BAYOMBONG, Nueva Vizcaya: The heavy downpour brought by Typhoon Luis (international name : Kalmaegi)pushed the water level of Magat dam to 187.5 meters, the National Irrigation Administration (NIA) reported on Monday.
Engr. Saturnino Tenedor, the dam’s instrumentation and forecasting officer, said the increase was the result of 3,000 cubic meters per second inflow of water brought by the typhoon which hit the Cagayan Valley region on Sunday night.
Tenedor said the volume of water is now 12.5 meters more than the normal level of 175 meters coming from the dam’s major sources which are the watershed areas, the upstream Magat River in Nueva Vizcaya and the Ibulao River in Ifugao which swelled due to the rains.
He said the reported spill which was conducted was a normal procedure for electric generation purposes while excess water were for irrigation explaining that “there is no cause to be alarmed of any flooding downstream.
The Magat dam, once Asia’s biggest power and irrigation facility located along the Isabela-Ifugao border, is also the second biggest power provider among hydro-dams in Luzon contributing at least 380 megawatts of electricity for the Luzon grid.
The Magat dam can also irrigate at least 80,000 hectares of farmlands in Isabela and parts of Cagayan and Quirino provinces.
“The inflow of water from the dam’s major sources is now diminishing at the rate of 1,000 cubic meter per second and could hardly reach the critical level of 193 meters,” Tenedor explained.
He said there can only be spillage when the water level at Magat dam has reached 190 to 193 meters especially when the calculated inflow of water volume is so big that it will last for a few more days.
“We are more than five meters short to reach the critical level of 193 meters and would need a continuous large volume of water inflow to the dam before we need to release water to lower down the level of water,” Tenedor said.
He said that it is not yet necessary to release water from the reservoir for purposes of preventing the dam from reaching its critical level.
Last month, the dam’s water level fell to 170.3 meters. In July, the level dropped to its lowest in three years at 160.46 meters which is less than a meter above its minimum operational level to generate power.
NIA officials said 160 meters is the minimum operational level for the Magat Dam to continue generating power. In July 1991, the more than 30 years old dam recorded an all time low of 149 meters.
Meanwhile, Typhoon Luis forced families to evacuate several areas and toppled trees and electric posts in Region 2.
Cagayan and Isabela were the worst hit by the typhoon which packed maximum sustained winds of 120 kph near the center and gustiness of up to 160 kph.
Signal no. 3 was hoisted over Cagayan, Babuyan, Calayan, Apayao, Ilocos Norte, Abra, Kalinga, Mt. Province and Ilocos Sur.
Areas under signal no. 2 include Batanes, Isabela, Ifugao, La Union, Benguet, Nueva Vizcaya and Pangasinan, while areas under signal no. 1 include Tarlac, Zambales, Pampanga, Bulacan, Nueva Ecija, Quirino and Aurora.
Initial reports from the National Disaster Risk Reduction and Management Council (NDRRMC) said that 122 families were evacuated in Gonzaga town and 71 families were moved out in the town of Aparri.
NDRRMC said strong winds and heavy rains felled trees and electric posts in the highways of Amulung, Alcala, Gattaran, Iguig and Solana and shut down power in Cagayan.
In Amulung town, some 200 hectares of cornfield and 20 hectares of riceland were severely damaged by strong winds and heavy downpour while the Maginling overflown bridge between Tuao and Piat towns was not passable.
Meanwhile, Isabela Gov. Faustino Dy 3rd confirmed that hundreds of families were evacuated in different coastal areas.
Dy said 88 families were evacuated in Maconacon, 136 families in Divilican, 85 families in Dinapigue and 100 families in Palanan.