Manila Water's TBM-driven Novaliches-Balara Aqueduct 4 project nears completion

Aug 16, 2021

THE Metropolitan Waterworks and Sewerage System (MWSS) celebrates Manila Water's milestone in its landmark Novaliches-Balara Aqueduct 4 (NBAQ4) project as the tunnel-boring machine (TBM) being utilized for the project has already broken through at the La Mesa Reservoir, more than seven kilometers away from its entry shaft at Balara in Quezon City. The P5.5B NBAQ4 project, one of the largest MWSS-led water supply infrastructure projects undertaken by Manila Water, entails the construction of a fourth aqueduct from the La Mesa Reservoir to the Balara Treatment Plants (BTP) 1 and 2 to improve the reliability and security of the raw water transmission system.

In a simple ceremony held last August 14 to celebrate this milestone, workers and guests witnessed the exposure of the TBM cutter head from the soft concrete at the exit shaft. The tunnel-boring machine technology, used for the first time in Metro Manila for this project, has been laying the 7.30-kilometer long and 3.10-meter diameter NBAQ4 underneath Commonwealth Avenue, without impact to traffic since its launch on January 28, 2020. With the pipelaying complete, the TBM named "Dalisay" and its accessories will now be dismantled and the construction of intake tower, outlet tower, and downstream network system will now commence. The project is expected to be completed by June 2022. Manila Water's partners in this project are Arup as the project management consultant; and Novabala joint venture, the project's design and build contractor composed of CMC di Ravenna (Italy), First Balfour, Inc. (Philippines), and Chun Wo Engineering (Hong Kong).

MWSS Board of Trustees Chairman and OIC Administrator Gen. Reynaldo Velasco (Ret.) said that this flagship project of Manila Water is part of the agency's water security program under the current administration.

"Part of the agency's landmark achievements is coming up with interim and long-term water source projects to approximate at least 4,000 million liters per day (MLD) in the next 10 or 25 or, hopefully, 50 years," he said.

Noting that the three existing aqueducts, built in 1929, 1956, and 1968 respectively, are already nearing, if not already exceeding, the service life of 50 years for concrete structures, Velasco cited the urgent need of assessment and rehabilitation even as he commended Manila Water for the completion of this important water security component flagship project. The existing aqueduct system continuously transmits 1,600 million liters per day (MLD) of raw water to BTP.

The NBAQ4 project shall provide a new aqueduct to enable the sequential temporary service suspension of the existing aqueducts for inspection, assessment, and subsequent rehabilitation to help ensure continuous water supply for more than 7 million population served in the East Zone. The NBAQ4 system is composed of a new intake facility at La Mesa, a 1,000-MLD underground aqueduct, and an outlet facility at BTP. Upon completion, the project will also provide emergency redundancy in the event of a failure in any of the existing aqueducts.