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Rainwater Harvesting at the Meraki Tiny House

June 15, 2019

Installing an off-grid rainwater catchment system to water the tiny house with.

 

 

Now that the rainy season has begun, at least in my part of the world, it seems to be a good time to introduce the water system I have going on at the Meraki Tiny House. The house is located up on the hill, with no access to the public utility grid at this point in time, which means I cannot plug into the electricity grid or the public water ways that my neighbours down below are on.

 

Which is just fine, because I never intended to anyway. This house was always meant to be an off-grid structure that can sustain itself. To that end, a solar power system was installed to provide the house with electricity, and it has been running smoothly ever since. 

 

As for water - well, I didn’t have to try very hard. It literally falls all around me almost every other day. 

 

 

Why harvest rainwater?

 

Because it’s free! 

 

And in a tropical country such as Malaysia, there is an abundance of it (and with climate change, it only means that it’ll get wetter in the tropics). Where the Meraki Tiny House is situated, the average rainfall is about 3000 mm in a year. 

 

 

In fact, given that amount of water dropping down on us from the heavens above, it seems ridiculous to not capture any of it. 

 

 

Overall System

 

The system itself is pretty simple, and not much more sophisticated that simply collecting water in a barrel, to be honest.

 

 

Below is a walk through of the system:

 

Rain falls on my roof and slides down the sloped surface into the gutter...

 

 

 

The gutter carries the water to the pipes that will bring the water down into the storage tank...

 

 

 

The storage tank is hooked up to a water pump...

 

 

Source

 

 

The pump then shoves the water through a water filter...

 

 

 

Source

 

And clean water is piped up into the house, right up to the bathroom and kitchen sink.

 

 

 

 

The system thus far

 

Like the solar power system, the rainwater harvesting system has been working well enough for our occasional visits to, and sleepovers at, the house (remember, I am not living there full-time yet). We clean the house, take showers, make tea, and cook Maggi Mee without a single problem or case of diarrhoea (for now!). I have not run out of water, yet, and the tank is continuously full each time I visit.

 

In the future, however, especially when I am there a lot more frequently and permanently, I definitely plan to upgrade the system a bit. 

 

 

Additional elements

 

What I’ve described above is a very basic rainwater harvesting system that’s adequate for showering, cleaning and the occasional boiling and cooking.

 

You can get a bit more fancy by adding the following:

 

 

1. A First Flush Diverter

 

When the rain begins to fall, it cleans up my roof a bit by sweeping whatever is on it with water. This means whatever gunk that’s on my rooftop (which can be anything from dead leaves to monkey poop) is flushed down the gutter and into the water tank. This can be a major no-no for some of us.

 

A first flush diverter stops this from happening by diverting the first few litres (which will contain the gunk) of rainfall away. The diverter will then fill up and close itself via a floating rubber ball, which will then direct further incoming water (that is free from gunk) into the water tank.

 

This upgrade will be installed pretty soon, just as an extra hygiene measure (even though the water has been just fine thus far). 

 

 

2. Filter for Drinking Water

 

If you prefer to have drinkable water straight from the tap rather than having to go around boiling it, you can add additional filters to get the water to clean, drinkable levels. 

 

Right now, I only have one-step filtering system that takes care of dust and the like. To filter out the microscopic things floating in the water, I would have to install another two steps of filtering. Am currently happy to boil water when I need to, so this upgrade will be put on a back burner, at least until I either: a) get too lazy to boil water for consumption, or b) come down with water poisoning from the water in my tank (both of which have yet to happen). 

 

 

3. Additional Storage Tanks

 

The current tank is more than enough for now, but in the future, I do foresee a need to install more storage tanks in order to capture and retain more water, especially once I get the washing machine in and the gardens going. 

 

 

***

 

There you have it - a straightforward rainwater harvesting system, in a place with plenty of rainwater to harvest. 

 

You don’t need to build a house to be able to benefit from rainwater harvesting - as you can tell from the above, it’s a relatively simple system to setup, and at its most basic, requires only a barrel and a pipe.

 

Give some thought to how you can take advantage of the rainfall in your area - you don’t need to use it for human activities like I do; simply catching rainwater to water your garden and backyard or to wash your car is a good start!