Catching the natural rainfall to store for later use helps conserve water and energy. A water catchment system can be adequate enough to provide most of the water needs for a water-conserving household, outdoors as well as indoors, by simply catching what falls on the roof.
Catching Rain is not only for use in your garden and yards but can cut down on the need to rely on city and county water, reduce energy consumption as well as greatly reduce water bills. Rain barrels can easily be sized for the amount of use, beyond using them in a garden, and remain relatively easy for an owner/builder to install for household use.
Here is a video from HGTV- How to Build a Rain Barrel.
Below are some helpful websites to get you on your way to conserving water.