LIGHTING A CANDLE INSTEAD OF CURSING THE DARKNESS
A simple rainwater catchment system
In fairness, until the recent drought problem we have not had any major interruptions to our water service since 2008 and early 2009 (plus the time the road construction broke our water line and left us dry for nine days (well, just me, really, because Brandy was away on a visit).
For the occasional glitches we have a reserve tank, pump and pressure tank. But we all want an ace in the hole. Ideally, that ace in the hole would be a nice, ever-flowing stream passing through or along the border of the property. But most of us don't have such a luxury.
So, reared in magnificent ugliness in back of our house is my particular version of an ace in the hole. It's a rainwater catchment system that can provide water for “might near” anything---mopping floors, watering plants, washing dishes, drinking (when run through our British Berkfeld filter), watering plants, etc.
If you're interested in having a similar system, it is not too difficult to build, and you can easily get the idea and design your own version after looking at a couple of photos of the system.
Here is an overview shot:
If you don't have a convenient platform for the barrels as I do with the propane gas storage cage, you may need to build a frame with cariolas or timbers.
The pipe on the upper right comes from a gutter. Water flows downward into the four-inch diameter pipe, carrying the first water off the roof along with dust, bugs, bird droppings or whatever. There is a little spot near the bottom of the pipe with a sort of orange stain below it. That is a bleed hole that allows water to run out, but only slowly. Consequently, when there is a large flow of water from the roof the hole can't let nearly all of the water out. So the big pipe fills with water (hopefully with all or most of the dirty stuff in it). Then it begins to overflow through the lateral pipe. The lateral pipe has a slight up-slope so that water will not flow through it until the big pipe is full.
As rain continues to come from the roof, most of it flows through the lateral pipe and into the right hand barrel, though a small amount continues to leak from the bleed hole.
Here is a picture of the barrel connections:
After the right hand barrel is full, water flows through the crossover pipe to the left hand barrel. Both ends of these connections into the barrels must be sealed at least moderately well. Water will flow across only when there is water still coming down from the roof and in the downflow pipe at a level higher than the crossover pipe..
When the left hand barrel is full, water then flows out of overflow pipe on the left and spills to the ground.
The faucets are mounted on the barrels a few inches above the bottoms so that any sediment that makes it into the barrels will not flow out of the faucets.
When the rain stops, water continues to flow from the bleed hole, draining the large pipe. There is a removable clean-out plug at the bottom of the large pipe. Periodically it is opened and the collected dirty stuff and a small amount of water allowed to come out.
The collected rain water is rather clean and very useful. Obviously, if you use it a lot during the dry season you may run out between rains, but it's a good back-up system that you may want to consider.
Bob Gregory (resident Rube Goldberg)
Replies
There was not a lot of location choice in our situation, but some folks may be able to rig a gutter at the edge of the roof on the shady side of a house.
Probably the best defenses are that the tanks are dark colored plastic that don't let light in and they're sealed pretty tight, which keeps the critters out (unless they ride in with the water). That's where the washdown trap comes in by accepting the first (dirty) run-off water so that it doesn't go into the barrels. Of course, nothing is perfect. We would not normally use the water for drinking or cooking without first filtering it in the British Berkfeld (Berkey) filter which provides 99.9% pure water.
We had one in Florida and it was wonderful to water the plants and to have "free" water if we needed it. Great idea.
We have four interconnected barrels that catch runoff from our gutters, which system we installed, with a pump, shortly after completion of our house in 2007 upon the recommendation of our landscape designer, Steve Walker. The system's primary purpose is to pump water to the back, upper part of a large garden in times when there is scant rainfall, but it also serves as a second backup system, as you describe. It's indispensable for its primary purpose, garden irrigation, and it's there for us when the primary source of water is out for long periods of time, exhausting our principal backup tank--fortunately, rare in our Palo Alto neighborhood.
This is an excent catchment system. The Boquete Rotary Club, in the rebuilding of El Banco School, also included a very inexpensive, simple and very effective water purification systems that would fit with your design very well and might not require the sophcistication you describe.
I invite you to check out "Waves For Water" at http://www.wavesforwater.org/. This group exists to make sure every person on earth has access to clean water. As a tired, broken-down sufer, I'm especially atuned to water problems. Rotary installed this system in about 5 minutes. Check out the specifications and cost of the system. It works!
Where did you get the barrels?
I bought one of the barrels at a company on the north side of the InterAmerican Highway a kilometer more or less east of Plaza Terronal. The other one was used to ship donated clothing. It had a square opening cut in the top. I made a cover of galvanized sheet metal (zinc liso), sealed it with silicone sealer and fastened it with self-drilling screws.
When possible, get barrels that have been used for foodstuff. The one I bought had been used for concentrated vinegar.