Lower water allocation likely in Magat Dam

By Catherine Teves

January 11, 2022, 6:39 pm

<p><em>File photo</em></p>

File photo

MANILA – Magat Dam in northern Luzon is facing next month the possibility of having reduced allocation of water for irrigating its palay-growing service areas totaling nearly 86,000 hectares.
The expected continuing dip in Magat's water due to rainfall shortage may prompt a reduction, said Edwin Viernes, acting head of Flood Forecasting and Instrumentation Section of Dam and Reservoir Division (DRD) of National Irrigation Administration-Magat River Integrated Irrigation System.
"Reduction in Magat's allocation or irrigation diversion requirement is likely if there will be no favorable inflow that can considerably raise water in the dam," he said Tuesday, adding that water flowing into the facility is only about 75 percent of what it normally receives.
However, there is low possibility for an anticipated favorable inflow soon as Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) forecast only one or even no tropical cyclone (TC) in Philippine Area of Responsibility (PAR) this month.
TCs are weather systems that may bring over Magat Dam's watershed rainfall which can increase its inflow to considerably raise water level.
Historical PAGASA data show that during January, TCs that form inside PAR either do not landfall in the Philippines or strike the Visayas' eastern section -an area far from Magat- then dissipate or recurve and move away from the country.
Despite Magat's situation, Viernes said this month’s irrigation allocation is 160 cubic meters per second.
The allocation is normal for Magat during January due to high demand for water irrigation to address needs of palay farmers, he said.
Magat may have lesser allocation next month but this will unlikely disrupt cropping activities in those areas since the dam will still be able to supply water, he added.
Viernes said harvesting palay plants in the area generally begins around late February.
Shortage of rainfall over Magat Dam's watershed has been adversely affecting its inflow, thus water level continues to dip, DRD Flood Forecasting, Warning and Hydrology Unit engineer-in-charge Arlen Alejandro said.
"That watershed hasn't received significant rainfall during the past few weeks," she said.
Alejandro forecasts Magat Dam's water level to be around 180 meters this February 15, which is lower than the 184.70 meter-high 6 a.m. water level PAGASA reported for the dam on Tuesday.
Water level in the area during the same period last year was at 191.60 meters, PAGASA said. (PNA)