The Angat Dam spillway, August 1, 2026. Gigie Cruz, ABS-CBN News
MANILA — The Angat watershed is now saturated and subsequent rainfall from tropical depression Luis and the southwest monsoon or Habagat could lead to further increase in the reservoir, PAGASA hydrologists said Monday.
“Based sa aming analysis, possible na baka yung watershed ng Angat is saturated na. Kung ano man ‘yung rainfall na ma-receive is madali ‘yung magiging reaction or translation nya dito sa storage ng tubig sa dam,” hydrologist Jofren Habaluyas said in a press conference.
(Based on our analysis, it is possible that the Angat watershed is already saturated. Any further rainfall in the area could immediately translate to an increase in the reservoir water level.)
As of 8 a.m. Monday, the reservoir’s water level stood at 155.41 meters, down by 4 centimeters from the previous day.
From July 29 through August 2, Angat Dam’s water level had a cumulative increase of 4.6 meters from the rains dumped by thunderstorms and a low pressure area that crossed southern Luzon.
Habaluyas said that the watershed needs about 470 millimeters of rainfall for the reservoir to reach its rule curve elevation, or normal operating level, of 180.34 meters.
Angat Dam’s normal high level is 210 meters.
“Malakas din ang possibility na aangat pa further ‘yung elevation ng Angat Dam. Pero… huwag pa ring tayong magpaka-kampante na tuluy-tuloy ang pagtaas nito dahil… it’s still below the rule curve,” Hydrometeorology Division Chief Socrates Paat said.
(There is also a high possibility that Angat Dam’s water level will continue to rise further. However, we should not be complacent because the reservoir remains below its rule curve level.)
He urged the public to continue observing water conservation measures.
“Patuloy tayong magtipid sa tupid para itong mga nababawi nating increase in water level ay hindi mabilis ang pag-deplete,” Paat added.
(Let us continue conserving water so whatever increase we gain in the reservoir will not be easily depleted.)
Angat Dam is still recovering from its all-time low record of 150.60 meters on July 25.
Praying for rain: Dumagats lament changing climate as Angat Dam hits historic low
PAGASA hydrologists earlier said that the reservoir typically begins recovering in July, with full recovery usually happening during the northeast monsoon or Amihan season.
They warned that if Angat Dam fails to reach 210 meters by the end of the year amid the prevailing El Niño, Metro Manila could face water shortages next year.
Meanwhile, other major dams in Luzon also recorded an increase in their water levels. Magat Dam rose by 1.09 meters while Pantanbangan Dam increased by 0.74 meters.
WET WEATHER TO PERSIST
Moderate to heavy rainfall continues to affect northern and Central Luzon due to tropical depression Luis, with heavy rainfall warnings in effect over parts of Pangasinan and Central Luzon.
Although the storm’s center remains east of Luzon, its thickest rain clouds are concentrated on the western side.
“‘Yung lokasyon ng makakapal na kaulapan ay nasa kanlurang bahagi [ng Luzon]. Dala iyan ng epekto nitong pagsagi… ng northwestward na hangin galing [sa] Bagyong Luis dito tumatama sa coastline… kaya mostly yung makakapal na kaulapan ay nandito,” weather forecaster Charmaine Varilla said.
(The thick rain clouds are concentrated over the western side of Luzon due to the interaction of tropical depression Luis’ northwesterly winds with the coastline.)
More areas in N. Luzon placed under wind signal as Luis stays stationary
Luis is expected to move erratically and may pass close to or make landfall over the Cagayan-Isabela area on Monday evening or early Tuesday morning.
“Nakikitaan na [ng] recurving scenario… dahil sa impluwensya at interaction nito sa… tropical cyclone Dolphin sa labas ng PAR. Inaasahan na pagsapit ng Miyerkules ay possible na humina at maging isang low pressure area o maging parte ng trough ng Bagyong Dolphin at maging parte ng [sirkulasyon] nito,” Varilla explained.
(There will be a recurving scenario due to the influence of and interaction of the storm with tropical cyclone Dolphin outside the Philippine area of responsibility. By Wednesday, Luis may weaken into a low pressure area and eventually become part of Dolphin's trough or circulation.)
Even after Luis dissipates, Dolphin-enhanced Habagat is expected to continue bringing rains over the western sections of Luzon and Visayas through the weekend.
For more weather updates, visit the ABS-CBN Calamity Hub.