Flooding is a natural phenomenon occurred. Since in the past to the present. The most common from of rain fell heavily. And the current flood caused by many factors, but there are important factors 2 reasons. In the first place.Secondly, the second is the invasion area to residential and office building natural farmer culture. Especially water river and the area near the river. Due to lack of knowledge and personal interests.2 way. In the first method is an analytical relationship between the amount of annual maximum flood and the average rainfall in each station in the catchment basin with regression analysis method the relationship. (Regression Analysis).(Frequency Analysis).