In Chinese folklore, there is a saying "Eight dragons control water" that has puzzled many. In ancient times, dragons were revered as rain gods. 

Excessive rainfall would inevitably lead to flooding, hence the concept of "water control." The phrase "Eight dragons control water, five oxen plow the fields, four people share the harvest" illustrates the importance of managing water resources for successful agriculture.

The importance of rain for crops is self-evident; it is crucial for a good harvest. Only with favorable weather conditions can there be a bountiful harvest. 
Ancient Chinese people used the first Dragon day of the New Year to predict the amount of rainfall for the year. 
The number of dragons on the first Dragon day of the New Year corresponds to the date, indicating the potential for water management.