PREEMPTIVE MEASURE. San Roque Dam in San Manuel, Pangasinan. On Monday (Nov. 11, 2024) at noon, the dam opened one of its gates at 0.5 meters to release 63 cubic meters per second as a precautionary measure in anticipation of heavy rainfall caused by Typhoon Nika (Toraji). INQUIRER file photo / WILLIE LOMIBAO
LINGAYEN, Pangasinan聽鈥� The San Roque Dam in San Manuel, Pangasinan opened one of its gates at 0.5 meters and released water at 63 cubic meters per second starting noon Monday amid the expected inflow due to .
National Power Corporation-San Roque Dam Office flood operation manager Teresa Serra said in a statement that the pre-release is necessary as the reservoir elevation must be decreased.
She earlier said the total water release from the dam, including the turbine discharges to generate power, amounts to around 200 to 230 cubic meters per second (m3/s), which flows to the Agno River and its tributaries, which has a capacity of around 1,400 m3/s.
鈥淭he water release is minimal. The rivers can hold it and would not cause flooding,鈥� she said.
Although the typhoon would bring moderate to heavy rainfall to Pangasinan, the water inflow in the dam is anticipated from the mountainous areas, including Binga and Ambuklao dams, according to Provincial Disaster Risk Reduction and Management Office (PDRRMO) operations and training head Vincent Chiu.
鈥淭he province鈥檚 river systems are still below normal level so the water release should not pose threat of flooding since it is a precautionary measure,鈥� he said in a phone interview.
The dam level is at 278.07 meters above sea level as of聽8 a.m.聽The normal high level is 280 meters.
Chiu said the province is on red alert status, with teams prepositioned in strategic areas ready to assist local government units for rescue and other operations.
PDRRMO staff, the Army, and the police are also on standby, he said.
Chiu said they have asked their local counterparts to implement preemptive or forced evacuation in high-risk areas, including the 14 localities where a storm surge advisory is up.
The northeastern portion of Pangasinan (municipalities of San Nicolas, Natividad, San Quintin, Sison, San Manuel, Umingan and Tayug) is still under Tropical Cyclone Wind Signal No. 2, while the rest of the province are under Signal no. 1 as of posting time.
Magat Dam
In another notice issued Monday, the National Irrigation Administration-Magat River Integrated Irrigation System Dam and Reservoir Division said one of the dam鈥檚 gates would also be opened by聽4 p.m.
鈥淕ate 4 will be opened 1 meter with an approximated discharge of 130 m3/s,鈥� Magat flood operation manager Carlo Ablan said.
Magat Dam was at 181.95 meters elevation as of聽8 a.m., far from the normal high level of 190 meters.聽(With a report from Leilanie Adriano/PNA)