How To Collect Rainwater The image below shows the simple process of rainwater collection and the rainwater harvesting system as a whole. Rain is collected from your roof & filtered by fine mesh gutter screens prior to entering pipe conveyance.Collected rainwater flows to to your rainwater storage tank through “in-ground pipe conveyance.Rainwater enters your metal water storage tank and filters through a “leaf-basket” (not indicated below inlet).Stored water in your Aqualine Storage Tank is then pumped to your water filtration equipment using a submersible pump Non-potable rainwater is pumped to the water system equipment: carbon filter, sediment filter & UV purification.Treated water is then considered potable for household use. Rainwater Harvesting System Installation Timeline The image below depicts the timeline of a Turn-Key rainwater harvesting is installed by RainSaver Harvesting.