Originally Posted by SunriseGardens
Irrigation to be for vegetable garden, trees, planting beds, no lawn maybe 1000 square feet total
31 inches per year
600 square feet of roof area, this calculated at 7400 gals per year
medium sized pond 2000 gallons or so
I was thinking around 1000 to 2000 gallons for the cistern
I would go with the 2000 gallon cistern (the more you can store, the less you have to buy).
Look into what Atlantic or EasyPro has to offer. I know that they both have Rain Harvesting Kits available. Saves having to buy material piecemeal.
How did you arrive at 7400 gallons per year. I came up with 11,500 gallons per year. 31" = 2.58' x 600' = 1548 cu/ft x 7.48 gallons = 11,579 gallons.