MANILA, Philippines — The commissioning of Tunnel No. 4 , a tunnel from Ipo Dam to Bigte, in Norzagaray, Bulacan, began Monday after the successful completion of all components of the Angat Water Transmission Improvement Project (AWTIP), according to the Metropolitan Waterworks and Sewerage System (MWSS).
In a statement, MWSS said the completion of AWTIP marks a milestone in the agency’s promise of water security for Metro Manila.
“The centerpiece of AWTIP is a 6.3 kilometers tunnel with a finished, internal span of 4 meters, designed to accommodate 19 cubic meters per second raw water from Angat Dam,” said MWSS.
“The tunnel excavation used a modern mechanized double blade tunnel boring technology, at below ground surface depth of 200 meters. The tunnel is lined with precast concrete with steel reinforcement to ensure structural integrity and that raw water flows in the long term,” it added.
Construction of the P3.29 billion tunnel project started in June 2016 and was completed in June this year, three months ahead of the original completion date in September.
AWTIP is a critical component of the water security program of the MWSS as it tries to reduce the risk of partial or total disruption of water supply in Metro Manila.
MWSS Administrator Emmanuel Salamat also visited the project site earlier on Monday.
“I am very pleased to see the completion of Tunnel 4 as it now paves the way for the rehabilitation of the transmission system’s main components that are as old 75 years, in poor condition, and most likely not in compliance with current structural and seismic requirements. These factors could seriously interrupt Metro Manila’s water supply, ” he said.
The completion of Tunnel 4 is a joint effort of the Philippine government, with the MWSS as executing agency, and the Asian Development Bank.
“MWSS is grateful to ADB for investing in water projects that secure additional bulk raw water transmission to consumers and alleviate the growing demand for water in the service area,” said MWSS.