MANILA, Philippines — The National Irrigation Administration (NIA) denied Tuesday that the release of water from the Magat Dam was the main contributor to massive flooding in Cagayan and Isabela following the onslaught of Typhoon “Ulysses” (international name: Vamco), which affected thousands of residents there.
Speaking to lawmakers during a hearing at the House of Representatives, NIA administrator Ricardo Visaya shifted the blame instead to illegal logging, mining and quarrying in the Cagayan Valley region.
Related Stories
“The Magat Dam was not the major cause of flooding in Cagayan,” Visaya said partly in Filipino. “If we just implemented activities against illegal logging, mining and quarrying, maybe we can prevent the flooding of Cagayan River.”
To prove his point, Visaya presented to House lawmakers a matrix which showed the peak inflow of water to Magat Dam and the amount of water it released during five weather events, including when Typhoon Ulysses hit.
Data he presented showed that when Typhoon “Emong” (international name: Chan-hom) hit in 2009, the peak inflow of water to Magat Dam was 10,229 cubic meters, which caused the dam to release up to 8,068 cubic meters of water. At the time, the highest water level in Cagayan River at Buntun Bridge in Tuguegarao City was at 9.82 meters.
The same data also showed that the peak inflow during the onslaught of Ulysses was less than that of Emong, with 7,128 cubic meters of water entering Magat Dam and 6,706 cubic meters of water being released. Yet, the data showed, the Cagayan River at Buntun Bridge measured at 13.2 meters.
NIA: Magat Dam started releasing water on November 9
Visaya also denied that they opened the gates of the Magat Dam suddenly, presenting data which showed that the NIA began opening gates of the dam as early as November 9, two days before Ulysses made landfall over Quezon province.
However, the same data showed that the NIA was initially slow to open dam gates and only rapidly opened them after Ulysses made landfall.
The NIA initially opened one gate at a height of one meter on November 9 at 3 p.m., then opened two gates at a height of two meters by 6 p.m. on the same day. But in a span of just six hours, the NIA opened all gates of the Magat Dam on November 12.
Visaya, however, reiterated that sufficient warnings were issued prior to them opening the gates of Magat Dam.
A total of 73 people died due to Ulysses, 24 of whom came from Cagayan Valley.