Last year I started to harvest rainwater from one side of my garage roof using discarded 55-gallon plastic drums. I used the water for my one tomato plant and various flowers around the house. It worked great and I never ran out of water, but even better, I never used domestic water from the house to water the plants. This year things changed, I planted a 200sf garden in the back yard and more decorative plants around the house, all these plants demanded more water, and even worse, the City’s water department raised their rates by 17% making domestic water too expensive to be used outside. Within a few weeks into Spring, I had ran out of the 150 gallons of stored water a number of times and realized I had to increase the capacity.
I determined I could double the storage capacity by adding 3 more barrels to the existing system and bring my potential capacity to 300 gallons. I bought 3 more barrels and altered them to work with the existing system. I stood back with pride admiring my handy work, and then I waited for the rains.
After a few days we had a heavy downpour that easily would have filled up all six barrels. The following morning I went outside to admire my ingenious design. I opened up the last barrel expecting to see it full of water, only there was none. So I moved to the second to last barrel, same outcome, bone dry. By now I knew something was wrong so I checked the first barrel, it was full. Okay, this was good, I had some water, but the second barrel was empty, this wasn’t good and the ground was flooded with standing water. I had a major problem and only one full barrel. I checked all the connections to make sure they were tight and not leaking, everything seemed okay. I was stumped. Then I took a step back and studied my design for what was wrong. Getting down to eye-level I noticed that the overflow from the first barrel to the second barrel was flowing uphill. You don’t need to be a hydro-engineer to know water doesn’t like to flow uphill.
After a few minor adjustments and some physical persuasion, I made sure the entire system was flowing downhill for proper drainage. After waiting almost 2 weeks, and being forced to use domestic water to irrigate my garden, we finally had a decent rainstorm. I ran outside the following morning and opened up the last barrel, it was almost full! The system worked and it was holding water.
Problems:
-I didn’t have enough room on the back of the garage for a 6th barrel. The system was altered to hold 250 gallons instead of 300gallons.
-Water doesn’t drain uphill.
Construction:
-To keep cost down, I eliminated shut-off valves at each barrel by attaching a 5’ long section of hose that terminates above the water line. To stop the flow of water all you need to do is raise the hose above the barrel.
-Sections of corrugated pipe were used between each barrel for overflow from one full barrel into the adjacent empty barrel. One barrel overflows into the next and so on down the line, simple and cheap.
-Each barrel has it’s own hose located at the base of the barrel and is secured at the top with a simple broom clamp.
Water calculations:
1 inch of rain on 1 SF of roof = .62 gallons. 1 inch on 160 SF should = almost 100 gallons. I’m only capturing rain from half of the garage, which is approx 120 SF of roof. I should be able to get almost 75 gallons out of an inch of rain! One heavy rainstorm in the spring should fill the system up overnight. Next year I think I might attach the other side of the garage into the system.
-Brian
Labels: Rain Barrels
