The Asian Development Bank (ADB) has approved a $123.3 million loan for a new water tunnel to help modernise Manila’s water supply, reducing the risk of shortages as demand for water rises in tandem with the city’s booming population.
According to Paul van Klaveren, senior urban development specialist with ADB’s Southeast Asia Department: “The Angat transmission system provides more than 95 per cent of Manila’s water supply but its existing tunnels are up to 75 years old and in poor condition, leaving the metropolitan area highly vulnerable to serious supply disruptions.
“This assistance will allow the Metropolitan Waterworks and Sewerage System (MWSS) to build a fourth tunnel, clearing the way for it to upgrade and modernise its other existing tunnels and aqueducts to maximise and strengthen supplies.”
The MWSS is a government-owned corporation, supplying raw water for Manila, with two private companies holding distribution concessions. Demand for water has grown strongly to around 40 cubic meters a second (about 1,413 cu ft/ sec), with the concessionaires largely able to meet demand in the past by sharply reducing nonrevenue water, or water that is produced but does not reach the customer due to system faults. However, with demand still increasing, the MWSS is planning to develop a major new water source, which is expected to be operational after 2021.

In the interim, there is an urgent need to rehabilitate the Angat system to avert a potential supply breakdown, and the MWSS has been carrying out improvements including the construction of a new aqueduct. The benefits of this aqueduct can only be fully achieved if a new tunnel is built to provide it with raw water.
The planned tunnel will be over six kilometers (3.7 mile) long with an internal span of about 4 meters (13 ft), an intake structure at the Ipo reservoir, and a new transition basin at Bigte, along with connecting infrastructure.
A key element will be structural measures to limit the impact of earthquakes and other hazards, as well as environmental degradation. Capacity building support will also be provided to improve the skills of MWSS staff so that they can meet their management responsibilities for securing raw water supplies for the concessionaires.
Ensuring security of water supplies is crucial for both the economic well-being of Manila and the health of its citizens.
Since 1974, ADB has extended finance for ten Metro Manila water projects, including three for the Angat transmission system. Privatisation of distribution has had significant benefits with the serviced population doubling since 1997, and 90 per cent of the population now having round-the-clock water access. The amount of nonrevenue water lost from Manila’s water supply has been cut from more than 60 per cent in 2002 to between 10 per cent and 40 per cent in 2015.
This article first appeared on the Asian Development Bank website and is reproduced here with its kind permission.
Related:
- ADB commits $123.3 million to improve Manila’s water supply (Business Insider)
- Marcos seeks review of water contracts (The Manila Times)
- Even without rains, Angat can supply water (Malaya Business Insight)

In 2017, ADB operations totalled $32.2 billion, including $11.9 billion in co-financing.

Latest posts by Asian Development Bank (see all)
- RRTS: Increasing inter-island trade in the Philippines through island hopping – June 22, 2020
- Bayan Bayanihan brings food and hope to the poorest of the poor – May 21, 2020
- COVID-19: the time to act on food security is now – May 10, 2020
- No handwashing for 1 in 5 Indonesians as COVID-19 runs wild – May 8, 2020