I was going to start this post by saying how much I hate it when I come up with a great idea only to find out that someone else has already beat me to it. But in reality, I don't care that much. It makes be feel good that I had an idea that works!
My idea was to have a large circular sail that could open up flat (horizontal) when it rained. It would have a very large surface area of at least 1,000 square feet (300 square meters). This would be used for rain water collection, mainly for livestock tank filling, but also for human consumption as well.
The simple, yet elegant, RainSaucer.
Then, just a few days ago, I heard an interview with Tom Spargo on The Survival Podcast. This gentleman created a scaled down version of my idea... okay, so it was his idea! :)
The RainSaucer can easily be connected to many different systems.
The RainSaucer is a rain harvesting tool. It is portable. It is durable. It can be connected to many different collection systems (buckets, barrels, troughs, etc.) It is also not that expensive at only $55. He has completed many field trials in Guatemala providing locals with inexpensive ways to obtain clean drinking water.
RainSaucers incorporated into a trellis on a sustainable garden. Love it!
No, I don't own stock in this company (I doubt they actually have stock), but I see a great product here. This is one that will be incorporated into my Permaculture System in the future. Here is a link to the only place the currently sells the RainSaucer online, but I think that will change quickly as this company continues to grow. And here is a video on installing the RainSaucer. It shows how simple this system is, and typically all great ideas are simple but brilliant.
Permaculture Swales
In Permaculture, a swale is a method used to harvest rain water. They are long shallow trenches that run along the contour of the land. This means that swales are perfectly level. Swales do not direct water flow, but they collect water. The soil removed from the swale is piled on the downhill side to make a slightly raised bank or berm. When rain falls, the water runs along the surface of the topsoil, and it will collect in the depression of a swale. The water will slowly seep into the soil and collect in underground pockets that will supply the roots of plants through weeks and even months without rain.
Illustration showing the water storage of a swale - from Gaia's Garden
If rainfall is heavy or fast enough, the water will also slowly seep into, through, and maybe overflow the berm. Since the swale and berm are level, the water gently slips over the edge, and no erosion takes place. The water then travels downhill to the next swale.
Plants are planted in the downhill berm. The roots keep the berm in place, and the water provides moisture to the plants. Water loving plants can be placed further into the depression of the swale, and plants that require less water can be placed further downhill of the berm.
As time goes on, rain and wind will continue to push and carry silt and other debris into the swale which will slowly build up a compost-like rich soil. This will only continue to benefit the plants near the swale.
Swales can be very large or very small. They can cover large fields or small yards. The key to making swales is keeping the swale level. There are many techniques for doing this. Two handmade leveling devices are an A-frame Level and a Bunyip (water level) which were both used by the Egyptians. If you have the ability, you can also use a laser level or other surveyor's tools.
When the reading is the same on both sides, then the base of one stick is on contour (is level to) the other stick. Mark a line with chalk or paint or string from one stick to the other, and you have marked the contour of the land.
The distance between swales is really determined by rainfall. Swales should be closer together in areas with high rainfall. According to Toby Hemenway, author of Gaia's Garden, they should be spaced 18 feet in areas with 40-50 inches of rain, and 50 feet in areas with 15 inches of rain.
The following images are of a larger swale system being built. As you can see, the contour of the land typically creates a curved pattern across the land, NOT straight lines. Rarely are there any straight lines in nature.
Note that the depression of the swale in this photo has been packed with straw. This allows a more formal appearance to a yard (instead of standing water) while still retaining the water harvesting and storage capabilities.
In even smaller settings, you can create a Fish-Scale Swale.
Note that this swale will be filled with straw mulch and then covered with a thin layer of topsoil. No one but the designer and the plant know the swale is there. Perfect for those who don't want a yard with "ripples" yet still want the benefit of the swale systems.
If you live in any area that does not receive regular rainfall and has weeks to months where no rain waters your plants, then I strongly suggest looking into Permaculture Swales.
This is is just going to be a quick post to reference the formula for calculating how much water can be obtained from a roof (it is A LOT, by the way).
Formula for calculating rain collection - fromGaia's Garden.
For those who don't like to do a lot of math, here is a quick reference for rain water collection.
The basics of rain harvesting from your roof is quite simple. First you need gutters. Then you need somewhere to store the water. That is it. To make things more efficient, your storage tank is situated above (higher) than the location you need it, so gravity will take it to where you need it.
Traditional style of rain barrel.. what most people think of.
Here is a more detailed diagram of a rain water collection system. If you are going to reuse the water in your own home, there are a few additional components to think about. First is a pump. If you are fighting against gravity, this is obviously needed. Second, a filtration system is needed if you will be drinking the water. Third (or maybe considered part of the filtration system) is a way to separate the first water off the roof which carries roof dust, bird droppings, and other particles that you don't want in your water storage tanks. These contraptions go by various names such as "roof washer", "flush diverter", or "first flush diverter".
Note the ball that floats as the first roof water flows past.
As the water rises (and becomes more and more clean) the ball will eventually form a seal, and the clean rain water will be diverted to the storage tank.
