Collecting rainwater is a very dear subject to myself, and Bill Mollison illustrated this very eloquently: “If you only do one thing… collect rainwater”.
What he probably meant by this is that collecting rainwater is a simple yet impactful action that enables anyone to do many things that are within reach (such as growing food and creating soil) to contribute to this common endeavour: restoring our natural ecosystems to what they need to be in order to support our existence.
Before diving into this subject, I’d like to give credit to Brad Lancaster, a Permaculture Designer, author and social activist from Tucson, Arizona, who has been a very influential figure in my life.
The story below by Kirsten Dirksen, an independent ethical journalist which you can find at https://faircompanies.com/, literally gave me the impulse to become a Designer myself; after seeing the many water harvesting techniques that are possible in any given context, and what their potential for change and social empowerment, I embarked on my own personal Permaculture journey.
Observation
Becoming aware of the water flow during rain events is the inception point for everything that is done. To collect rainwater is first to realise where the potential is, either in relation to buildings or the larger landscape.
Where water pools also informs you about topography and soil quality and type. Where this happens, there is opportunity for either a very productive space, or for creating surface storage. If this is in a position higher than your garden project, then it’s worth going to every possible length to capture water and store it there for productive use.
If the pooling takes place at an altitude below your project, it is still worth storing. Many creative uses can turn this resource into much more (habitat for wildlife, mulch producing, raising waterfowl, even aquaculture).
Effective decisions can range from simple to complex, but they all need to stem from observation.
Where to Start ?
Start at the highest point. That is easy enough to decide, but in urban spaces it might prove to be quite a technical project.
While it might not be applicable to all situation, depending on precipitation levels and frequency relative to climate, but the research being done at the Permaculture Greening the Desert site in Jordan is very inspiring and informative:
While wicking beds placed on the roofs of buildings is not possible, or imperative, in many situations, the technique can inform you of the potential of low tech solutions. Depending on needs and resources, simpler techniques can be employed.
However, the principle remains the same: the higher up you are able to creatively and effectively use water, the more potential your projects have. More traditional solutions for urban spaces include water tanks aligned with the downspouts of rain gutter; beyond this point, the directives are:
- Prioritise infiltration into the soil
- Adopt multiples solutions
- Use gravity flow
What to do ?
Getting our hands dirty is imperative. But it doesn’t have to be complicated. The materials required for the techniques are mostly available and easy to implement, at a human pace.
Written works such as Harvesting Rainwater https://www.harvestingrainwater.com/, written by Brad Lancaster, can provide you with a lot of inspiration; don’t be fooled by the fact that the author is based in a dryland climate. In practical terms, it means that the empirical case studies he puts forth are relative to the most extreme events possible for urban spaces (drought and flood).
In terms of feasibility, almost everything he presents is applicable and recommendable in other climates, in and around cities and towns. As hard surfaces (roads, buildings etc.) are a constant of our contemporary life, the essential question circles around how to create a buffer zone that puts that water to good use.
As far as directives go, the core information can be concentrated in these four ideas:
- Intercept
- Slow
- Spread
- Sink
For getting a sense of how to make it work for your situations, then you can delve into Brad’s life work. His book is rich not only with techniques, but also with the diverse situations to which they were applied. Work on the ground had to be supported by work in the community, and he is a pioneer in that field as well. He has coined terms such as “pre-legal” to describe the process of empowering communities to act on their own behalf.
Techniques for Gardens
Writing about techniques that tend to rainwater collection in the garden itself, I’m assuming that by this point there is at least a basic degree of control over the flow of water in the other parts of the property.
The core debate I’d like to focus on is whether Raised beds or Sunken beds are appropriate to your climate and project. There are great points brought forth in this video from the Greening the Desert site in Jordan:
In practical terms, I have used both techniques, to create an advantage, or a niche, for a specific crop; in one case, I wanted the rainwater to be collected in a particular space, and be used by the plants for growth, and in the other I wanted the opposite.
Drainage was more important than retention. In imagining how the combination could work to my advantage, I based my decisions on observation.
However, in permaculture, we work with the smallest possible unit for design, which is the micro-climate. When considering what is appropriate to your project, this is the scale at which you can apply it.
I will close this article on this note: design is a feedback cycle to use to your advantage, for a practical result.
It might happen that the desired outcome is not what happens in reality; relying on the system to provide viable answers, instead of “fixed” knowledge, informs you of the appropriate decisions and techniques to use. The topic of rainwater collection is a long tale of options and decisions. Once it reaches its full potential, the natural succession becomes more and more visible in the form of growth and yield.
