Based on information on the website of the Metropolitan Waterworks and Sewerage System (MWSS), the main sources of Metro Manila’s water supply are the Angat, Ipo, and La Mesa Dams. And, water from these dams go to the La Mesa and Balara Treatment Plants and are turned from raw water to clean and potable water.
Raw water from Angat, the major supply source for the metropolis, goes through about 22 kilometers of pipes to La Mesa Dam and Treatment Plant (about 60% of total volume), and then another 6.8 kilometers of pipes to the Balara Treatment Plan (the remaining 40%). La Mesa can process 2,400 MLD (million liters per day) of raw water, while Balara can treat another 1,600 MLD, to both supply more than “six million people” in the metropolis.
In a column about two years ago to date, I already raised the alarm about Metro Manila sourcing most of its potable water from the Angat reservoir system, which also reportedly sits on the West Valley Fault going through Bulacan. “In case of a major earthquake in the area, or drought, then we lose our water. In fact, unless new supply comes on stream, shortage is already expected by 2020,” I wrote back then.
In a 2013 paper, the Asian Development Bank (ADB) noted that demand for reliable potable water in Metro Manila has increased considerably since 1997, with the aggressive extension of the distribution system by the two water concessionaires: Maynilad Water, and Manila Water.
It added that the estimated number of people served by MWSS roughly 22 years ago or in 1997 was about 6.5 million or 60% of Metro Manila’s population. But, by around five years ago, or 2013, the number of people served with continuous water supply was already close to 13 million.
So, one can already notice the mismatch if the La Mesa and Balara treatment plants can process potable water for only about six million people. Metro Manila’s daytime population is estimated at 15 million, while the number of residents is placed at around 12.8 million, based on a 2015 census. By 2020, it is predicted that Metro Manila will have a population of 20 million, far more than what MWSS can service with drinking water.
Obviously, supply is now the big issue. The Balara treatment plant, which supplies Manila Water, can process 1,600 MLD, but demand in its distribution area is reportedly nearly 1,800 MLD already. At the same time, La Mesa Dam’s water level is so low it has reportedly gone below the level of the aqueduct that brings water to the Balara plant.
Weather is an obvious culprit, and perhaps mismanagement of water resources. With a long, hot summer expected, coming months are forecast to be drier. Water supply will go down even further, and more rotating supply cuts can be expected until the rains come.
Unlike rice, and other food, it is highly unlikely for us to “import” potable water. Although, this is not impossible. It is a viable option. Singapore has been “importing” water from Malaysia for almost 60 years now. It gets water from the Linggiu Reservoir, which is fed by the Johor River. Singapore first signed a water supply agreement with Malaysia in 1962, and then renewed this for another 50 years in 2012.
But a big lesson can be learned from what Singapore has been doing meantime, working diligently to ensure self-sufficiency before the new Malaysia supply deal lapses in 2062. This was after noting that the Linggiu Reservoir has been drying up, and is not likely to continue to meet the future demand for water in Singapore.
Almost two years ago to date, I wrote about how Singapore has improved on its “Four National Taps” to boost water supply from (1) Local Catchment, (2) Imported Water, (3) highly-purified reclaimed water known as NEWater, and (4) Desalinated Water. Projects (1), (3) and (4) are all worth considering locally, I believe.
Since 2011, according to Singapore’s national water agency, the country’s “water catchment area has been increased from half to two-thirds of Singapore’s [entire] land surface.” The long-term goal is to increase the water catchment area “from two-thirds to 90% of Singapore’s land area.” And most of this, the agency said, will not necessarily be natural forests or watersheds but will be made up of “unprotected catchments which are land where development is allowed… for residential, commercial and non-pollutive industrial purposes.”
And then there is Singapore’s “NEWater”, or producing “high-grade reclaimed water produced from treated ‘used’ water that is further purified using advanced membrane technologies and ultra-violet disinfection, hence making it ultra-clean and safe to drink.” NEWater now supplies 40% of Singapore’s water needs. This is seen to increase to 55% by 2060.
But 2022, Singapore will also complete its “Deep Tunnel Sewerage System” or DTSS, a 48-kilometer “used water superhighway” to bring “used water” to water reclamation plants. Used water is then either treated and purified into reclaimed water or NEWater, or discharged into the sea as clean water.
Moreover, Singapore has put up two desalination plants that produce 100 million gallons daily (roughly 400 MLD) or about 25% of current water demand. A third desalination plant was to be completed in 2017, and a fourth by 2020. With all these plants, desalinated water was expected to supply as much as 30% of Singapore’s water needs by 2060.
Singapore, a hot and humid country like the Philippines, has also been conserving water. Its national water agency noted that despite rising population and demand, per capita domestic water consumption actually dropped to 151 liters per day from 165 liters per day in 2003. The government is targeting to further cut this to 147 liters by 2020, and 140 liters by 2030.
The “Millennium Drought” in Australia from 1996 to 2006, and the continuation of hot-dry conditions until 2009, also prompted the Aussies to build six major seawater desalination plants to provide water to major cities, and resulted to changes in the management of water in catchment basins or areas.
Australia also went into double piping, to allow for greywater recycling. Double piping refers to using a different set of pipes to supply and drain drinking and potable water, and sewage and toilet water. This allowed for greywater recycling. Greywater or sullage is all wastewater generated in households or office buildings without fecal contamination — or all wastewater except those from toilets. Sources of greywater include, sinks, showers, baths, clothes washing machines or dish washers. Greywater can be treated and reused onsite for toilet flushing, landscape or crop irrigation and non-potable uses. They can also be used for fighting fire.
It is not too late for MWSS, and Maynilad and Manila Water, to go beyond waiting for the rainy season and to look into various options to remedy the water shortage. While there are ongoing water supply projects, we should already adopt modes that go beyond harnessing natural water supplies. Singapore, Australia and many other countries around the world can share some of the best practices we can consider.
Marvin Tort is a former managing editor of BusinessWorld, and a former chairman of the Philippines Press Council