The pictorial diagram illustrates how stormwater is processed in an Australian city.
Overall, this system has five stages, starting with the collection of rainwater and ending with the distribution of treated water back to households. This process relies entirely on artificial purification methods.
First of all, rainwater is collected from rooftops through a series of drains. After that, it is transferred to a recycling plant. At this stage, plastic, rubbish, small particles, bacteria, viruses, molecules, and salts are removed from the rainwater. This improves the water quality, but it is still not completely safe to use.
In the next stage, chlorine (4 mg/L) is added to kill the remaining bacteria and improve water quality. Then, the filtered water is transported by pipes to a second storage tank to be kept for future use.
In the final stage, the purified water is piped back to houses and is used during dry periods.