ST forum letter about reservoirs evaporating sounds silly, but it makes some sense. Here’s why.

There are some flaws in his argument, but he's not all wrong either.

By Guan Zhen Tan | March 13, 2017

Another day, another Singaporean writing a forum letter to The Straits Times.

Written by one Mak Ngow Chai, he is apparently concerned with water being lost from the reservoirs via evaporation.

The following is the entirety of his letter:

Prevent loss of reservoir water through evaporation

Given Singapore’s hot weather, much of our reservoirs’ water would be lost through evaporation.

If 50 per cent of the exposed surface areas can be covered with an impermeable floating material, the overall evaporation would be reduced by 50 per cent.

This would quite significantly cut the amount of water lost through the natural process of evaporation.

Surely, it cannot be that nobody has thought of this easy way of conserving the water in our reservoirs.

Mak Ngow Chai

To most people, it’s ridiculous. It sounds like Mak’s got something against the natural process of evaporation.

What makes the letter even more scathing is that the writer exclaims that stopping evaporation to conserve water is “easy.”

At this point, readers probably think he sounds like he’s channelling Homer Simpson’s father in this meme:

Meme via Know Your Meme
Meme via Know Your Meme


Like it or not, however, he’s not entirely coming from the land of make-believe. In fact, his points would have sounded a little more logical, if only he had elaborated on his argument with the following points:


1) Evaporation is actually a tangible threat to water sources — in other places, at least.

Evaporation is something that naturally happens and we can’t really do much to entirely stop the process.

The effect on water is, thus, pretty significant. Moshe Alamaro, an Israeli scientist working as a senior research scientist at MIT has discovered that especially in the western parts of the US, more water is evaporated, rather than remaining as usable water.


2) Yes, technology exists to prevent water from being evaporated.

Almaro has also proposed the possible use of a non-reactive chemical layer which prevents the evaporation of water by 75 percent, adapted from an idea in the 50s and 60s.

In 2015, the city of Los Angeles turned a reservoir into a massive ball pit blanket of balls floating on the surface, saving them about 300 million gallons of water, or approximately 1.13 billion litres. You might have seen this viral video going around:

Closer to home, in 2014, an article on Fast Company‘s Co.Exist wrote that Singapore is reportedly planning on covering its inland reservoirs with solar panels to harness renewable energy, and, you guessed it, prevent water from being lost to evaporation.

Thus, slowing down evaporation really isn’t that far-fetched an idea.

3) It’s a possible response to the water price hike

It’s likely that letter was a suggestion on how we can conserve more water for our usage without having to resort to building more plants and using more expensive methods to treat water.

In fact, Alamaro had also stated that preventing evaporation would also help keep costs down, as a result of maximising the water collected by existing reservoirs rather than building a new one, or relying on expensive water treatment technology.

Not convinced? Well, it’s true that even with research, Mak’s line of argument is not without a few issues:

Evaporation is necessary for the water cycle to occur

Which in turn, allows clouds to form and facilitates rain.

Evaporation also allows for some purification of the water to take place, so it isn’t necessarily the most unnecessary thing to happen to our water.

Furthermore, restricting evaporation may also increase the temperature of the water and the exchange of gases in the ecosystem, which might have serious effects.

This, coupled with the lack of extensive research on such long-term effects may mean it’s still relatively premature a concept.


The way we use our reservoirs are somewhat different

It’s also important to note that different countries will manage their water sources differently, and different water bodies are also exposed to varied weather and climate conditions.

This results in vast differences in rates of evaporation, which varies the urgency and need to slow down evaporation.

In LA’s case, they were experiencing bouts of severe drought around that time period, which intensified water scarcity around the region.

It’s also good to remember we also use much of our reservoirs for recreational purposes, for sports such as dragon boating and kayaking, so covering it with physical objects such as shade balls might be highly impractical, and not to mention unsightly for reservoir visitors.

Ultimately, Mak almost had a point, but he could have better substantiated his letter with more research. Or it may have been edited out before it was published, so no one knows for sure.


Top image adapted via Wikipedia Commons

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About Guan Zhen Tan

Guan Zhen is a serial doodler with multiple pens with her wherever she goes. She loves listening to Visual Kei bands, Jamiroquai and random songs from the future-funk genre.

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