Digitalising water: The smart way to save

 Water – specifically, the lack of the stuff – occupies a special place in the Singaporean consciousness. We simply do not have enough space to collect and store all of the rainwater that we will need for later consumption. More than half of Singapore’s daily demand has to be imported from Malaysia, by way of a 99-year water agreement.

Our water situation compels us to turn to expensive manufactured Newater and even dearer desalinated seawater in order to quench new thirst. Indeed, the enduring sustainability and security of Singapore’s water supply present no less than an existential challenge for our country. This challenge can be made lighter through conscientious conservation.


Smart meters that help people track their water usage can reduce consumption

National water agency PUB is Singapore’s champion for water conservation. We are the ones constantly badgering the consumer to save water, to use less, and to buy only water-efficient appliances.


Most recently, we reported that the daily domestic per capita water consumption in Singapore reduced sharply by five litres, from 148 litres in 2016 to the current 143 litres. This reduction, of course, coincided with the first round of water price increases last year. In the popular imagination, this decrease has to be entirely due to the price increase! I would not go so far, but will concede that pricing was of focal importance.

The truth is that we do not yet know for sure. Because other than higher prices, there are two other moving parts: first, last year was wetter than normal (water consumption correlates inversely with rainfall); and second, the average efficiency of water appliances in Singapore homes continues to improve. More research and analysis are required before we can definitively parcel out the independent effects of each.

Anyhow, mechanical efficiency, wetter weather and more expensive water conspired to bring down per capita water consumption by more than 3 per cent last year. This is very encouraging, but still nowhere compared with the 100 litres/person/day being reported in Europe.


Just look at Denmark, which perhaps offers the most instructive example for Singapore. Almost exactly the same number of people call Denmark and Singapore home. Both are developed high-income jurisdictions with large sophisticated water systems that produce wholly potable tap water.

However, per capita household water use in Denmark was already 106 litres/day in 2015. By itself, this is a pretty good number, one which we are envious of.

But what really impresses is that daily consumption in Denmark declined 31 litres – from 137 in 1994 to 106 litres in 2015 – in just two decades – a whopping 23 per cent drop.

The drop was not brought about by any outrageous or extreme measure. Instead, as in Singapore, the reductions in Denmark were achieved through water-saving equipment and public campaigns, accompanied by economically efficient pricing.

The average Dane pays about €8.50 (S$13.60) per cubic metre of tap water, compared with the $2.70 that Singaporeans do.

To be clear, our aim is not to match the high Danish price for water, but to equal their attitude towards conservation. Doubtlessly, the average Danish consumer is far more environmentally responsible than his Singaporean cousin, and absolutely understands that water wasted is water lost.

Every one of us can, should and must use less water. Doing so is entirely feasible and does not require giving up modern-day comforts, compromising personal or public hygiene, or sacrificing commercial profitability. But it does require enlightened thinking, imagination, determination and conscious effort.

Personally, I believe 100 litres a day is achievable in Singapore, and should not be bothersome or inconvenient. But it will require a real behavioural change in the way every one of us uses water at home.

What would be required is that we all have to become smarter users of water. And we can become smarter only if we have more information and can do better sense-making every time we decide to turn that water tap.


Imagine that you are driving a car that has neither a speedometer nor a fuel gauge. Sounds ridiculous? Yet that is essentially the situation domestic water users find themselves in today.

The water meter outside every Singaporean home is the dumbest, albeit highly accurate, of sensors. It does not even require electrical power to work. Inside every plain-vanilla water meter is an impeller that rotates as water flows through it, the revolutions of which are subsequently converted into volumetric readings in a numerical counter.

To keep track of water consumption, the consumer needs to physically see the meter dial, make a record of the counter reading, and then return and repeat the same at a later chosen time. The difference between consecutive readings would be what was consumed in the intervening period. As physical verification of meter readings is cumbersome and costly, it is done infrequently. For billing purposes, water meters in Singapore are read every other month. Any more often would make it uneconomical.

Our challenge in PUB is to give our customers the water equivalent of the speedometer and fuel gauge, and so empower them to become smarter users of water.

The digital water meter is just such a thing. Battery and wireless technology, together with cloud computing, have improved to such an extent that a computer-enabled water meter now costs no more than the brass block of old.

Yet, such a smart sensor that can measure, register and wirelessly transmit usage data to remote servers, which in turn calculate and analyse before informing the consumer almost instantaneously, promises to change the game entirely.


A recently concluded smart metering trial in Punggol proved this. People living in 500 HDB households, because they received timely usage information, were able to meaningfully adjust behaviour and become more efficient consumers, saving water and money in the process. Enabled by information on tap – something previously unavailable to end-consumers – we saw participants save as much as 5 per cent by the end of the short trial. Another recent tryout, this time with smart showers in homes that instantly count down the amount of water used up as one washes, produced much the same benefits.

These experiments have convinced PUB that the digitalisation and constant availability of water use information will help to change consumer behaviour, leading to significantly reduced consumption. They also confirm that our ambitious plan to digitalise Singapore’s entire water system is a worthy and worthwhile one.


Ultimately, a litre of water that is not required, and therefore not used, is a litre not produced. The consequent savings in energy, chemicals, man and material, plant and equipment are not just expenditure avoided, but also go towards reducing our collective carbon footprint. Producer or consumer, we both do the earth a favour by not having to make or use up that marginal litre of water.

When it comes to water, we should all strive to become minimalists. Less is more.

(By NG JOO HEE for the Straits Times, reproduced with permission from PUB)

• Ng Joo Hee is the chief executive of PUB, Singapore’s national water agency. He is one of the speakers at the Singapore International Water Week conference, held in conjunction with the World Cities Summit and CleanEnviro Summit taking place from July 8-12 at MBS Expo & Convention Centre.