Aghon rains allow NIA-7

irrigation coverage reset

TAGBILARAN CITY, Bohol, May 25 (PIA)—The rains brought about by tropical depression Aghon came as a good preparation for the release of the irrigation waters at the Zamora dam in Talibon, and Bayongan Dam in San Miguel, as this allows the National Irrigation Authorities to recalculate their areas of irrigation coverage.

Set to release its impounded water to allow rice farmers in their service areas to make the necessary land preparations for this season’s cropping, these dams have scheduled their water release a week later than the giant Malinao Dam, which started its release May 20, considering that the start of the regular cropping season has started.

Without the rains, Malinao, which relies on the Wahig and Pamacsalan Rivers has a total 5,000 hectares of rice lands set for irrigation but with issues like siltation, it could only get to 4,150 hectares of farmlands, in two croppings, using a ladderized system, explains NIA authorities.

With the devastating effects of the El Niño leaving cracked farmlands, the water percolation in the farms get higher that NIA would need more water to irrigate these as the seepage would be too much, lessening the amount of coverage for every cubic meter of irrigation water, explains Engr. Aproniano Añora, during the recent Kapihan sa PIA.

Hydrologists however aver that if rains would come earlier, not only would the dams be helped in storing more water, the farms where the rains fall, could get the water it would need to initially set the cracks close.

Any rain falling anytime would increase the capacity of the dams to extend its irrigation water to other farms un-programmed to get the water this cropping season.

At 151.56 as of May 24, and already diverting its water to Bayongan Dam, Malinao has released its water for irrigation to downstream areas as of May 20, targeting around 600 hectares for this release, according to Engr Aproniano Añora, at the recent Kapihan sa PIA.

Any additional inflow, like rains, could further expand its water to 9 irrigation associations or a total target of 1,975 hectares, he said. Malinao, on normal times, was designed to get to 4,740 hectares but NIA has programmed only 4,550 hectares in two cropping.

For Bayongan Dam, which only has a creeks and small tributaries to feed its impounding, getting some diverted water from Malinao helped but the recent rains could further expand its target areas to cover from 1,030 hectares from its 11 million cubic meters of available water: 180 hectares in Trinidad and 850 hectares in Ubay, for this cropping, added Engr Joselito Mumar of the Bayongan Dam.

With the tropical-depression-brought rains, Bayongan sees a recalculation considering that the water could expand more irrigation capacity, he added.

As to Capayas Dam in Ubay, Engr. Andres Carnice said at present and with the El Nino hitting record dry spell, the target is for 98 hectares to be covered, but with a high percolation, NIA is reducing its coverage to 55 hectares.

However, with the rains coming already, he said they could expand their coverage, hoping to get to the 377 hectares as targeted, and based on the ladderized system, could serve to more irrigation associations.

As to Benliw Dam, Engr Carnice said the current volume is 1.6 million cubic meters, programmed for 223 hectares. The release however is set for 160 hectares, set for release on June 3, following local traditional fiestas in the service areas.

The additional inflow from the recent rains could get Benliw irrigation water improve on the 160 hectares, serving more areas of the 233 as targeted this year. (rahc/PIA-7/Bohol)

BAD AS IT MAY SEEM