A cistern is simply a collector of water.
Some people collect 'gray water' which is household water from showers, sinks, and washing machines. 'Gray water' can be collected and reused for irrigation and to refill toilet tanks.
After the gray water is flushed through a toilet it becomes 'black water'. In this system, our cistern collects rain water from our gutters and roof.
The tank is a 1600 gallon tank and seems to be able to fill completely with about 1/2 inch of rain. We then use this water in a drip irrigation system for our plantings of fruit trees and bushes.
