RP’s longest tunnel completed soon

CABANATUAN CITY — The installation of the country’s first giant underground transbasin tunnel is expected to be completed within this month, an official of the build-operate-transfer (BOT) contractor of the $580-million Casecnan Multipurpose Irrigation and Power Project (CMIPP) said yesterday.

Robert Eugenio, assistant vice president of the CE Casecnan Water and Energy Company, Inc. (CECWECI) told The STAR that the concrete-lined tunnel, is practically complete and will become operational in March next year barring any unforeseen delays.

Eugenio said that the tunnel is easily "one of the biggest tunneling projects in Asia."

The main tunnel, whose construction started in 1995 has a diameter of 6.5 meters and is 26.27-kilometers long. It will divert water from the Casecnan and Taang Rivers in Nueva Vizcaya to the Pantabangan Dam and will ensure year-round irrigation to 102,000 hectares of existing areas serviced by the National Irrigation Administration-Upper Pampanga River Integrated Irrigation Systems (NIA-UPRIIS).

It will also generate 50,000 hectares in new irrigable areas, mostly in Nueva Ecija.

The CMIPP is a flagship project of both the Ramos and Estrada administrations.

Engineer Alexander Coloma, project manager of the NIA-Casecnan’s irrigation component whose office is directly in charge of monitoring the tunneling works, said that the BOT component, which consists of the construction of the underground tunnel and the power plant and switchyard and other infrastructure works, is 94.13 percent complete.

He said 26.14 kilometers or 95 percent of the 26.27-kilometer long tunnel has been completed.

"In fact, some of the teams working in the tunnel site have already dis-assembled and dismantled the giant tunnel-boring machines which means the job is practically complete," Coloma said.

He added that pre-commissioning and testing or a dry-run operation of the tunnel will be made in January and February in time for its full operation on March 31 next year.

In addition, the BOT phase completed the construction of 78 kilometers of access roads and seven concrete bridges.

Actually, the tunnel was supposed to be completed on Nov. 27 last year but this was moved to July 27 this year. This was later reset to March 31,2001.

The delay was reportedly caused by "geo-technical" and mechanical problems in the tunnel section due to loose rock formation which rendered the tunnel-boring machines ineffective. Bad weather also slowed down slope protection work, reports said.

Despite suffering some delays, Coloma said they are hopeful the tunnel will be completed this month and will become operational by March 31 as re-scheduled.

Only drill and blasting activities are being made where rocks are drilled and blasted by dynamite.

Ric Joson, NIA-Casecnan assistant project manager, said the irrigation component, which involves construction of a 64-kilometer long superdiversion canal (SDC) and which will be finished in 2004, is now 24.55 percent complete.

He said that 16.53 kilometers of the SDC are now being constructed, including 12 bridges and three canal siphons.