300 Gallons of Rain Water Storage
Part 1 of Building a Six-barrel Rainwater Collection System
Rain barrels are a fantastic idea. Not only will they save you money, most houseplants would love to have rain water (especially spider plants, it will keep them from getting those brown tips). You can also use that soft water for young seedlings or anywhere else in the garden. But we have a fairly extensive garden with lots of fruit plants and a small orchard, and 50 gallons of stored rain water doesn't stretch very far. We're going to need a bigger barrel. Or two, or four, or even six!
How We Will Build It
There is a shed in one corner of the yard with a narrow space between it and the fence. This space is useful for storing lumber but inconvenient to access, so we're going to place six plastic barrels there instead, and they will store three hundred gallons of rain water.
One side of the shed roof will collect the rainwater. We would prefer the system to manage itself, so we will also incorporate an automatic overflow to dispose of the excess water when the barrels are full. But we will also want to keep this low tech, which means no moving parts except for the faucet.
How much rain will we need to fill the multiple barrels? An inch of rain on one square foot of collection area will produce 0.63 gallons of water. This side of the roof has a collection area of 80 square feet. That means an inch of rain on this roof would provide 50 gallons of water (80 X 0.63), and six inches of rain would fill all six barrels (80 X 0.63 X 6).
Update 4/10/10: Since we completed this project we have received around five inches of rain. The barrels are about three-quarters filled.
Roughly a four foot by fifteen foot space. There is a french drain underneath that gravel.
Test fit, looks like plenty of room, full speed ahead! Let's work on the barrels. Lots of pictures!
Page 1: Introduction (this page)
Page 2: Putting together the rain barrels
(lots of pictures!)
Page 3: Finishing up with the rainwater
collection system