MANILA, Philippines – The retrofitting of Angat Dam, which has failed international standards in terms of structural integrity, is now underway, a Metropolitan Waterworks and Sewerage System (MWSS) official said Tuesday.
MWSS Administrator Gerry Esquivel said the agency is set to sign a contract on October 19 with New Zealand-based environmental and engineering consultancy firm Tonkin & Taylor.
Esquivel said the proposal to retrofit the dam located in Norzagaray, Bulacan was approved last April by President Benigno Aquino III.
He said the project has an estimate value of P1.5 billion. Once the contract is signed, Esquivel said it will take 3 to 5 more months before the actual retrofitting begins.
“Inaprubahan ng presidente yan ng Abril, tapos nag-meeting kami ng PHIVOLCS [Philippine Institute of Volcanology and Seismology], NIA [National Irrigation Administration] at Napocor [National Power Corporation]. Gumawa kami ng TWG [technical working group] para i-assess ang dam. At itong October 19, pipirma kami ng Tonkin & Taylor,” he said in an interview on dzMM.
“Malalaman natin kung maglalagay kami ng buttress systems sa pinaka-pwet niya. Hindi pa maliwanag kung ano ang gagawin nila.”
Esquivel said the MWSS seeks not only to strengthen the dam against forces of nature, but to increase its capacity as well.
He said that MWSS is targeting to increase the dam’s spilling level from 210 meters to 215 meters.
He explained that this increase will translate to an additional 10 million cubic meters of water that the dam can hold.
Concerns about the safety of Angat dam was raised after a study by international experts revealed the poor state of its structural integrity and instrumentation.
PHIVOLCS said the dam, whose main dike is located 200 meters east of the West Valley fault line, is vulnerable to strong earthquakes.
The agency said the dam lacks lacks equipment such as a piezometer that can measure the movement of land where the structure was built, and accelerometers that measure the amount of water entering the structure.