Image shows the La Mesa Dam reaching its spilling level on July 21, 2025 due to heavy rains attributed to the southwest monsoon or ‘habagat.’ (Screengrab via Radyo Pilipinas)
The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) on Monday afternoon announced that the La Mesa Dam overflowed as its water level hit 80.16 meters.
The overflow caused by the heavy downpour brought about by the southwest monsoon is seen to affect several communities along the Tullahan River in the Quezon City area, as well as Valenzuela and Malabon cities.
PAGASA hydrologist Rosalie Pagulayan said the dam overflowed at around 3 p.m.
“If the rains should continue, there will also be continuous overflow of the dam,” Pagulayan said in an interview over DZMM.
The hydrologist said La Mesa Dam’s water storage is not designed to hold a huge capacity of water, as it does not have a flood control component.
“The La Mesa Dam will overflow in the event that the dam water level reaches 80.15 m,” PAGASA earlier said.
“All residents living in the aforementioned areas and nearby areas, especially those near the river banks, are still advised to be alert for possible flooding,” it added.
Specifically, the state weather bureau warned Fairview, Forest Hills Subd., Quirino Highway, Sta. Quiteria and San Bartolome in Quezon City, North Expressway and La Huerta Subd. in Valenzuela, and Malabon.
