Catchment: roof surface to collect the rain

Conveyance: channels or pipes from roof or catchment area to storage

Roof washing: "first flush" diverter system to filter and remove contaminants

Storage: Tanks where collected rainwater is securely stored – i.e. insect proof

Purification: includes filtration, ozone or UV light to purify the collected rainwater for potable use

Distribution: System that delivers the rainwater, usually including a small pump and pressure tank