NIA to check Angat Dam safety in case of quake

CABANATUAN CITY– National Irrigation Administration chief Antonio Nangel is forming a technical working group to look into the structural soundness of the Angat Dam.

This, amid concerns over the dam’s safety in the event of a powerful earthquake similar to the one that devastated Japan because it is sitting on a fault.

“We will study it. I will form the technical working group to look into its physical aspects,” Nangel said.

Nangel was responding to statements of Bulacan Gov. Wilhelmino Sy-Alvarado who suggested that experts immediately inspect the 43-year-old dam at the soonest possible time due to the fact that it is sitting on the Marikina Western Valley fault.

In his weekly radio program “The Governor’s Hour,” Alvarado said studies made by the Philippine Institute of Volcanology and Seismology showed that the dam is sitting on the fault and that its underground base could have already been compromised through the years.

The Marikina fault extends from Angat Dam to Taal Lake in Batangas province. It moves between 200 and 400 years and can generate a 7.5 magnitude earthquake.

Alvarado said it is high time for the national government to consult foreign and local experts on the condition of Angat Dam since most dams have a life span of 50 years.

Angat Dam is a multi-purpose dam in Barangay San Lorenzo, Norzagaray, Bulacan. Constructed in 1967 at a cost of P315.3 million as part of the Angat-Ipo-La Mesa water system, the 131-meter high, 568-meter long dam irrigates 27,000 hectares of farmlands in Bulacan, provides 97 percent of the water supply of Metro Manila, and serves as a flood control mechanism in Bulacan.

It also generates power through its hydroelectric plant, which has an installed capacity of 256,000 kilowatts.

Nangel, however, said the Angat Dam, like the Pantabangan Dam in Nueva Ecija, is safe.

“At the time it was designed, Angat Dam was found to be stable. Even all the dams that we have in the Philippines are all safe and we see no problem,” he said.

Nevertheless, Nangel said he would take Alvarado’s concerns into consideration and assign a team of technical experts from the NIA to conduct an inspection of the dam, considered the country’s third largest after the Pantabangan Dam and Magat Dam in Isabela.

Earlier, Nangel said the Pantabangan Dam is so sturdy that it can withstand an earthquake of up to Intensity 10 on the open-ended Richter scale.

Pantabangan Dam also lies near the Digdig fault in Carranglan, Nueva Ecija. -- MG