According to the different rainwater sources, the rainwater collection system can be roughly divided into two categories:

1.Roof rainwater, the roof rainwater is relatively clean and with less foreign matters, mud and other pollutants, it can be drained directly into water storage system through split-flow and simple filtration for the utilization after processing.

2.Ground rain water, there are many foreign matters in the ground rainwater with complex pollutant source, after the split-flow and rough filtration, it must be treated through sediment then to be drained into the water storage system.