Special Project Report: Angat Water Utilization and Aqueduct Improvement Project (AWUAIP), Phase 2

The Angat Water Utilization and Aqueduct Improvement Project (AWUAIP) Phase II is part of the first completed infrastructure project under the WSLP. The PhP 5.3 billion project ensures the conveyance of raw water from Angat Dam to La Mesa Dam all the way to the water treatment plants in La Mesa and Balara by rehabilitating and repairing the leaking Aqueduct (AQ) No. 5. The estimated 394 million liters of water lost daily due to pipe leaks can now be used to augment water supply and availability, especially in expansion areas in Rizal,Cavite and Bulacan provinces.

Funded by the Chinese government thru the Preferential Buyer’s Credit Loan Agreement from the Export-Import Bank of China, the project was finished eight months ahead of construction schedule due to the use of efficient project management and advanced construction methodology. Based on the original plan, the target completion date was March 2013.

However, a fast-tracked implementation plan was contrived, which reset the target date six months in advance or a new target completion date of September 2012. As it turned out, the project was finished even ahead of the new target date of September and was inaugurated in July 2012.  The MWSS project team determined that the following factors largely contributed to the fast implementation of AWUAIP Phase 2:

 • The construction and use of a fabrication plant of 3.3 meter diameter steel pipe for the aqueduct (Package No.1) and the steel liners (Package No.2) for the 5,400-meter Aqueduct No. 5 rehabilitation. The plant was strategically positioned mid-way along the aqueduct route that facilitated the transport of materials to and from the worksites;

• Plant hydro-testing was used more than field hydro-testing that reduced time;

• Conversion of Tunnels 3, 4 & 5 to open-cut aqueducts, which enabled open excavation instead of the boring method of excavation that enabled ease in excavating works.

• Application of new technologies such as the collapsible steel forms in lieu of conventional wooden forms for the pouring of the final concrete lining of the tunnels;

• Increased manpower complement and increased number of equipment without additional costs, wherein the increase in manpower complement and number of equipment used was offset and balanced off by the decrease in implementation period; and

• Early start of mobilization activities that started in 17 March 2010, which was even before the official contract commencement date of 9 May 2010.

This project is most significant to MWSS as it symbolizes the new management of MWSS.  No less than President Aquino took notice of the positive changes and major reforms at the MWSS. During the July 2012 inauguration ceremonies of the AWUAIP Phase II, President Aquino mentioned in his speech:

Hindi lang ninyo pinapaunlad ang kapasidad ng MWSS, ibinalik din ninyo ang integridad sa inyong tanggapan. Noong 2010, 34 million pesos and nalugi sa inyong tanggapan, pero dahil sa maigting na pagpapatupad ng mga reporma, umabot ng 330 million pesos and kita ng MWSS nitong 2011. Nabayaran na rin po ninyo ng kabuuang 236 million pesos para sa mahigit isang libong retirees noong nakaraang taon. 150 million pesos ang ibinahagi ninyong dibidendo sa gobyerno na magsisilbing pondo sa ating serbisyo-publiko.”

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The AWUAIP Phase 2 Project, considered to be among the flagship activities of MWSS, is a vital key to securing continuous water supply to millions of people in Metro Manila.  It seeks to abate the continuing water loss, in the form of leakage in major tunnels, of an estimated 600 MLD, or one-sixth of the total output of Angat Dam. As is publicly known, the Angat Dam provides 97% of the water needs of residents of Metro Manila and Rizal and some cities and municipalities of Cavite.


Name of Project Angat Water Utilization and Aqueduct Improvement Project (AWUAIP) Phase 2
Location Norzagaray, Bulacan to La Mesa Dam, Novaliches, Quezon City
Notice to Proceed March 17, 2010
Completion Date March 16, 2013
Contract Cost (Php) Package 1 – Aqueduct & Tunnel Construction (9.9 km)


  Package 2 – Aqueduct No.5 Rehabilitation (5.5 km)


  Package 3 (Interconnection Works)


  Total Cost


Implementing  Office Metropolitan Waterworks & Sewerage SystemIn Cooperation with MWSI and MWCI
Contractor China International Water and Electric Company
Construction Consultant Engineering Development Corporation of the Philippines with TCGI and WCI
Source of Funds Preferential Buyer’s Credit of China Export-Import Bank


“…a fast track implementation plan was put in motion by the new MWSS management, which significantly moved the target completion date forward to July 2012 and resulted in substantial savings for the national government.”


Raw water from Angat Reservoir is conveyed through a system of tunnels and aqueducts (each with a full length of approximately 15.4 kilometers) to water treatment plants and, eventually, to 15 million consumers in Metro Manila. The ages of the tunnels and aqueducts vary, with the most recent construction being that of Aqueduct No. 5 (AQ-5), which was completed in 1992.  AQ-5 was designed to carry 2,000 MLD, or half of the total water supply for Metro Manila.


Flow measurements conducted in June 2005 indicated that AQ-5 had a significant amount of leakage, estimated at 391 to 609 MLD. The ensuing emergency leakage repair excavations revealed major leaks in the first 5.5 kilometers of AQ-5.

In view of the deteriorated condition of AQ-5 and in order to reduce the risk to practically half of Manila’s water supply, MWSS and the two concessionaires decided to construct a new aqueduct (AQ-6), for implementation in two phases. The first phase, which consists of a total length of 5.5 kilometers and was completed in February 2006, serves as a by-pass of the most deteriorated section of AQ-5. Construction was financed by the National Government.

The second phase involves the construction of the remaining 9.9-kilometer section of AQ-6 and is financed through a Preferential Buyer’s Credit of China Export-Import Bank. This phase also includes the rehabilitation of the first 5.5-kilometer section of AQ-5 and the interconnection of the aqueducts.

The project is a concrete manifestation of MWSS’s firm commitment to ensure water supply security to Metro Manila. As such, its primary goal is to safeguard the integrity of raw water conveyance from Ipo Dam to the La Mesa portals.

Once completed, the project is expected to serve the needs of an additional 6 million people. By the first quarter of 2013, AQ-6 is envisioned to drastically reduce the risk of water shortage, 50% of its total output being intended for Metro Manila.

Additional beneficiaries are the people of Caloocan City and San Jose Del Monte City, Bulacan. The project is expected to spur development and ensure continuous supply of water in these areas.

Based on the original plan, completion date of the project was targeted for March 2013. However, upon the continuous prodding of the new MWSS management, a fast track implementation plan was put in motion which significantly moved the target completion date forward to September 2012. From all indications, the project is right on track with the advanced completion date.


Enhanced implementation is largely attributed to the following factors:

  1. Strategic repositioning of the fabrication plant of the steel pipes and steel liners
  2. Performance of plant hydrotesting in lieu of field hydrotesting
  3. Conversion of Tunnels 3, 4 & 5 to open cut aqueducts
  4. Application of new technologies, such as using collapsible steel forms in final concrete lining of tunnels
  5. Increased manpower complement
  6. Increased number of equipment
  7. Early start of mobilization activities