THE PROPOSED underground rainwater detention facility beneath the University of Santo Tomas’ Open Field is intended to temporarily store excess rainwater and release it gradually into the drainage system. The Metropolitan Manila Development Authority has proposed a facility with a capacity of about 72,000 cubic meters, arguing that it could hold roughly twice the estimated flood volume along España Boulevard during a major downpour.
A detention basin can, in principle, serve a legitimate purpose. Underground storage is already used elsewhere as one component of flood mitigation. The problem is not necessarily the idea of temporarily storing water. The problem is treating storage as though it addresses the larger system that caused the water to accumulate in the first place.
The government’s own statements make this clear.
In August, DPWH Secretary Vince Dizon said España Boulevard’s drainage system is decades old and needs to be enlarged. He also acknowledged that one of the problems in España is that there is “no outlet” for the water once the existing drainage system fills up. The government plans to construct four cross-drainages to carry water toward Manila’s esteros and eventually the Pasig River, while larger drainage improvements are being lined up in the 2027 budget.
That raises a basic question: if the water has nowhere to go, how much does it really solve to simply give it another place to sit?
The flooding around UST is not an isolated phenomenon. Historical accounts of Manila’s waterways show that Sampaloc was once a swampy area where water flowing from higher areas of what are now Santa Mesa and parts of Quezon City was drained by creeks and esteros, including waterways near UST and FEU. Many of these waterways were eventually buried as Manila urbanized. The upstream branches of the Estero de San Miguel, which once drained the UST campus and portions of Sampaloc, have also disappeared.
So, yes, the UST–España area has a historical relationship with water. But the lesson from that history should not simply be to dig another hole.
It should be to understand where the water comes from, where it naturally used to flow, where it is supposed to go now, and why the existing system fails to carry it there.
That distinction matters because Metro Manila’s flooding does not respect political boundaries. Water moving through Manila is connected to a much larger network of rivers, tributaries, drainage channels, and pumping stations. Quezon City, for instance, has developed a city-wide Drainage Master Plan that accounts for its 44 tributaries, five major river systems, and existing man-made drainage networks.
The government itself has recognized that flood mitigation requires more than one intervention. The MMDA has been upgrading pumping stations across Metro Manila, while other proposed projects include additional detention and impounding facilities. The national government has likewise said flood management projects must be appropriate to the conditions of each area rather than treated as a single solution for the entire metropolis.
This is why the UST proposal deserves scrutiny beyond the question of whether a 72,000-cubic-meter basin can hold floodwater.
The UST Open Field is not an empty lot waiting to be excavated. UST identifies its open field as one of Manila’s biggest open green spaces and a historical landmark that has hosted major University events and even a papal appearance. The Grandstand and Open Spaces were declared a National Cultural Treasure in 2010.
Any construction beneath it, therefore, is not merely an issue of cost and construction. It involves a heritage site far older than most of the people who might consider potentially ruining it, an existing green space—arguably one of the last remaining open areas—and a cultural heritage designed to outlive any obstacle the country faces.
And there is already evidence that the University has invested in addressing its own drainage limitations. UST completed a stormwater drainage improvement project designed to replace existing drainage lines and provide detention facilities within its 21.5-hectare campus.
The question, then, should not be whether Manila can find another place to put its floodwater.
It should be whether Manila is fixing the system that keeps putting communities underwater in the first place.
Pressuring UST to surrender its historic grounds—a National Cultural Treasure declared by the state itself—to serve as a catchbasin is merely an attempt to evade accountability for decades of poor planning, corrupt lawmakers, and “ghost” flood control projects tied to DPWH contractors.
Digging under UST offers a reductionist distraction rather than a genuine solution. Manila needs no more performative stopgaps; it demands real, honest, and comprehensive infrastructure that targets the root of the crisis.
