Rainwater Harvesting

Rainwater harvesting

Why we should collect this natural resource

Did you know that only 3% of the water supply on earth is freshwater? Of that 3%, only 0.03% is actually available to us. The rest is captured in glaciers, ice sheets, aquifers, groundwater or rivers & streams. So how we use this small amount of freshwater is critical. It’s important to be water-conscious and collect, reuse & recycle water as much as possible. 

We just made it through almost two weeks of relentless rain, and at the end of it, our two rainwater tanks plus the overflow barrel, which can hold 200L, were full. That’s 15,200L of rainwater in total! 

We consider ourselves lucky to be able to collect that much rainwater. After all, water is life and the most precious resource we have on earth. Furthermore, rainwater is a free resource delivered right to our doorstep. All we have to do is build the facilities to harvest, store and use it. So I encourage you to harvest rainwater if you are in a position to do so. 

Our rainwater harvesting system

Rainwater harvesting doesn’t have to be complicated. It can be as simple as putting a bucket out in the rain. This water could then be used for indoor plants, for example. But, of course, there are more efficient methods of harvesting rainwater and different ways to suit all kinds of setups, from a small balcony to a full-on farm. 

Our rainwater harvesting system is simple and works as follows:

Almost four years ago, we started with a 10,000L tank to collect the water from our roof. Since we live in a tiny house on wheels, our roof catchment is considerably smaller than an average-size house. Nevertheless, we do not have any issues filling the tank. Our records show that between February 2020 – June 2021, the lowest tank level was 70%. For the majority of this period, the water level was between 100% – 80%. It is a great result considering our small catchment area! Furthermore, we capture the overflowing water in a 200L barrel. I usually use this water for the chickens and to water my indoor plants.  

About three months ago, we built a carport and added a second rainwater tank to collect the rainwater from its roof. This rainwater tank is 5000L in size and dedicated to the garden. As my garden grows, so does the need for watering it, especially during our hot summers, and the filtered greywater alone is not enough anymore. 

Our greywater system

Because water is so precious, we want to make sure that we use it a couple of times before it goes back into the ground. Therefore, once we have used the rainwater in our house for chores like dishes, cleaning, laundry or simply for showering and washing, it runs through a natural reed bed filter. After the water has been filtered, it flows into a bathtub where it gets stored and then I use it for the pot plants in the garden. To learn more about our natural greywater system click here.

Benefits of rainwater harvesting 

There are many reasons for rainwater harvesting as it is beneficial for us on an individual and urban level but also benefits the natural waterways. 

As I mentioned before, if you live in an area where it rains, this rain is a free resource just waiting to be collected. Using rainwater for some of your water requirements reduces the dependence on mains water, builds water resilience, especially in times of drought & water restrictions and reduces your water bills. 

In urban areas & communities, rainwater harvesting reduces the amount of stormwater runoff & flooding which has substantial benefits on the sewer system and natural waterways like rivers & streams. Reducing the impact runoff has on the sewer system, has economic benefits because it reduces the amount of water councils have to treat & pump back into the system.

Furthermore, rainwater can be used as water for 

  • Laundry and toilet
  • Showers, dishes & other household uses
  • Irrigation in the garden & indoor plants since it’s free of chemicals
  • Livestock
  • Replenish groundwater


As I am diving deeper into my permaculture studies, I make sure that we live within our water budget and reuse & recycle water to the best of our abilities. In our case, our water budget is the rainwater we collect, which is 15,200L. Of course, not everyone can or wants to live off 100% rainwater, but we can all do our best to watch our water use and make an effort to save water. 

If you want to learn more about this topic, Kirsten and Nick from Milkwood Permaculture just published an informative online workshop about Rainwater Harvesting for Beginners. I highly recommend watching the video. It’s only 30 minutes long and provides useful tips & tricks for everyone who wants to start collecting rainwater.

  • Earth User’s Guide to Permaculture, Rosemary Morrow
  • Introduction to Water, Permaculture Education Institute, Morag Gamble
  • Rainwater Harvesting at Home for Beginners (video), Milkwood Permaculture

Posts created 58

3 thoughts on “Rainwater harvesting

  1. You mention chickens in your post. I would enjoy reading an article about your experiences with raising them. Do you raise any other livestock?

    1. Hi,
      Thanks for your comment and for enquiring about our chickens. We got them from a local chicken rescue organisation that rescues chickens once they’re no longer deemed productive. Therefore, we got them as adults when they were about 18 months old. So technically we don’t raise chickens. They still lay eggs but that’s not why we got them. We simply wanted to provide them with a good home. We don’t have any other livestock. I might write an article about our rescue chickens, thanks for the suggestion.

  2. Since your water tank is large & your water usage is fairly low does the water tank ever get dirty or grow any algae if it sits for a while? What filtration system do you use & how often to you have to replace any filters? Also do you use a pressure tank along with your water pump?

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