Extreme flow factors are generally used for computing peak discharges, and therefore are typically referred to as peaking factors or peaking equations. However, since they can also be used to compute minimum discharges, the term extreme flow factor is more accurate and will be used throughout the program and documentation.

Drainage and Utilities defines tabular and equation extreme flow factor methods in the editable Engineering Libraries, thus allowing you to edit predefined methods and insert new ones. The extreme flow factor can be user-defined with either of the following:

• Equation extreme flow factor method

• Table extreme flow factor method

In both cases, the extreme flow factor method can be a function of either of the following:

• Contributing population

• Base Load

Discharge based extreme flow methods can be used with any unit dry load. Population based extreme flow methods can be used only with population-based unit sanitary and non-population based unit sanitary loads that have population equivalents specified.