Luzon Dams Release Water Amid Southwest Monsoon Warnings

On July 27, 2025, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) reported that four dams in Luzon opened their gates to release water as part of precautionary measures amid continuous rainfall brought by the Southwest Monsoon. These operational adjustments were essential to manage water levels and mitigate potential flood risks in the region.

According to PAGASA's data, Ipo Dam, located in Norzagaray, Bulacan, had one gate opened at a height of 0.15 meters, discharging water at a rate of 33 cubic meters per second (cms). As of 8 a.m. on Sunday, the reservoir water level (RWL) at Ipo Dam was recorded at 100.41 meters, nearing its 101.10-meter spilling threshold.

In Benguet, Ambuklao Dam had two gates open at a height of 1.0 meters, with a discharge rate of 191.20 cms. The dam's RWL stood at 751.24 meters, close to its normal high water level (NHWL) of 752 meters. Similarly, Binga Dam, also in Benguet, opened two gates at 1.0 meters, discharging 211.51 cms, while its RWL was at 574.10 meters, approaching the 575-meter NHWL.

Magat Dam, which straddles Isabela and Ifugao provinces, had the most significant activity, with two gates opened at 3.0 meters, resulting in a discharge of 656.39 cms. The dam’s RWL was measured at 185.84 meters, just a few meters below its NHWL of 190 meters.

PAGASA warned that the Southwest Monsoon would persist, bringing rains to various parts of the country, particularly affecting Ilocos Sur, La Union, Pangasinan, Zambales, Bataan, and Occidental Mindoro, where occasional rains could lead to flooding and landslides. The forecast also indicated that Metro Manila, alongside other regions including the Cordillera Administrative Region, Cagayan Valley, and CALABARZON, should prepare for cloudy skies with scattered rains and thunderstorms.

Dr. Maria Santos, a climatologist at the University of the Philippines, emphasized the importance of such precautionary measures. "Opening dam gates helps manage water levels and reduces the risk of overflow, particularly during heavy rainfall events," she explained in a recent interview.

The situation underscores the ongoing challenges posed by seasonal monsoons in the Philippines, an archipelago vulnerable to climate-induced weather events. With infrastructure and emergency preparedness strategies under constant evaluation, PAGASA and local government units remain proactive in ensuring public safety during such weather patterns.

As the rainy season continues, authorities will monitor dam levels closely and issue advisories to the public as necessary to prevent potential disasters. The proactive management of dam operations is vital in safeguarding communities across Luzon from the impacts of severe weather and climate variability.