By Ma. Cristina Arayata | Philippine News Agency
Spillway gates of San Roque and Magat dams will be opened on Wednesday as Tropical Storm Kristine continues to batter parts of the country with heavy rainfall.
The National Power Corporation (Napocor) said San Roque’s reservoir elevation needs to be lowered in anticipation of heavy inflow due to Kristine.
As of 8:00 a.m., the dam’s water level reached 275.98 meters (m), still below its normal level of 280 m.
Napocor said San Roque’s Gate 2A will be opened at 0.5 m, with an estimated discharge speed of 53 cubic meters per second (cms).
Meanwhile, as of 9:00 a.m., Magat Dam’s water level reached 182.28 m, below its 193 m normal level.
Magat Dam’s inflow level is measured at 194.33 cms, while the total outflow stands at 399.50 cms.
One spillway gate of Magat Dam was opened at 1 m, increasing the discharge of water into the river by 132 cms.
“The public, especially those in downstream areas, are advised to stay updated and take necessary precautions as water levels are being managed to ensure safety amid ongoing weather conditions,” the Magat Hydroelectric Power Plant (HPP) was quoted as saying.
The total discharge to the river system, combining spillway and HPP outflows, is recorded at 206.90 cms, the report added.
As for the other dams, La Mesa’s water level measured 79.50 m, less than a meter from its spilling level of 80.15 m.
The other dams’ water levels (and their normal levels) are Angat, 197.63 m (210 m); Ipo, 100.80 m (101.10 m); Ambuklao, 748.89 m (752 m); Binga, 573 m (575 m); Pantabangan, 205.30 m (216 m); and Caliraya, 287.11 m (288 m).
Energy Secretary Raphael Lotilla said in anticipation of the spilling operation of San Roque Dam, the NPC issued the notice on preparatory phase of dam discharge warning operation 24 hours before gate opening to the Office of Civil Defense in Region 1 and to the provincial and municipal Risk Reduction Management Offices of Pangasinan.
“This is to advise them to be on alert and take the necessary preparatory measures for the possible spilling operation of San Roque Dam,” Lotilla said.
For Binga Dam spilling operations, the notice on dam discharge warning operation was issued at 9:00 a.m. of Oct. 22 or six hours before gate opening at 3:00 p.m.
“These are in consonance with the amendment of NPC dam protocols where the notification period for the initiation of preparatory measures for spilling operation at San Roque Dam is 24 hours and for Binga Dam it is 4 hours,” he said.
Other NPC dams such as the Angat and Caliraya are not expected to spill since water levels are low in Angat and the rain band of Tropical Storm Kristine is veering away from these areas, Lotilla said.
