This, as the National Irrigation Administration (NIA) will rehabilitate two smaller dams that feed from the giant Pantabangan Dam in Nueva Ecija.
Engineer Carlito Gapasin, manager of the operations and institutional division of the NIA’s Upper Pampanga River Integrated Irrigation Systems (UPRIIS), told The STAR that the rehabilitation of the Pampanga Bongabon River Irrigation Systems (PBRIS) and the Peñaranda River Irrigation Systems (Penris), which will involve the construction of bypass canals, will go full-blast starting December this year and will extend up to May 2007.
As a result, Gapasin said farmers will no longer have a dayatan or dry cropping season for the 7,580 hectares of ricefields which the two dams service. Traditionally, farmers in these areas produce an average of 38,000 metric tons or 760,000 cavans of palay, valued at P380 million.
Gapasin said the rehabilitation of the Penris Dam would affect farmers in the Nueva Ecija towns of San Isidro and Cabiao and Gapan City, the Pampanga towns of Arayat and Candaba, and San Ildefonso in Bulacan.
On the other hand, the rehabilitation of the 18.6-kilometer PBRIS main canal would affect farmers in the towns of Sta. Rosa, San Leonardo and Jaen and Cabanatuan City.
He said the twin projects are part of the irrigation component of the Casecnan multipurpose irrigation and power project.
Engineer Alex Coloma, senior assistant project manager of NIA-Casecnan, said the rehabilitation of the two dams would cost P1.1 billion.
Casecnan Dam diverts water from the Casecnan and Taang rivers in Nueva Vizcaya to the Pantabangan Dam, which the NIA-UPRIIS operates, through a 26-kilometer underground tunnel.
With the Casecnan Dam fully operational, the Pantabangan Dam was able to augment its irrigable area to a maximum 102,000 hectares in addition to some 35,000 hectares in new areas.
Starting April 30, Gapasin said the NIA-UPRIIS will cut off irrigation from the Pantabangan Dam to give way to the initial work on the two dams in May and June.
He said the water cut-off will have no effect on farmlands since it will be carried out between the two cropping seasons.
Irrigation will resume in July during the start of the wet cropping season, which runs up to November.
Although farmers may lose a huge potential income, Gapasin said they would benefit from the rehabilitation projects in the long term since the canals would become more efficient.
"At present, these canals are under-capacity because of siltation," he said, adding that water is currently being released at 22 cubic meters per second (cms).
Once the two dams are rehabilitated, he said water will be released at a rate of 30 cms.
Gapasin said NIA administrator Baltazar Usis and NIA-UPRIIS operations manager Antonio Nangel both support the projects because of their long-term benefits to farmers.