Process

From cloud to tap in seven stages

Scroll through how a rooftop system captures, cleans and stores rainwater.

  1. 01

    Rainfall

    Rain falls on the building and its surroundings.

  2. 02

    Rooftop Catchment

    The roof surface collects rainwater; material decides the runoff coefficient.

  3. 03

    Gutter & Downpipe

    Gutters along the roof edge channel water into downpipes.

  4. 04

    First Flush

    The first, dirtiest runoff carrying dust and debris is diverted away.

  5. 05

    Filtration

    Sand, gravel, mesh or cartridge filters remove suspended particles.

  6. 06

    Storage / Recharge

    Water goes to a tank for use, or to a recharge structure underground.

  7. 07

    Reuse

    Stored water supports gardening, flushing, washing and more.

Diagram of a full rooftop rainwater harvesting system

Complete system: roof → gutter → filter → tank → recharge pit