River basins in Metro Manila critical

Published September 15, 2018, 4:22 PM

by Francine Ciasico

By Alexandria Dennise San Juan

Some river basins in Metro Manila are now in critical condition and under alert levels while major dams in Luzon continue to release water as typhoon “Ompong” continues to dump torrential rains while moving away from the country.

Ambuklao Dam (photo courtesy of Kankanaey Igorot Tako Facebook page / MANILA BULLETIN)
Ambuklao Dam (photo courtesy of Kankanaey Igorot Tako Facebook page / MANILA BULLETIN)

The Philippine Atmospheric Geophysical and Astronomical Services Administration said four of the major dams in Luzon – Ipo, Ambuklao, Binga, and Magat – continue to release water as of 5 p.m. Saturday.

The dam release is a precautionary measure to prevent the accumulation of water, according to PAGASA’s Flood Forecasting and Warning Division.

Based on the data from PAGASA, as of 3 p.m., Saturday, the Ambuklao Dam in Bokod, Benguet opened its eight gates at 21.5 meters to release waters that had risen to 752.62 meters, passed to its limit capacity of 752 meters.

Binga Dam, which is also located in Benguet, and connected to Ambuklao through the Agno River System, has opened six gates at 30.5 meters.

Its water level as of 3 p.m. Saturday is already at 577.40 meters which also surpassed its 575 meter normal high-water level.

Orendain said the waters being released by the two dams will flow toward San Roque Dam in Pangasinan, that is also located along Agno River.

PAGASA said San Roque Dam is expected to open its gates as it is nearing its normal high water level limit of 280 meters as rain continues to pour and the two dams in Benguet keep on releasing waters.

Aside from Ambuklao and Binga dams, the Magat Dam connected to the Magat River in Isabela also opened one of its gates at 0.5 meter to avoid reaching its 190 meter critical water level.

The current elevation of water in Magat Dam is already at 187.02 meters as of 3 p.m. Saturday.

The areas that are likely to be affected by the release of Magat dam are municipalities of Ramon, San Mateo, Aurora, Cabatuan, Luna, Reina Mercedes, Burgos, Naguilian, and Gamu in the province of Isabela

While the release of Ambuklao and Binga dams are also expected to affect Barangays Dalupirip and Tinondan in Itogon, Benguet.

On Saturday afternoon, the Ipo Dam located in Norzagaray, Bulacan has also opened one gate at 0.5 meters as its elevation is already at 101.37 meters, slightly higher than its 101 meters normal high water level.

PAGASA advised residents in Barangay Matictic in Norzagaray that flooding is possible due to Ipo dam’s release.

A general flood advisory was issued by the local weather bureau among the regions of Cordillera Administrative Region, Ilocos, Cagayan Valley, Central Luzon, CALABARZON, MIMAROPA, Bicol, Western Visayas, Central Visayas, Eastern Visayas, and Zamboanga Peninsula.

PAGASA has also issued river basin warnings yesterday in Pasig-Marikina-Tullahan, Bicol, Pampanga, Cagayan, and Agno.

In a press briefing at the PAGASA Headquarters yesterday, hyrdologist Richard Orendain said a flooding episode occur within the Pasig-Marikina-Tullahan River Basin Saturday morning.

In Tullahan River, monitoring stations in Quirino, Quezon City; and Ugong Valenzuela are both in alarm levels as well as in Mindanao and People’s Park Stations in Quezon City located along San Juan River sub-basin, which means that the observed water level is already nearing the critical level.

In Mindanao and People’s Park Stations in Quezon City located along San Juan River sub-basin.

Meanwhile, in Pasig-Marikina River, both Sto. Nino Station and San Mateo-1 Station already reached their critical level of 17 meters and 20 meters, respectively.

Orendain said water levels in all reservoirs and river basins are expected to rise as rainfall is expected to pour before Ompong’s expected exit from the country on Saturday night.

PAGASA advised the public to remain alert on possible flooding and told those near rivers in critical levels to evacuate and watch out for upcoming advisories.