CITY OF SAN FERNANDO – The massive P5-billion rehabilitation of the Angat Dam will start early in 2013 amid findings it lies on an earthquake-prone fault.
The Office of Civil Defense (OCD) here said the rehabilitation was ordered recently by Pres. Aquino amid indications of a growing number of earthquake occurrences in Asia, as well as in other parts of the world.
The OCD noted that the Angat Dam, located in Norzagaray in Bulacan, lies along the West Marikina Valley Fault where temblors normally occur, although the agency noted that the dam has remained intact so far.
The private firm Tonkin and Taylor was recently tasked by the Metropolitan Water Sewerage System (MWSS) to scrutinize the dam and it said that the dam would likely be safe for another 50 years, it nevertheless recommended rehabilitation as a measure for higher safety requirements.
Angat Dam was built in the 1960’s.
Liz Mungcal, chief of the Bulacan Provincial Disaster Risk Reduction Management Office (PDRRMO), said the P5-billion fund would be released in two financial packages.
The first package, costing about $71 million, would be for the rehabilitation of the reservoir dike which dams up waters from the Sierra Madre mountains. This structure measures 568 meters long and 550 meters deep.
Another $122.5 million would be for the construction of two more spillways on either side of the three existing spillways at the dam.
The spillways are 131 meters tall, and serve as a channel for waters being released from the reservoir.
The additional spillways are expected to be finished in 42 months or three years.
Angat Dam is the source of potable tap water to about 13 million folk in Metro Manila. Waters from this dam flow into the Ipo Dam, also located in Norzagaray, which in turn flows into the La Mesa Dam in the southern part of Quezon City.
From La Mesa Dam, water is processed at the Balara Filtration Plant of the MWSS which funnels water into Metro Manila households through Maynilad and Manila Waters.