FLOOD-PRONE downstream communities near Magat Dam in Isabela province must prepare for a possible release of water from the facility by the end of September.
Philippine Atmospheric, Geophysical and Astronomical Services Administration hydrologist Sonia Serrano warned of such a possibility as Pagasa projected rainfall to increase next month and bring Magat’s water to spilling level.
“If that happens, release of water from Magat is likely,” she said, adding that Magat’s wet season spilling level is 190 meters.
Pagasa reported Magat’s water level at a lower 172.18 meters as of 6 a.m. Saturday.
The risk for flooding increases if Magat water’s release coincides with downpour, Pagasa hydrologist Jason Bausa warned.
Such downpour can cause overspilling in waterways where Magat water discharges, he noted.
“Communities concerned must be alert and heed government advisories on the matter,” he said.
Inaugurated in 1982, Magat Dam provides water for irrigation, power production as well as domestic, industrial and commercial use.
The dam is within the Cagayan river basin, noted Pagasa.
Pagasa earlier forecast September rainfall in the basin to reach almost 433 mm.
According to the environment department, the Cagayan river basin covers 123 municipalities in the Cagayan Valley, Cordillera and Central Luzon regions.
Pagasa’s forecast means rainfall in such regions next month could reach 331 mm, 464 mm and 472 mm, respectively.
This week, Pagasa said two to four tropical cyclones are possible this September within the Philippine Area of Responsibility.
Weather systems that may affect the country from September to February next year are the enhanced southwest monsoon, severe thunderstorms, inter-tropical convergence zone, low-pressure areas, tropical cyclones, tail-end of cold fronts and ridge of high-pressure areas, Pagasa said.
‘Habagat’ will transition to the northeast monsoon or ‘amihan’ around October, Pagasa added.