For each of the scenario, create runs on the Batch Run window as below and then click Run button to finish the runs.

Scenario Name Design Storm Used for Runs
Existing 20mm, 25mm, 30mm
Post 20mm, 25mm, 30mm
Post-20mm-detention 20mm
Post-20mm-detention-10mm-IA 20mm
Post-25mm-detention 25mm
Post-25mm-detention-10mm-IA 25mm
Post-30mm-detention 30mm
Post-30mm-detention-10mm-IA 30mm

Before going to the next step of sizing ponds, we can quickly take a look at the results by using Scenario Comparison in the Simulation toolbar. Click the Scenario Comparison button to open the comparison window. For example, the figure below the comparison of flow under 20mm design storm. The flow in post-development is much higher than the existing conditions, and the same for the two scenarios with pond added, which means the pond must be re-sized to meet the mitigate the impact of post-development. Select from the drop-down list Design Storm to view the comparison results under 25mm and 30mm design storms.