The La Mesa Dam has officially begun to overflow as of 3 p.m. Monday, July 21, with its water level reaching 80.16 meters, according to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).
The overflowing dam is prompting authorities to issue a flood alert to residents living in low-lying communities along the Tullahan River. These include portions of Quezon City, Valenzuela, Caloocan, Malabon, and Navotas—areas historically vulnerable to sudden water surges and inundation.
PAGASA and local disaster risk reduction offices have urged residents to stay on high alert and prepare for possible evacuation should water levels in nearby creeks and rivers continue to rise. The continuous rains brought by the southwest monsoon, or habagat, have contributed significantly to the dam’s rapid rise.
The Metropolitan Manila Development Authority (MMDA) and local government units have already deployed emergency response teams and prepositioned rescue equipment in flood-prone barangays.
“Our rescue teams are on standby, and we are monitoring the situation round the clock,” said an official from the Quezon City Disaster Risk Reduction and Management Office.
Motorists are also advised to avoid areas near the Tullahan River due to possible road closures or traffic disruptions caused by flooding.
Authorities are encouraging residents to monitor official government channels and heed evacuation notices when issued. In the meantime, families living near waterways are urged to secure valuables and prepare emergency kits.
This marks one of the earliest overflows of the La Mesa Dam in recent years, highlighting the need for heightened preparedness as the rainy season intensifies.