Blocked Tullahan river behind Metro Manila floods, says RSA

San Miguel Corporation (SMC) President and CEO Ramon S. Ang said Friday, August 8, that aerial inspections revealed a much deeper cause behind Metro Manila’s persistent flooding—a massive obstruction along the Tullahan River, the region’s main drainage outlet.

Speaking alongside MMDA Chairman Romando Artes and Metro Manila mayors, Ang dismissed claims that the MRT-7 construction was to blame for the recent flooding in the region.

He recounted receiving a call from First Lady Liza Araneta-Marcos inquiring about the cause of severe floods in Quezon City. “Ramon, bakit nagkaganun?” he quoted her asking. Ang said he immediately mobilized his teams—with drones in tow—to inspect critical drainage systems, particularly along Commonwealth Avenue.

The investigation initially found that the local drainage system had a clogged 12-inch pipe, which was quickly cleaned. But when floodwaters still failed to drain efficiently, Ang ordered a more extensive inspection using helicopters.

What they found, he said, was alarming: a portion of the Tullahan River—spanning over a kilometer—had been completely blocked and built over with roads, informal housing, and even a school.

“Hindi 10 meters, more than 1 kilometer ang tinakpan,” Ang emphasized, adding that this stretch of river is a critical outlet for floodwaters from La Mesa Dam.

“Pag may bagyo, nagre-release ng tubig [ang dam], isa lang ho ang labasan niyan—papunta ng Manila Bay, sa Tullahan River,” he explained. The blockage, he said, has essentially crippled the entire drainage capacity of Quezon City, Valenzuela, Navotas, Malabon, and Obando.

Ang criticized suggestions that road-based water storage solutions—like those allegedly used in Bonifacio Global City (BGC)—could solve flooding elsewhere in the capital.

“Kalokohan ’yon,” he said bluntly, adding that BGC’s flood resilience is more likely due to its elevation and natural sinkholes from nearby fault lines, not any engineered water catchment under its roads.

Asserting that flooding is a direct result of blocked waterways, Ang offered a sweeping but clear solution: remove illegal structures and reopen the natural paths of Metro Manila’s rivers.

“Tanggalin ang mga kalsada, housing, eskwela sa ibabaw ng ilog. Solved na ang baha ng buong Metro Manila,” he said. He credited the MMDA under Chairman Artes for understanding the problem deeply and working with his team in addressing it.

Ang further announced that San Miguel Corporation will lead flood mitigation efforts in Metro Manila—at no cost to the government or the public.

He committed to purchasing land to relocate affected residents and even schools currently sitting atop waterways. “Tatayo ako ng kapalit na eskwela. Pati housing, bibili na ako ng lupa para tayuan ng pabahay ng mga tao doon,” he said.

This is not the first time SMC has taken such action. Ang recalled how SMC absorbed the full cost of replacing damaged drainage infrastructure in Bicutan and the SLEX area last year, after floods were wrongly blamed on their operations.

“Kapag may problema, huwag kayo magturuan,” he said “Hanapin natin ang problema, imbestigahan natin. Kami, gumawa kami ng solusyon.”