The pictorial diagram illustrates how storm water is processed and reused in an Australian city.
Overall, the system has five main stages, starting with collecting rainwater and ending with supplying clean water back to houses. It is a fully artificial process with filtration and chemical treatment.
First of all, rainwater is collected from rooftops and goes through a series of drains. After that, it is transferred to a recycling plant. At this stage, different types of waste such as plastic, rubbish, small particles, bacteria and viruses are removed from the water. This makes the water cleaner but still not completely safe to use.
In the next stage, chlorine is added to the water in order to kill remaining bacteria and improve its quality. Then, the treated water is moved through pipes to a storage tank where it is kept for future use.Finally, the purified water is distributed back to houses and can be used especially during dry periods when there is no rain.