The Department of Public Works and Highways (DPWH) has provided engineering solutions to stabilize both banks of Pasig-Potrero River and preserve the existing Mancatian Bridge in Porac, Pampanga.
DPWH Secretary Mark A. Villar said that countermeasure projects are on-going that will restrain riverbed degradation and ensure safety by preventing the pile foundations of Mancatian Bridge along Angeles-Porac Road from being further exposed.
Secretary Villar added that protecting the bridge is vital in keeping Barangay Mancatian connected with the rest of Porac town.
In his report to Secretary Villar, Undersecretary for Unified Project Management Office (UPMO) Operations Emil K. Sadain said that the construction of dikes and groundsills with stepped dams at downstream of Mancatian Bridge will stabilize the riverbed and reinforce the structural integrity of the 270 meter bridge and protect from threat of flood inundation and damaged to properties.
Undersecretary Sadain together with Project Manager Isabelita Manalo recently inspected the on-going structures implemented by UPMO Flood Control Management Cluster under the Pinatubo Hazard Urgent Mitigation Project.
Designed to fix the riverbed elevation and mitigate scouring by forces of turbulent flow during floods, construction of groundsill 1 including left and right dike is at 80 percent while groundsill 2 is at 91 percent. Another groundsill project started on February 2021 is now at 21 percent.
To maintain river channel capacity and stability, a 136 lineal meter dike along groundsills across Pasig Potrero River at the downstream of Mancatian Bridge is being built and is now 96 percent completed. Also, retrofitting works of dike both sides of Mancatian Bridge and other related facilities of the bridge are also on-going at 80 percent which is more than 20 percent ahead of schedule.
These protective engineering works are based on 2019 study carried out by experts from the Japan International Cooperation Agency (JICA) as structural measures to mitigate damage to highly susceptible foundation of Mancatian Bridge where regular flow of lahar and water from eastern slope of Mt. Pinatubo brought down through the Pasig-Potrero River, said Undersecretary Sadain.
Built on 9 span prestressed concrete deck girder with 1.20 meter diameter bored piles, Mancatian Bridge was completed in 2004 under the Pinatubo Hazard Urgent Mitigation Project Phase 2 funded Japan Bank for International Cooperation and has withstand several earthquakes and lahar onslaught for nearly two (2) decades.
The 9.54-meter wide concrete bridge replaced the old Mancatian Bridge destroyed by the initial lahar onslaught in 1991 and the temporary steel bridge constructed in 1995 that was also washed out during one of the most disastrous lahar events of 1997.