Residents in low-lying communities in Isabela and Ifugao were warned against possible flooding as Magat Dam will conduct spilling operations on Saturday noon, Sept. 24, in anticipation of the heavy inflow during the passage of tropical storm Karding.
In an advisory issued on Friday noon, Sept. 23, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said areas that are likely to be affected are the municipalities of Ramon, San Mateo, Aurora, Cabatuan, Luna, Reina Mercedes, Burgos, Naguilian, and Gamu—all in the province of Isabela, and Alfonso Lista town in Ifugao.
It pointed out that water levels along the Magat River and the main Cagayan River Basin are still below the alert level, as of Friday noon.
In the PAGASA press conference on Friday, Hydro-Meteorology Division weather facilities specialist Edgar Dela Cruz said that Magat Dam may overflow during the passage of the storm.
According to weather specialist Raymond Ordinario, Karding is still likely to make landfall over the Cagayan-Isabela area on Sunday morning, Sept. 25.
Magat Dam is located on the Magat River at the boundary between Alfonso Lista, Ifugao and Ramon, Isabela
“Mataas ang possibility na magspill ang Magat Dam lalo doon ang dadaanan ng bagyo (There is a high possibility that the Magat Dam will spill, especially since the typhoon will pass through there),” Dela Cruz said in a PAGASA press conference.
The dam’s level of 187.63 meters as of 6 a.m. is just less than 3 meters from its 190-meter normal high water level.
Based on the PAGASA’s forecast basin rainfall for the next 72 hours, Dela Cruz said that Magat Dam’s reservoir may receive 21 millimeters of rainfall.
This means that the dam will possibly reach its spilling level of 190 meters.
Magat Dam is scheduled to open one gate with a one-meter opening, and will discharge 200 cubic meters per second of water on Saturday noon.