MANILA – Magat Dam in northern Luzon resumed its spilling operation due to severe tropical storm Maring (international name Kompasu).
The spilling operation started 3 p.m. Tuesday initially using one gate that opened at a height of 1.0 meters to discharge 200 cubic meters of water per second (cms), noted Carlo Ablan, the acting manager of the Dam and Reservoir Division under the National Irrigation Administration-Magat River Integrated Irrigation System.
He said the surge in Magat Dam's inflow due to the previous downpour from "Maring", and expected rain over the facility's watershed, led to the decision to resume spilling operation.
The Magat Dam management already informed the downstream communities about its resumption, he noted.
Likely to be affected are communities in Ramon, San Mateo, Aurora, Cabatuan, Luna, Reina Mercedes, Burgos, Naguilian and Gamu municipalities of Isabela province in northern Luzon's Region II (Cagayan Valley) where Magat Dam is. According to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), Magat terminated its last spilling operation in December 2020 after releasing excess water due to rain from the tail-end of a frontal system and tropical depression Vicky that month.
Spilling operations help keep dams structurally safe by preventing water from rising to and beyond respective normal high levels.
PAGASA reported Magat Dam's 10 a.m. water level on Tuesday at 188.17 meters, still lower than its 193.00 meters normal high but higher than the 187.54 meters water level PAGASA monitored there four hours earlier.
Ablan is not discounting the possibility of Magat Dam eventually intensifying its spilling operation to keep its water safely below the normal high.
"Downpour from 'Maring' already raised Magat's inflow to almost 1,900 cms by 11 a.m. Tuesday, and PAGASA is forecasting further rain, so we're monitoring the situation to see if there's need to intensify spilling operation there," he said.
"Maring" already exited the Philippine Area of Responsibility at 11 a.m. Tuesday, said PAGASA weather forecaster Joey Figuracion.
He, however, said that rain can still be expected despite the exit of "Maring".
For Tuesday, PAGASA forecast light to moderate with at times heavy rainfall over Cagayan Valley, Metro Manila and parts of northern Luzon's Cordillera Administrative Region.
Other areas in Luzon can also receive rain, PAGASA added. (PNA)