Rainwater harvesting is a simple, ancient technique of capturing water from the roof of your home, garage, barn, or any structure that is displacing water and storing it for later use in a storage vessel (also known as a cistern).  This water can then be used for various non-potable uses such as landscape irrigation, car washing, toilet flushing and fire protection as well as supplementing both private and municipal water sources.  With proper filtration and disinfection, the water may be used for potable applications as well.

Systems may range from a simple rainbarrel used as a gravity-feed water system for landscape irrigation to large applications such as schools or plants, where the water has several uses and the system acts to aid fresh water conservation and stormwater management.

In many areas, rainwater harvesting is a necessity, not a luxury.  Most volcanic islands have little to no fresh water resources.  As a result, they must depend on rainwater for most of their water needs.  Hawaii, Bermuda and St. Croix are all examples.  Rainwater harvesting is also required in many arid Southwestern states on all new construction to aid water conservation.

Buildings can capture 600 gallons of water for each 1000 square feet of roof area during a 1 inch rain event.  Many states and municipalities are encouraging or requiring rainwater management and even subsidizing installation of these systems to help fresh water conservation and stormwater management.  Fresh water is a finite resource that must be protected!