In case of soil movement inducing a magnitude 7.2 earthquake, can the Angat Dam survive this intact?
Thus, Governor Wilhelmino M. Sy-Alvarado of Bulacan raised the issue of the possibility of an earthquake breaking Angat Dam.
“Can you imagine 60 cubic meters of water per second cascading out of control from the highest slope of the mountain?” he told the Philippines Graphic. “It is unimaginable.”
“If such a rush of water hits us, where will we end up?” he pointed out. “According to the earthquake study for Metro Manila, if the area was hit by a 7.2 magnitude earthquake, 60% of buildings in the metropolis will collapse. There will be an estimated 36,000 immediate deaths while numerous fires break out in several areas,” he added. “Put that earthquake in an area where a dam breaks. What will happen in case Angat Dam breaks? Imagine a 210-meter water level cascading faster than a bullet with all the boulders and illegally cut logs as high as one-and-a-half Meralco posts. Millions could die.”
“Angat Dam is an old dam,” he added. “When I first made a speech about the possibility of dam break, Angat Dam was already 46 years old. And the dam was finished in 1967, making it 50 years old now. It has never been retrofitted for earthquakes. Can it resist a 7.2 magnitude earthquake?”
When he was still vice governor of Bulacan, he gave such a speech on Sept. 8, 2009. He emphasized the danger, saying “Given its present state, Angat Dam is an accident waiting to happen!”
Experts have agreed such an earthquake will occur. It’s not a matter of if, it’s a matter of when. That’s a Big Bang. And such a Big Bang earthquake should not just be about Metro Manila, it should also include the dams in Bulacan.
“Also connected to this, my administration dauntlessly lobbied for the assessment and careful evaluation of the stability of the Angat Dam because I strongly believe that the safety of Angat Dam is a national security concern because it is the main source of potable water for Metro Manila,” he added. “Aside from that, dam breakage poses an unimaginable danger to lives and properties of those living downstream of the Angat River System in case an earthquake affects the structural integrity of the dam since it was found out that underneath the dam is a splay. At present, the rehabilitation of Angat Dam is 55% accomplished.”
But he was not entirely relying on just man-made efforts.
“Then when I became governor, I put up tarpaulins that featured a biblical quote: ‘If my people who are called by my name will humble themselves and bow down and pray and seek my face and turn from their wicked ways, then I shall hear their prayers, forgive their sins and heal their land.’”
It was a reminder that God helps those who help themselves.