August/September 2003
By Robert Foley
How a master plumber harvests rain for his drinking water.
RELATED CONTENT
Your woodstove can heat more than your home. This hot water heating system uses extra heat to produ...
There are several types of solar water heating systems. Learn more using solar energy to heat water...
Laid-up masonry basement walls on concrete footers are sturdy, economical, and comparatively simple...
On-demand water heaters provide an “endless supply” of hot water, but are they really “green”? Ther...
A guide to hiking and camping, including necessities, packing, clothing, navigation, cooking....
My subdivision's water originates from a typical Texas well, and it is hard with a capital "H" It also is expensive, and so heavily chlorinated that water from the kitchen faucet smells like that of a swimming pool. That's why I decided to build my own water system, trading in hard, chlorinated well water for soft, free rainwater. With our average annual rainfall of 31 inches, I knew I could collect 20,000 gallons a year from the rooftop of my small house.
I am a retired master plumber, so I had piping knowledge. I went to work to design a low-cost rainwater harvesting setup.
BUILDING THE SYSTEM
Rainwater harvesting begins with a simple idea: Rain gutters already are collecting the water that falls on your roof. To harvest that water, just set up the gutters so that instead of running onto the ground, the water flows into a storage tank, or cistern. It also is a good idea to put in a roof washer to divert the first few gallons of rain coming off the roof, along with any dust or bird droppings that water might be carrying. (For more about harvesting your rainwater, see Page 42.)
I was lucky enough to acquire some free storage tanks. A friend of mine is a water well contractor, and always has plenty of used pressure tanks. I was able to take eight of them off his hands for my project. Of course, they all had small holes in them, which meant they would no longer hold pressure, but for my use, that wasn't needed. All I did was patch the holes with a little metal epoxy so they would hold water.
Full tanks of water are very heavy, so I needed a good, solid foundation, or pad, to keep them stable. I used 8-foot landscape timbers to create a square form. and covered the area inside the square with plastic. I mixed one shovel of Portland cement to five shovels of sand, filled the whole area with this mix, tamped it, and then sprinkled it with water. It worked perfectly as a foundation for my tanks.
Each of my eight tanks holds 120 gallons. I hooked them together at the bottom with 1 1/4-inch PVC pipe, which allows water to flow back and forth just as though I had one big tank. Presto, I had 960 gallons of storage capacity. Later on, I added a commercially built poly tank. The cost of this tank was about $600, but I now have a total storage capacity of 2,510 gallons.
A simple 1/2-horsepower shallow-well jet pump and a 5-gallon pressure tank, set at 50 pounds per square inch, distribute my collected water. By priming the pump and plugging it in, I can use my supply of soft rainwater for many things. I can wash my truck (without water spots!), water the garden (I can make it "rain" anytime I want), and wash laundry and windows.