This is our rainwater harvesting system. It’s instrumental in keeping our garden irrigated.
We obtained two food-grade olive barrels (free!). I drilled a 1″ hole toward the bottom of the vertical side of the one on thre deck and another 1″ hole toward the top of the vertical wall. I installed a brass spigot in the bottom hole and a fitting with a 1″ I.D. tubing in the top hole.
Then I drilled two holes in opposite sides of the upper portion of the bottom barrel. The other end of the tubing with a fitting on that end plugged into one hole and serves as an automatic overflow from the upper barrel into the lower barrel. An inexpensive plastic spigot fitted into the other hole and serves as an overflow valve for the lower barrel.
Faye stapled window screen to the inside of the screw-on rings to serve as mosquito barriers. I had to do a little cutting on the downspout so the upper barrel would fit underneath. Then we put them in place.
Betweeen the two barrels we can store about 100 gallons (375 liters) of rainwater. Our various water jugs – repurposed laundry detergent, water, and vinegar jugs – add another 8 gallons’ capacity. For the past three years this has been more than enough to keep our garden, potted houseplants, and some specimen plants irrigated, and we have never run out of water. Our financial layout for the whole setup has been around $40.
We do not irrigate our lawn, either with harvested water or city water. While we like the look and feel of turfgrass we are gradually decreasing the amount of lawn. We are a little different from many people in that we do not see the point in watering and fertilizing something that you then mow, that you water and mow, that you water and mow, that you fertilize and water and mow . . .
We expanded the garden this year and this may test our water storage capacity. Only 13mm of rain has fallen since May 16. After the (probably overly) prodigious watering I did while Faye worked we have around 50 gallons between the two barrels.
It’s a bit of a fiddle to carry water to the garden. We are looking at adding eavestroughs to the shed which would empty into one or two barrels inside the garden area, shortening the carry.