Thursday, February 23, 2017

Revisiting rainwater harvesting in Singapore

Hi there,


I came across your blog when I was doing some research on rainwater harvesting systems (we are in the process of renovating an old inter-terrace house that that we just bought, and thought that this might be worth exploring).


I know that this is a question that you fielded a number of years ago (hopefully things have changed since then, as your answer then was that there wasn't much demand for this), but would you know what is available in the market in Singapore in terms of rainwater harvesting systems for domestic households (we are looking for a fairly straightforward above-ground system) and are there any that you recommend? 


Thank you,



Dear Felix,
Indeed, the rainwater harvesting (RWH) market appears to have developed in the past few years. I believe RWH is becoming more widely known and accepted in SG. That comes with a rise in demand for RWH and naturally, businesses will be built around servicing this demand.

I am actually happy to see this happening as it shows that people are becoming green not just in words but in action too. However, we also have to bear in mind that the current RWH solutions in the market are more geared towards a private house rather than a HDB flat. (On the other hand, RWH can be done at community level by e.g. HDB at Treelodge@Punggol in which the whole HDB estate is designed and built for RWH.)

Over the past years, I have come into contact with some of these businesses. A quick online search should yield the same results.
  1. Green Eco Harvesting
    A quick glance shows that it is offering tanks and filters for RWH
  2. Netatech
    It advertises construction of RWH system.
  3. Hydro
    It features tanks and filters for RWH.
As for your question, no, I have no preference for the above or any other vendors. But if you decide to go ahead to integrate a RWH system into your house, a few points to keep in mind...
  1. Does the vendor only sell you the tank & filter or does it include installation into your existing house structure?
  2. What kind of maintenance is needed for your RWH system? Does the vendor offer such a service or are you on your own after its installation? Obviously, the cost and frequency of maintenance should be taken in consideration when you make your decision to get a RWH system.
  3. Is your setup legal??? Legally speaking, the plans for your RWH setup have to be approved by PUB and NEA (if gutters are involved in RW collection). These plans are typically submitted by a QP/PE/architect to the authorities. Is the vendor doing these for you or are you expected to engage your own QP/PE/architect to do so? Finally, legal means additional costs so factor that in too!
Good luck!

Figure: using a zinc roof to collect rainwater (Water for Life, Hesperian Foundation)
Who says RWH has to be complicated? It has been and still is done simply and cheaply in developing countries. Mosquito breeding is a concern but not insurmountable with care and effort.

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