How does Chunjing in Donghai County forecast the weather?

In Jiazhuang Village, Liang Shi River Township, Donghai County, Jiangsu Province, villager Yang Mingji's family drilled a 6-meter-deep spring well at 1977. This well has been able to forecast rainfall accurately for many years.

The normal water level of this well is1.3 ~ l.5m, and the water is clear and sweet. In case of drought, the water level of the nearby well will drop, but the water volume of this spring well will not decrease. But whenever the weather turns cloudy and it is going to rain, the water level of this well will suddenly drop by about 40 cm, and the well water will become turbid, which indicates that it is going to rain. But this phenomenon is actually quite common.