How to Create a new HEC-FIA FDR Study from Scratch

This tutorial creates a new HEC-FIA study from scratch, and builds from the steps outlined:

HEC-FIA Flood Damages Reduced Geospatial Data Collection

GIS Processing for HEC-FIA Flood Damages Reduced Simulation

Create a New FIA Study

1. Launch HEC-FIA and go to File - New Study
2. Enter a Study Name, Description (optional) and navigate to your Directory. Unit System defaults to English. Once information has been entered, select OK.

Import Map Layers:

1. Right-click on Map Layers and select Add Map Layers
2. You will want to add the following Map Layers. You do not need to add your 2D Areas. These Map Layers were developed in the above tutorials.
   1. Computation Points (ResSim export that has been edited down)
   2. Geometry Region (RAS export)
   3. Reservoir Pools (ResSim export)
   4. Rivers (RAS export)
   5. Storage Areas, if applicable (RAS export)
   6. Cross sections, if applicable (RAS export)
   7. Structure Inventory (processed in ArcGIS Pro)
   8. County Boundaries (processed in ArcGIS Pro)
   9. Storage Areas with the River Names, if applicable (processed in ArcGIS Pro)
   10. Holdout Areas (processed in ArcGIS Pro)

Import Terrain Grids:

1. Right-click Terrain Grids and select Add Terrain Model.
   
   
   
2. Navigate to your RAS terrain and open. The terrain must be a *.tif or *.vrt. This will create a reference to the terrain in the HEC-RAS folder. It will not copy the full terrain. 

Import Reservoirs:

1. Right-click on Reservoirs and select Import
   
   
   
2. Select your reservoirs shapefile
   
   

   Make sure that your Reservoir Name matches the reservoir Holdout name. This should have been done when going through the steps on the GIS Processing page but if it was not, do so now.

3. Enter a name, Reservoirs
4. Under unique name, select ID_NAME
5. Check the reservoirs if they are Corps Projects
6. Select OK.

Import Rivers:

1. Right-click on Rivers and select Import
   
   
   
2. Select your Rivers shapefile that was exported from HEC-RAS. If your HEC-RAS model has 2D grid areas that break up your river centerlines, HEC-FIA may not allow you to import them outright. You may need to process them in ArcGIS Pro. Another option would be to export your stream alignments from HEC-ResSim but you would also want to process these further in ArcGIS Pro by deleting streams and/or stream portions that are not within the study area. See GIS Processing for more information.
3. Enter a name, Rivers
4. Change the Unique Name to River and then select Import for the Rivers you would like to import.
5. Select OK.

Import Cross Sections. If you are using gridded output, this is not applicable:

1. Right-click on Cross Sections and select Import
   
   
   
2. Select your shapefile and then select the appropriate fields. Part B will also be River Stat (same as Station). Once done, select OK.

Import Storage Areas, if applicable:

1. Right-click on Storage Areas and select Import
   
   
   
2. For the file, you will want to select the Storage area that has the River names attached (processed in ArcGIS Pro)

Import Computation Points:

1. Right-click on Computation Points then select Import - CCPs with Holdout Distribution Areas
   
2. Enter a Point Set Name
3. For the CCP Shapefile, select the Computation Points shapefile. You will want to select the edited CCP shapefile where there is one CCP per Holdout area.
4. CCP Name, select ID_NAME
5. CCP A Part, leave it blank
6. CCP B Part, select ID_NAME
7. Holdout Distribution Area Shapefile, select the HoldoutAreas shapefile that has the names associated with it.
8. Holdout Distribution Area Name, select ID_Name. Once this is done, the table will populate with CCP names on the left, and holdout area names on the right. If the names are the same, they will match automatically. Can check and adjust as needed.
   
   
   
9. Stream Alignment, select Rivers
10. Reservoir Set, select Reservoirs

Create a Watershed Configuration

1. Right-click on Watershed Configuration and select New
2. Enter a Name: provide it a name consistent with your watersheds naming convention.
3. Select the Terrain, Reservoirs, Rivers, Cross Sections, Storage Areas, and Computation Points layers previously set up. Then select OK
   

Import Geographic Data

1. Emergency Planning Zone is required
   1. Right-click on Emergency Planning Zone and select Import.
   2. For the Shapefile, either use holdouts or geometry region. For this model, the StudyArea shapefile was selected to keep it simple and as it is one polygon and it will encompass all the structures.
      
      
      
2. Boundaries are optional but can be state, county or watershed. For this study, import counties so we can view results by county.
   1. Right-click Boundaries, select Import.
   2. Select counties shapefile
   3. Name the file Counties
   4. Change the unique name to County Name.
   5. Check the Counties you would like to Import and then select OK.
      

Set up Inundation Data

There are multiple Inundation Configurations available to compute Flood Damages Reduced Simulations in HEC-FIA

For more information, review:

Dams and Levees - How to Create RAS Holdout HDF - Flood Damages Reduced Computation in HEC-FIA and CWMS

Dams Only - How to Create RAS Holdout HDF - Flood Damages Reduced Computation in HEC-FIA and CWMS

Dams Only - Flood Damages Reduced Computation with Grids in HEC-FIA and CWMS

The below example highlights how to setup the Inundation Configuration for a Dams Only with Grids Simulation. More information can be found in the above tutorial. 

1. Right-click Inundation Data and select New
2. For the name, enter a name that is descriptive. For this, we are going to name it Holdout-Grids1
3. For Hydraulic Data Type, select Holdout Grids
   
   
   
4. Select Next
5. Select your Watershed Configuration
   
   
   
6. Right click on newly created Inundation Holdout-Grids1 and select Define Event
   
   
   
7. Fill out the Holdout Grids Event window
   
   
   
   1. For this tutorial, we have a September 2025 event so will name it Sep2025
   2. Select your HEC-RAS regulated grid output - you will want the Depth (max) in vrt format.
   3. Select your HEC-RAS unregulated grid output - you will want the Depth (max) in vrt format.
   4. Check the box that you want to use the HEC-ResSim holdout time series.
   5. Navigate to the forecast.dss
      1. For the E part, select your time step. It will be buried within the date/times. 
         
         
         
      2. For the F part, select the HEC-ResSim F-part as it appears in CWMS 
   6. Select OK

Import Structure Inventories

Before you import structure inventories, you will want to make sure that you have Occupancy Types Set

1. Right Click on Structure Occ. Types and select Import from Defaults
   
   
   You can check the import by right clicking again on Structure Occ. Types - Edit - Table Editor
   
   
   
2. If not already completed, you will want to import your structure inventory. Right click on Structure Inventories folder - Generate From - Point Shapefiles
   
   
   
3. From the shapefile dropdown, select your NSI shapefile and enter a name
   1. For the Data Assignments, select the appropriate items from the dropdowns
   2. For the Optional Data, this table will initially be blank. Will need to select the Inventory Field and Shapefile Fields from the dropdowns.
      
      
      
   3. Select OK

Setup Alternatives, Time Window and Simulation

Create a new Alternative

1. Right-click on Alternatives and select New
   1. Enter a name (FDR)
   2. Select the EPZ, Inundation Configuration and Structure Inventory as shown.
   3. This is all you need so once done, select OK.
      

Set a Time Window

1. Right-click on Time Window and Select New
2. Enter a name
3. Enter simulation date and times. The Simulation Times should match the RAS output window.
   
   
   
4. Select OK

Create a Simulation

1. Right-click on Simulation and select New Simulation
2. Enter a name, for this example Sim1
3. Then Select Add to link everything - select your Alternative, Event and Time Window
   
   
   
4. Select OK.

Run the Simulation

1. Scroll down to your Simulation (Sim1) and select it. Then right-click and hit compute. (You can also click on the running man just below)
   

View Results

To view results, select the Simulation in the lower left corner, right-click and select Flood Damage Reduction Aggregated Report.