MANILA - The dredging of Marikina River early this year prevented the backflow of water to its communities, an official said Sunday as the southwest monsoon continued to dampen parts of Luzon.
Government began the project in February following a series of storms last year that inundated the city.
The dredging increased the river's water velocity and capacity, said Dave David of the city's disaster risk reduction and management office.
"Dahil po d'yan, ang mga komunidad po namin, 'di na nagkakaroon ng backflow. Ito po ang epekto ng dredging na ginawa natin sa Marikina River at engineering works sa drainage networks in city," he told ABS-CBN's TeleRadyo.
(Because of this, there's no backflow in our communities. This is the effect of the dredging in Marikina River and engineering works in the city's drainage networks.)
There are no recorded floods in the city's streets, David added.
"Walang recorded na flood areas or streets, particularly sa low-lying streets. Pinili po ng mga kababayan namin magkaroon ng preemptive evacuation base sa recommendation ng pamahalang lungsod ng Marikina," he said.
(There are no recorded flooded areas or streets, particularly low-lying streets. Our residents chose preventive evacuation based on the local government's recommendation.)
He said only "surface flooding" occurred over the past few days, which subsides as the rain stops.
The river's water level is at 15.5 meters as of 4 a.m., prompting alert level 1 to be raised, according to David. Preemptive evacuation begins at alert level 2, when the river's water level is at 16 meters, he said.
Forced evacuation is implemented at alert level 3 or when the river's water level reaches 18 meters, he added.
David noted that rainfall at 2 a.m. Saturday was recorded at 134 millimeters in an hour, which is higher than during tropical storm Ondoy in 2009.
"Pero, kinaya po ng kapasidad ng ilog yung volume na yun. Indikasyon po yun na naging maganda po yung naging epekto ng dredging sa amin," he said.
(But that volume was absorbed by the river. That indicates the good effect of the dredging.)
David said the number of evacuees in Marikina due to the habagat reached a peak of around 15,000, staying in 29 centers. Some have been closed on Saturday as many decided to return home.
As of Sunday, the number has gone down to more than 9,000, he added.