Not many people know that there are 17 freshwater reservoirs in Singapore, or that we have a large reservoir across the Causeway in Johor.
Constructed by the PUB following a 1990 treaty supplementary to Singapore's 1962 Water Agreement with Malaysia, the Linggiu Reservoir dwarfs them all. In fact, with an 18km girth and 55 sq km in area, Linggiu is five times larger than all of Singapore's other reservoirs combined.
RESERVOIR STOCK RUNNING LOW
Two weeks ago, my boss, Minister for the Environment and Water Resources Masagos Zulkifli, made the bumpy trek to Linggiu.
He did so with one aim: to tell the Singaporean public that - because of persistent dry weather - Linggiu Reservoir is more than half empty and that, while water supply in Singapore remains steady and resilient, the dry weather may eventually also affect us.
As I write, several parts of Johor Baru are well into the fourth month of water rationing. Many of Johor's own reservoirs are at critically low levels and a "one-day-on- two-days-off" scheduled water supply has been in operation since early August.
The water authority there has asked PUB to augment its supply during this period with an additional five million gallons a day (mgd) of potable water from our treatment plant in Johor, which we readily agreed to do.
Imported water - which can meet half of Singapore's daily demand for drinking water - is under threat and steadily depleting, but the taps continue to flow for consumers here.
This is an unappreciated blessing. For sure, this outcome is not in any way due to good fortune. It stems from long and careful planning, and conscientious implementation by PUB and other parts of the Government.
Singapore's continued ability to ensure water security and sustainability guarantees our national survival and economic prosperity. This was the case at Independence and it remains so now, when Singapore has turned 50.
Singapore's current demand for water is approximately 400 mgd, roughly 730 Olympic-size pools full of the life-giving stuff, with each person using an average of 150 litres a day.
As industry and commerce grow and our population increases, the demand for water can only rise. We expect total demand to double by 2061, to 800 mgd. This is also around the time our 99-year water agreement with Malaysia will end.
By 2030, 15 years from now, total demand would have reached 560 mgd, or a third more than today's.
This is water that we do not have now - water that we will need to find and treat.
There is just not enough space in Singapore to collect and store all the water that we need. Although right on the Equator and in the tropics, Singapore is actually a severely water-challenged country. We spend a lot of time and devote a lot of resources in planning for the future. PUB always builds ahead of demand.
Construction of Singapore's third desalination plant will soon commence. Plans for a fourth have just been announced. And you can be sure that we are busy working on the one after that.
Water security is a matter of life and death for us in Singapore. Our existence as a sovereign nation is directly contingent on enduring water security. The late Mr Lee Kuan Yew, Singapore's first Prime Minister, recognised this fact from day one, and worked tirelessly throughout his life to secure our water future. He once said: "Water dominated every other policy. Every other policy had to bend at the knees for water survival."
Singapore's water strategy comes in three parts. First of all, we have to maximise our own yield. So we strive to collect every drop of rain that falls here. This means turning as much of Singapore as possible into a water catchment, and keeping our drains, canals and waterways pristine.
Second, we have to think of water as an endlessly reusable resource. In our minds, the H2O molecule is never lost. Water can always be reclaimed and re-treated so that it can be drunk again.
PUB is a world leader in this. Today, we are able to turn wastewater into sweet water for very little money. We reclaim every drop of sewage and turn much of it into drinking water again.
And third, because Singapore is surrounded by sea, we turn seawater into drinking water. When membrane separation technology made desalination economically viable, PUB adopted it with great zeal. And we continue to research better desalination technology to find less expensive ways of desalting water.
Our plan, in the long run, is for fully 80 per cent of Singapore's water needs to be met by desalinated and recycled water.
TECHNOLOGY, INNOVATION, INGENUITY
The future of water security in Singapore may lie with desalination and reuse, but we also know that if we just do more of the same, the next drop of water will always be more expensive to collect, to treat and to deliver. So, PUB is always looking for new ways of doing things, new innovations that will let us produce water cheaper, and in an easier way.
Because the heavens do not give us enough water or the space to keep it, we have looked to clever science and high technology, and to human ingenuity, for improvements... It will be technology and innovation that will allow us to collect and clean our wastewater, and continue to keep our soil, rivers, lakes and seas clean and hospitable.
We are crystal clear about achieving three outcomes for research and innovation in the water sector: to increase water resources; lower the cost of production; and improve security and system resilience.
In order to achieve and sustain these outcomes, PUB has invested and continues to invest a lot of money in water-related scientific research, in nurturing human talent in water technology and engineering, and in actively developing a thriving and globally competitive water industry.
Water R&D is an exciting and fast-moving area. The cutting-edge science that PUB is supporting in research laboratories all over Singapore suggests that we are on the cusp of realising some truly game-changing technologies. Let me provide a few examples.
Desalination may be weather- resistant, but it is energy- intensive and a costly means of making seawater drinkable. Working with collaborators, PUB is ready to demonstrate electro-deionisation - the use of a new separation technology - as a far more energy-efficient way of taking salt out of seawater.
But why stop there? Mother Nature, as always, does it best. Mangrove and fish in the sea need fresh water too, and they are able to remove excess salt with minimal effort. Biomimicry offers great promise and is another area of research that we have devoted considerable resources to.
PUB engineers who have made wastewater treatment their life work will tell you that there is "gold" in sewage. Sludge, an inevitable by-product of sewage treatment, is concentrated organic material.
Energy can be readily recovered from sewage sludge in the form of methane gas. Because sludge management technology is advancing by the day, modern sewage treatment facilities are fast becoming waste-to-energy plants. PUB's planned Tuas Water Reclamation Plant will be just that.
To be developed jointly with the National Environment Agency's Integrated Waste Management Facility, this combined unit will be a world first, bringing unprecedented synergies in terms of land use, energy savings and operational efficiency.
Leaky pipes are enemy No. 1 for water network engineers. It is quite senseless to expend effort and energy in making water potable only to lose it through leaks in the water transmission network.
Losses because of leaks are a perennial challenge for water utilities the world over, and the water systems in some countries can lose as much as half of their production due to leaks. Despite fastidious attention to finding and plugging pipe leaks here, keeping our losses at the current 5 per cent is a daily challenge for our engineers and technicians.
Again, technology offers a solution. PUB is busy fitting out our extensive water conveyance network, most of which is underground, with sophisticated pressure and acoustic sensors. These not only detect pipeline ruptures, but careful study of sensor data will even help us predict imminent leaks before they happen, allowing us to do pre-emptive repairs.
Despite severely limiting geographic constraints, today's Singapore is not short of water.
As long as we at PUB continue to be smart and clear-eyed about our nation's water situation, and do our work well, there should always be enough water. This is possible only because we have used our imagination, researching and testing continuously, and have exploited technology to overcome our water challenges.
In this way, we have turned disadvantage into strength, and seemingly insurmountable vulnerability into endless opportunity.
This article was first published on November 27, 2015.
Get a copy of The Straits Times or go to straitstimes.com for more stories.