Properties of a flood simulation layer can be updated after a simulation is run.
Redefine the area of interest
The area of interest can be reshaped or moved after the simulation layer has been created. To do this, either click Modify 
in the Region group of the Simulation tab, or right-click Area of Interest in the Contents pane and click Modify . This will show a set of interactive handles to move, rotate, or scale the existing area of interest, as well as the simulation toolbar which provides tools to replace the area of interest with a newly defined one.
Note:
The extent of the area cannot exceed 14 kilometers in length. If you try to make it larger, a warning is encountered and the area is clipped to the maximum value.
Once you are done redefining the area, click Create Simulation in Area 
in the simulation toolbar to save the changes.
Update simulation parameters
To update the parameters of a simulation layer, right-click the layer in the Contents pane and click Configuration 
. Alternatively, click the launcher button 
in the Configuration group of the Simulation tab. The Configure Simulation pane opens loaded with the current parameters. Once you are finished updating the parameters, click Apply to save these changes.