River cleanup eases flooding amid heavy rains in PH

Major rivers cleaned and maintained by San Miguel Corporation (SMC) continued to carry large volumes of stormwater during sustained rains over the past two weeks, helping mitigate flooding in surrounding areas.

SMC cleanup teams reported no major incidents of river overflow in most areas covered by the program, except along portions of the San Juan River on Aug. 17, when exceptionally heavy rainfall pushed water levels beyond critical levels.

In a news release Monday, SMC Chairman and CEO Ramon S. Ang said rivers under the company’s long-running Better Rivers PH initiative, now aligned with the government’s Oplan Kontra Baha program, were better able to handle higher volumes of rainwater because of increased carrying capacity and improved flow.

Since 2020, SMC has removed accumulated silt, waste and other obstructions from major waterways, deepened and widened critical sections, and carried out regular maintenance cleanups, at no cost to the government.

Ang said the recent rains also highlighted the difference between river flooding, which occurs when rivers overflow their banks, and localized drainage flooding, which can occur when intense rainfall overwhelms or cannot move efficiently through storm drains, canals, creeks and pipes because of blockages or inadequate drainage capacity.

The Department of Science and Technology-Philippine Atmospheric, Geophysical and Astronomical Services Administration said its Science Garden station in Quezon City recorded 201.7 millimeters of rain in just five hours on Aug. 17, including 138.7 millimeters between noon and 2 p.m.

For perspective, the five-hour total was already close to half of the 455 millimeters recorded at the same station during Tropical Storm Ondoy in September 2009, when the record rainfall fell over roughly nine hours.

The exceptionally heavy rainfall pushed the San Juan River beyond critical levels, with overflow observed near Barangays Tatalon and Talayan in Quezon City.

Farther downstream, however, no river overflow was observed in San Juan City and Mandaluyong, where SMC’s cleanup teams are nearing completion of maintenance dredging.

SMC has removed more than 442,700 metric tons of silt and waste from the San Juan River since 2022, including 322,700 tons from 2022 to 2024 and more than 120,000 tons from maintenance work that began in September 2025.

Along the Tullahan River, which runs from the La Mesa Dam through Quezon City and the CAMANAVA area before reaching Manila Bay, water levels remained below critical levels and no major river-related flooding was reported in nearby communities despite the heavy rains.

SMC has removed more than 1.3 million metric tons of silt and waste from the Tullahan River, including about 184,000 tons from ongoing maintenance work.

In Laguna, where Better Rivers PH has removed more than 775,000 metric tons of silt and waste, rivers in San Pedro, Biñan, Sta. Rosa and Cabuyao were also observed to be flowing well. No flooding was recorded on any portion of the South Luzon Expressway.

There was also no flooding at the Ninoy Aquino International Airport or in nearby communities following SMC’s cleanup of rivers and creeks around the airport in Parañaque City. The program removed more than 380,000 metric tons of silt and waste from Parañaque waterways.

Flooding still occurred in other parts of Parañaque, including upstream areas outside SMC’s cleanup coverage, although floodwaters receded as conditions improved.

In Las Piñas City, where SMC is cleaning the Zapote and Las Piñas rivers, no major river-related flooding was recorded. Nearly 210,000 metric tons of silt and waste have so far been removed from the two waterways, helping improve their flow toward Manila Bay

At G. Araneta Avenue in Quezon City, historically one of the areas affected early during heavy rains, flooding still occurred but waters receded as conditions improved. SMC said continued maintenance cleanup has helped improve the flow of the San Juan River.

Other flood-control improvements have also contributed, including the opening of wall restrictions at the Matalahib Creek Pumping Station in Talayan, new drainage pipes installed by the Department of Public Works and Highways in Tatalon, and stormwater detention basins built by the Quezon City government.

As floodwaters subsided, however, SMC teams observed significant amounts of garbage along G. Araneta Avenue. Improperly disposed waste remains a significant contributor to localized flooding because it can clog drains, creeks and smaller waterways that carry stormwater toward major rivers.

“Cleaning up our rivers is a big help in mitigating floods, but it is not enough by itself. It is part of a bigger set of solutions,” Ang said. “The whole system has to work, from our drains and creeks to pumping stations, flood-control infrastructure and the major rivers that carry the water downstream.”

“We also have a role to play. Better-flowing rivers can move floodwaters out more quickly, but water still has to reach those rivers. We need to keep garbage out of our drains and waterways,” he added.

Since 2020, SMC has undertaken one of the country’s largest privately funded river cleanup programs. Better Rivers PH was aligned last year with the government’s Oplan Kontra Baha, a broader flood-mitigation effort led by the Department of Public Works and Highways and the Metropolitan Manila Development Authority, with other national agencies, local governments and the private sector.

As of Aug. 18, Better Rivers PH has removed more than 9.387 million metric tons of silt and waste from over 204 kilometers of waterways across Metro Manila, Bulacan and Laguna. SMC recently expanded the program to the Visayas with the cleanup of the Butuanon River in Mandaue City, Cebu.

-Philippine News Agency