Proper setup of the HEC-FIA model is a critical step in the process, as it computes economic losses from the input inundation data. HEC-FIA models for watersheds developed during initial CWMS implementations often do not receive much care following initial development. That said, in addition to modifying the existing model to perform FDR computes, you should update the model to include the best structure inventory data available. This section covers updating the HEC-FIA structure inventory, adding shapefile boundaries for aggregating results, and setting up new alternatives for the two approaches for computing FDR.