Therefore, when building houses, rainwater is kept in the patio in the way of returning four waters to the hall. The bottom of the patio has a permeable pavement with a flexible basement (is paved with stone bricks placed in argil and sand), so it is permeable for rainwater and can store rainwater. However, there is a certain gap between the bricks, and the water will slowly infiltrate into the underground to supply the underground water. In addition to preventing excessive water storage caused by heavy summer rains, drains are also set up on the side of the patio to drain excess rainwater(Figure 6).