Pagasa hydrologist expects Magat Dam to close some gates

MANILA, Philippines — A hydrologist at the state weather bureau on Saturday said he expects Magat Dam  to close some gates as there is now more outflow than inflow.

In a phone interview with INQUIRER.net, Richard Orendain, a hydrologist at the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa), said there is a chance that the gates of the dam will be closed as more water is now going out than coming in.

The Magat Dam is on the Magat River, a major tributary of the Cagayan River.

“Ngayon as of 2 p.m., two gates na lang, four meters iyong total opening and iyong elevation ng Magat Dam is 192.18 [meters], with total discharge of 1,340 cms [cubic meters per second],” Orendain said when sought for updates about the Magat Dam, which was believed to have caused massive flooding in the region.

(Now as of 2 p.m., there are only two gates open with four meters of opening and the elevation of Magat Dam is 192.18 meters with a total discharge of 1,340 cms.)

“Medyo maliit na iyong inflow so we are hoping magsasara na ng gate or magbabawas ng opening gate siguro in a couple of hours kasi mas malaki na ang outflow sa inflow,” he further said.

(There is already a decrease in the inflow of water so we are hoping that some of the gates will be closed in a couple of hours as the outflow is now greater than the inflow.)

He noted that Magat Dam has been releasing water since Nov. 9, when Typhoon Ulysses was still a tropical depression.

The spilling level of the Magat Dam is at 193 meters, Orendain said.

Protect dam integrity

Dam operators release excess water to protect the integrity and structure of dams, Orendain explained.

If this process will not be followed, more people will suffer, he further said.

“Hindi pwedeng pigilan iyong [pag-release] ng tubig hanggang sa puno ang dam. Ang dam may specific na design kaya may tinatawag na spilling level ibig sabihin hanggang doon lang ilalagay mo diyan. Otherwise, masisira iyong disenyo niya, which is huwag naman sana,” Orendain said.

(We can’t release water when the Dam is still at the maximum water level. The dam has a specific design that is why we have a spilling level which means the water should stay at a specific level. Otherwise, the design will be destroyed, which is what we don’t want to happen.)

“Mas delikado, mas malaking baha, masa maraming tao ang hindi natin alam kung ano ang mangyayari. Ibang sitwasyon iyon,” he added.

(This will be more dangerous, expect more destructive floods and more people will experience the impacts. That is another situation.)

/MUF