This was accomplished by finding rainfall amounts for a five, fifty, and one hundred year flood cycle event. The rainfall amounts were then compared to the retention pond area to determine whether or not the ponds will be successful. Flood Cycle Events Determining a basic amount for a flood cycle event can be a tricky matter. The problem lies in the fact that there is no fixed amount that determines a specific rainfall event. Measurements of rainfall are related to frequency, intensity, and duration.
Floods can occur in a variety of ways and fall under different categories.
If you were to look at a graph, the categories would be represented by a curve. Here is an example. Precipitation was measured on three separate occasions. On one occasion, 5.54 inches fell in two hours. The next rainfall produced 4.53 inches within one hour.