The Department of Environment and Natural Resources (DENR) Regional Executive Director Benjamin T. Tumaliuan stated that the rainfall measurement in a given time can determine the amount of water outflow, the rise of the Cagayan River at a certain level, and the barangays that will be affected by the flooding as exemplified his study, “Development of Flood Forecasting and Early Warning System for Cagayan Valley.”

RED Tumaliuan said that if the rainfall level in Isabela, Quirino, and Nueva Vizcaya exceeds 50mm, inflow to Magat Dam ranges from 4,000 to 5,000 m3/sec and outflow reaches 5,000 m3/sec with no rainfall in Cagayan, 17 municipalities in Isabela will be flooded within 12 hours and Tuguegarao City within 24 hours.

Likewise, in case of heavy rainfall throughout the region with more than 50mm level and the outflow of Magat Dam reaches 5,000 m3/sec, 18 municipalities will be flooded especially those below 35m above sea level in Cagayan and 45 in Isabela.

RED Tumaliuan also stated that the siltation problem in Cagayan River is not only caused by deforestation but also due to economic activities such as road construction and farming. Note that the heavy siltation in said river has been causing the flood in Cagayan especially in low lying areas.

He also called for a more intensified IEC campaign on weather information, and disaster responses and mitigation and urged the region to create a model of communication channel to effect an efficient early warning, contingency planning, and quick response during natural disturbances. The system shall be composed of concerned Regional Line Agencies and the Regional Disaster Risk Reduction Management Council (RDRRMC) 2.