NIA Central Office – The National Irrigation Administration-Magat River Integrated Irrigation System (NIA-MARIIS) has advised residents of the Provinces of Isabela and Cagayan in Region II of its water release from the Magat Reservoir to maintain safe water level of the Magat Dam on Monday, November 9, 2020, two (2) days before Typhoon Ulysses (Vamco) made its first landfall in Patnanungan, Quezon, at 10:30 PM of November 11, 2020.
With the heavy downpour brought by Typhoon Ulysses that triggers massive flooding in many parts of the country, it also pushed the water level of Magat Dam beyond normal. NIA-MARIIS-DRD Flood Forecasting and Early Warning Dam Operations updates that the reservoir water level is now at 192.15 meters, which is 0.85 meters close to its spilling level of 193 meters above mean sea level as of 6:00 AM today, November 15, 2020. The reservoir inflow is at 1,020 cubic meters per second (cms) and outflow at 834 cubic meters per second (cms) with one (1) spillway gate opened at two (2) meters.
Pre-releases of calibrated opening of dam gates must be made before the occurrence of typhoon or unusual weather disturbances. This is to minimize, if not to avoid large Magat Dam discharges before spilling level will be reached. Prior to Typhoon Ulysses, five (5) typhoons had affected Isabela and Cagayan Valley and almost the entire Luzon, causing continuous rain for almost two (2) months. During this period, two (2) gates opened or an equivalent of four (4) meters were opened to reduce water containment at the Magat Reservoir. However, as water inflow from our Magat watersheds continually increases, additional gates must be gradually opened to maintain the safe level of the Magat Reservoir. The continuous rains upstream of Magat Dam contributed to high inflows, while rivers along the Cagayan River had also reached its maximum capacity, causing river overflows, not only to the Cagayan River but its adjacent areas.
The Magat Dam Protocol on Dam Discharge and Flood Warning Operation is strictly observed during this flood operation. In here, procedures to follow before, during and after typhoon are stated for dam operations. NIA-MARIIS, in coordination with stakeholders, is closely monitoring the dam status and operations. The system, as its practice, is making sure that all concerns regarding the dam status are addressed immediately and properly. Dam and Reservoir Division Manager Eduardo P. Ramos and his team is in close coordination with Office of Civil Defense (OCD), Provincial Disaster Risk Reduction Management Council (PDRRMC), PAGASA, Regional Agricultural Fisheries Extension Network group and other concerned local government offices prior, during and after water releases. Different mediums such as TV, radio, print, social media, emails, Short Message Service (SMS) and sirens are used to disseminate information of current situation of Magat Dam and its water releases. All stakeholders are kept posted and updated as to the actual scenario of the water volume that may be flowing into their place on an hourly basis through SMS.
NIA-MARIIS officials have warned residents living near low-lying areas, particularly those adjacent to and along Magat River and Cagayan River to move to higher and safer places as the dam continues to release water starting November 9. It is necessary to release water from the reservoir for purposes of preventing the dam from reaching its critical level of 193 msl that may compromise its structural integrity and may result to a catastrophe to nearby municipalities and more impact on a widespread flooding in Region II.
Magat River is only one of the 18 river tributaries of the whole Cagayan River basin. As compared to other River Systems, it is only Magat River which can delay the surge of flood water through its Magat Dam.
Magat Dam is a catch basin of 4,143 square kilometers of watershed and eight (8) upstream rivers namely Alimit, Lamut, Ibulao in Ifugao Province and Abian, Matuno, Sta. Cruz, Marang, Sta. Fe river in Nueva Vizcaya. With the Magat Reservoir and Magat Dam to regulate the gush of water from these sources, flash flood and greater flooding at low-lying areas, which could have caused greater damage to life and property is minimized, if not prevented.
NIA Administrator Ricardo R. Visaya and NIA-MARIIS call on residents to continue to stay vigilant and take appropriate action against landslides and flashfloods most especially in the prevalence of COVID-19 Pandemic.
**For questions and/or clarifications, you may contact:
EDEN VICTORIA C. SELVA
Acting Department Manager
NIA Public Affairs and Information Staff
Landline: (02) 8921-3741