La Mesa Dam overflows as habagat threatens more rain

Residents wade through floodwaters along Zapote Junction in Las Piñas on Saturday morning, Aug. 28, 2026 as the flooded road remains closed to vehicles.

The STAR / Edd Gumban

MANILA, Philippines — La Mesa Dam overflowed early Sunday, August 30, sending excess water toward the Tullahan River as the southwest monsoon continued to bring rain over Metro Manila and large parts of Luzon.

State weather bureau PAGASA recorded the dam's water level at 80.30 meters as of 5 a.m., above its 80.15-meter overflow elevation.

Excess water from the reservoir will flow directly into the Tullahan River, potentially affecting low-lying communities in Quezon City, Caloocan, Valenzuela, Malabon and Navotas, PAGASA said.

In Quezon City, areas identified by PAGASA include Fairview, Forest Hills Subdivision, Quirino Highway, Sta. Quiteria and San Bartolome. In Valenzuela, the advisory identified areas along the North Expressway and La Huerta Subdivision.

PAGASA warned that continued rainfall could further raise the river's water level.

The weather bureau is also monitoring a low-pressure area located 1,340 kilometers east of extreme Northern Luzon as of 3 a.m. The southwest monsoon, meanwhile, is affecting Luzon and the Visayas.

More rain, flood risk

Metro Manila may experience moderate to occasionally heavy rain over the next 12 hours, with all rivers and streams in the capital likely to be affected, according to PAGASA's general flood advisory issued at 6 a.m.

Heavy rain had already fallen over the Pasig-Marikina-Laguna de Bay river basin in the 12 hours ending at 5 a.m. Moderate to heavy rain was forecast through 5 p.m.

PAGASA warned that road and street flooding remained possible because of accumulated rainwater, poor or clogged drainage systems and higher tide levels, potentially making some roads impassable.

Waterways being monitored include the upper and lower Marikina River, Pasig River, San Juan River and waterways draining toward Laguna de Bay.

The Tullahan River basin, where heavy rain was also recorded overnight, may receive moderate to occasionally heavy rain through Sunday afternoon.

Flood advisories across Luzon

The flood threat extends beyond Metro Manila.

PAGASA forecast heavy to intense rain over the Ilocos Region, with rivers and tributaries in Pangasinan, Ilocos Sur, La Union and Ilocos Norte likely to be affected.

Moderate to heavy rain may affect the Cordillera Administrative Region and Central Luzon.

In the Cordilleras, waterways in Abra, Ifugao, Benguet, Kalinga, Mountain Province and Apayao remain under watch.

In Central Luzon, PAGASA identified waterways in Bataan and Zambales and all rivers and tributaries in Bulacan as likely to be affected.

CALABARZON may also receive moderate to occasionally heavy rain, with waterways in Laguna, Cavite, Rizal, Batangas and Quezon under monitoring.

Light to moderate rain is forecast over MIMAROPA and Western Visayas, where residents near waterways and low-lying or mountainous areas were also advised to remain alert for possible flash floods.

PAGASA advised residents in low-lying communities and near riverbanks and mountain slopes to take appropriate precautions and follow instructions from local disaster officials.