systems and protection of areas that can still absorb rainfall.
No single solution will be enough.
The July 30 flooding showed how quickly Cebu City’s system can be overwhelmed. The response now underway — from clearing canals and desilting rivers to reviewing drainage plans and exploring retention facilities — will determine whether the city is merely reacting to floods or addressing the conditions that create them.