The DSS operates as a time series analysis.

So basically you start with an existing condition model run, or no action alternative if you will, which produces baseline output for each decision variable over the course of a given year and summarized for the period of record. Initially, it is against this that one will compare an alternative. That alternative is generated and the operational changes are reflected in a different flow regime overlaying the baseline conditions. So you can see exactly what the effects of that alternative were everything else being equal. I say “initially” because subsequent runs can of course compare one alternative against another. It is an iterative process and it is all based on the actual hydrologic conditions during the period of record.