Quake impact review for megadam urged

ILOILO CITY—Groups opposing the construction of an P11.2-billion multipurpose megadam in Iloilo province have called for an earthquake impact assessment on the project in the aftermath of the massive devastation brought by the 7.2-magnitude temblor  that ravaged Bohol and Cebu provinces.

The nongovernment organization Dagsaw (Panay-Guimaras Indigenous People’s Network) said a “thorough” earthquake impact study similar to those made in the West Valley Fault in Metro Manila and in Iloilo City should be undertaken to validate claims by the National Irrigation Administration (NIA) on the safety of the Jalaur River Multipurpose Project II (JRMP II).

The NIA has assured the public that the multipurpose dam project to be built in Calinog town, Iloilo, could withstand an intensity-9 earthquake.

Engineer Jesus Datoon, NIA assistant project manager, earlier said the dam would be built on solid rock formation and designed to withstand strong earthquakes.

But Dagsaw executive director Cynthia Deduro said an area assessment related to the project was necessary because of the proximity of the project site to the West Panay Fault.

Deduro said a massive earthquake could also hit Panay Island similar to the estimated 8.2-magnitude  earthquake that hit the island in 1948.

The “Lady Caycay” earthquake destroyed or seriously damaged houses, bridges, churches and other structures mostly in Iloilo.

The Philippine Institute of Volcanology and Seismology (Phivolcs) earlier gave the assurance of safety of the site of the dam project.

The main dam and reservoir would be located 11 kilometers from the fault line and the nearest component dam is 5 km east of the fault line, according to a Phivolcs report.

But Deduro said the recent earthquake in the Visayas showed the extent of the damage of a massive earthquake even in areas far from the epicenter and fault line.

“The problem with JRMP II does not lie only in ensuring the durability of particular infrastructure like the megadam but the area impact of a repeat of the Lady Caycay earthquake in 1948 or worse, by the confirmed catastrophic tremor generator—the West Panay Fault which is only 11 km away from the planned site of the megadam,” she said.

The JRMP II is the second of a two-stage project aimed at the multipurpose use of water of the Jalaur River, one of the major rivers of Panay Island.

It aims to develop irrigation systems, generate hydroelectric power and provide domestic and industrial water supply.

The project involves the construction of three dams (Jalaur reservoir, afterbay and catch dams), a 6.6-megawatt hydro power plant and an 81-km highline canal in Calinog  town in Iloilo.

But opponents of the project have called on the government to build several small hydro-dams instead of a megadam.

They said megadams posed greater risks and would trigger massive floods when these  overflow or collapse due to strong earthquakes.