More Luzon waterways may oveflow from enhanced monsoon rain

MANILA – Waterways in Calabarzon (Cavite, Laguna, Batangas, Rizal, Quezon) areas and east-lying Region II (Cagayan Valley) are already at risk for overflowing due to the prevailing southwest monsoon or “habagat” which was enhanced by Typhoon Fabian (international name In-Fa).

Major Calabarzon waterways that may be affected are Quezon province’s Upper Umiray, Lower Bolbok (Lawaya), Malaking-Ilog, Iyam, Macalelon, Catanauan, Silongin Lagda, Pagsanjan, Yabahaan, Bigol, Guinhalinan, Vinas, Calauag, Pandanan, Sta. Lucia, Lugan Malaybalay, Maapon, Bucal (Lalangan), Lakayat, Tignoan, Agos, Anibawan (Polilio Island) and Upper Kilbay – Catabangan;

Cavite province’s Laboc (Balsahan), Cañas, Ylang-ylang and Imus; Laguna province’s Pagsanjan, Pila-Sta. Cruz, San Juan and San Cristobal; Batangas province’s Lian, Banabang-Molino, Pansipit, Kapumpong, Rosario-Lobo and Upper Bolbok (Lawaya), as well as Rizal province’s Upper Marikina and Kaliwa, according to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) on Thursday.

In Cagayan Valley, major waterways likely to be affected are Cagayan province’s Linao, Lower Abulug, Lower Pamplona, Cabicungan, Aunugay, Baua, Palawig and Taboan as well as all rivers and respective tributaries in Nueva Vizcaya province.

“Small tributaries of those major waterways may overflow also,” said PAGASA hydrologist Sheila Schneider.

Even rainfall of short duration can easily fill up such tributaries and already cause these channels to overflow, she noted.

Communities concerned must prepare accordingly as overflowing water of major waterways and respective tributaries can spill into and possibly flood surroundings, she noted.

Earlier, PAGASA warned about the possible overflow of water in western Luzon’s waterways.

In its 5 a.m. tropical cyclone bulletin on Thursday, PAGASA located “Fabian” at 530 km northeast of Itbayat municipality in extreme northern Luzon’s Batanes province.

“Fabian” is moving west-southwestwards at 10 kph, packing maximum sustained winds of 150 kph near its center and gustiness of up to 185 kph.

PAGASA expects “Fabian” to be outside the Philippine Area of Responsibility (PAR) by Saturday (July 24).

“While moving away from the country, however, ‘Fabian’ will still enhance habagat so people must prepare accordingly,” said PAGASA weather forecaster Ariel Roxas. 

He said even after “Fabian” dissipates, the southwest monsoon will likely still affect the country although to a lesser degree — bringing cloudiness and scattered rain showers next week.