La Mesa Dam (Manila Bulletin File Photo)
La Mesa Dam in Quezon City overflowed at 3 p.m. on Monday, July 21, after its water reached the spilling level of 80.15 meters due to heavy rainfall brought by the southwest monsoon, or “habagat.”
The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) had issued warnings about rising water levels since Saturday, July 19.
Starting at 8 a.m. on Monday, the dam’s water level rose from 79.69 meters to 80.16 meters by 3 p.m.
Since La Mesa Dam lacks gates to control excess water, any level above 80.15 meters results in automatic overflow.
PAGASA warned that flooding may occur in low-lying areas along the Tullahan River, including parts of Quezon City (Fairview, Forest Hills Subdivision, Quirino Highway, Sta. Quiteria, and San Bartolome), Valenzuela (North Luzon Expressway, La Huerta Subdivision), and Malabon.
It urged residents in these areas and nearby communities, particularly those near riverbanks, to stay alert and prepare for possible evacuations.