There will be times when it is convenient to confine statistical analysis and cumulative frequency curves to a particular range of flows. It may be necessary to exclude periods of zero flow when assessing compliance with guidelines, or periods of baseflow and stormflow may need to be addressed separately. This can be done by specifying a Flow Threshold at any point.
You can select upper and lower flow thresholds as shown in the Figure below and Apply Filter. The thresholds modify the analysis at that point, but not the underlying simulation.