The Asian Development Bank said Monday it approved a $123.2-million loan for a new six-kilometer water tunnel connecting Angat Dam in Bulacan province to Metro Manila’s water supply.
The Manila-based multilateral lender said the funding for the water tunnel would reduce the risk of shortage, as demand for water rose in tandem with the growth of Metro Manila’s population.
“The Angat transmission system provides more than 95 percent of Manila’s water but its existing tunnels are up to 75 years old and in poor condition, leaving the metropolitan area highly vulnerable to serious supply disruptions,” said Paul van Klaveren, senior urban development specialist with ADB’s Southeast Asia Department.
“This assistance will allow the Metropolitan Waterworks and Sewerage System to build a fourth tunnel, clearing the way for it to upgrade and modernize its other existing tunnels and aqueducts to maximize and strengthen supplies,” Klaveren said.
MWSS is a government-owned corporation, supplying raw water for Manila, with two private companies, Maynilad Water Services Inc. and Manila Water Co. Inc., holding distribution concessions
ADB said demand for water grew strongly to around 40 cubic meters a second, with the concessionaires largely able to meet demand in the past by sharply reducing non-revenue water, or water that is produced but does not reach the customer due to system faults.
MWSS plans to develop a major new water source, which is expected to be operational after 2021. Before the completion of the new water source, there is an urgent need to rehabilitate the Angat system to avert a potential supply breakdown. MWSS is carrying out improvements including the construction of a new aqueduct.
“The main components of the Angat transmission line are as old as 50 years, in poor condition, and not in compliance with structural and seismic requirements, risking the partial interruption of Metro Manila’s water supply,” ADB said.
“The benefits of this aqueduct can only be fully achieved if a new tunnel is built to provide it with raw water,” ADB said.
The planned tunnel will be over six-kilometers long with an internal span of about four meters, 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.
The multilateral lender will also provide capacity building support 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,” the bank said.
Demand for Angat water is about 4.48 million cubic meters per day, which slightly decreased from 2010 to 2015, as a result from the very successful NRW reduction programs of the concessionaires.
ADB, however, said demand would increase rapidly from 2015, due to expected water supply area expansion and population growth. The demand is expected to increase by 38 percent by 2025 to 6.16 million m3/day.
ADB has extended finance for 10 Metro Manila water projects, including three for the Angat supply system since 1974.