Simple System Basics
The storage tank, or cistern, can be made from almost any material—even a clean recycled metal drum. Gardening stores sell 55- to 75-gallon plastic rain barrels, complete with leaf screens and spouts, for $50 to $250. Wooden barrels have a nostalgic charm, but they're hard to come by and expensive. A wine or whiskey barrel made by a professional cooper will cost at least $250.
Larger storage tanks can be made of stone, cement, metal, wood, or fiberglass.
To prevent mosquitoes from breeding in tanks, make sure the tanks are covered or screened. Also, during winter months, barrels should be kept only three quarters full to allow freezing water to expand.
Gravity is the easiest (and cheapest) way to move rainwater out of the tank. Systems that work by gravity are good for watering landscapes; you only need to open a spigot or valve at the bottom of the tank. However, if you have to move water to a level higher than the tank, you'll need a pump.
A 1-horsepower electric jet pump mounted in a small shed near the tank costs about $400, and can provide about 8 gallons of water a minute up to 500 feet away from the water tank.