As per the Magat Dam’s operations manual, NIA Administrator Ricardo Visaya said, “[i]t is emphasized that there is no provision for the storage of floodwater in the Magat reservoir unless the reservoir is below the full supply level of 193 (meters) when the flood arrives.”
Visaya responded to a question from Marikina Representative Stella Quimbo, who said she had found the dam’s functions included flood control, alongside irrigation and power generation.
The House joint panel is currently conducting investigations on the massive flooding in Cagayan Valley during Typhoon Ulysses.
Visaya insisted that the Magat dam was built to irrigate an area encompassing 85,000 hectares.
“Wala pong function ‘yan flood ng control. It’s only for irrigation,” he said.
He added that dam operators also try to ensure the dam “absorbs” some of the floodwaters.
Magat Dam not built for flood control – NIA
“‘Yung Magat Dam natin, kahit walang flood control function, we are trying our best na maka-mitigate pa ng baha. That’s part of our protocol nga eh, kaya ‘yung mga nire-release po na tubig ng Magat will be lower than the inflow. Kasi kung inflow is equal to outflow, talagang dire-diretso ‘yun. Mas delikado po ‘yun,” Visaya said.
Earlier in the hearing, Visaya reiterated that the Magat Dam’s opening of the water gates was not the major cause of the massive flooding in Cagayan and Isabela.
During the inquiry, Visaya showed a matrix which indicated that from November 9 to 14 amid the typhoon, the peak water inflow at Magat Dam was at 7,128 cubic meters per second. Still, the dam released only at 6,706 cubic meters per second.
Meanwhile, Buntun Bridge’s water level, which measures Cagayan River’s water level, was at 13.2 meters, Visaya added.
The NIA chief said that looking at the matrix alone, he could already conclude that the opening of Magat Dam’s water gates was not the primary cause of flooding in Cagayan and Isabela.
Visaya also insisted that those who would be affected by the water release were warned ahead of time.