Best Practices

  1. HEC-FIA 3.3 will not allow HEC-FIA 3.0 or older projects to be opened in FIA 3.3. To update a 3.0 project, first open the FIA project in HEC-FIA 3.2.1 or older and save the project. Then open the project in HEC-FIA 3.3 to complete the update.
  2. Upon upgrading to CWMS 3.3.1 and FIA 3.3, it is good practice to ensure the model linking for FIA is set in base before creating new forecasts. Additional instructions for setting up model linking for a Flood Damages Reduced Compute using the Holdout - RAS HDF inundation configuration can be found below.
  3. When a new forecast run is developed (for example a Flood Damages Reduced forecast run) it is recommended to compute a test event for the HEC-RAS and HEC-FIA alternatives in the base watershed. These computes can be completed by copying an existing forecast.dss file from a previous forecast had run through HEC-ResSim for the watershed, and then adjusting the HEC-RAS time window as well as the flow pathnames in the Unsteady Flow Data Editor. By ensuring the HEC-RAS output is created in the base watershed (including stored depth maps), model linking can then be completed for the HEC-FIA alternative.

Known Issues

  1. Viewing Results - In CWMS 3.2.3 and CWMS 3.3.1 the result reports of a successful FIA Grid Only Alternative simulation are only available to view from the CAVI, and not within FIA. 
  2. "Could Not Find Terrain: "null" Error
    1. For some forecasts that include an FIA project with a RAS HDF alternative (four separate RAS alternatives for Flood Damages Reduced) the below error occurs on compute:
    2. Open FIA, and under Inundation Data edit the data for the selected forecast
    3. Then relink the terrain (usually located in the watershed RAS folder). 
    4. Re-compute the FIA alternative from either the CAVI or FIA.
  3. Only one FIA alternative can viewed in FIA per forecast run. This is because an FIA simulation is created for each FIA alternative in the forecast run and given the name of the forecast. When two alternative exist the first simulation is overwritten by the second upon compute because the simulation names are identical. However, results for both simulations can still be viewed from the CAVI Reports buttons. 
  4. FIA sometimes has trouble displaying some map layers in map panels when viewing in the Web Coordinate System. If map layers do not appear, or are being projected to the wrong location, change the View settings to display in the Watershed Coordinate System.

  5. Additional data checks have been added since FIA 3.2 to make users aware of data gaps. A common data issue among older FIA models is missing damage function data for particular Occupancy Types. To fix the missing damage functions, a user can import and assign the default Occupancy Types to the missing ones. If receive the errors below in the compute dialog, see this discourse post to resolve.

Instructions for setting up Model Linking for a Flood Damages Reduced Compute using the Holdout - RAS HDF Inundation Configuration

HEC-FIA 3.3 introduced a new inundation configuration for FDR computes (Holdout - RAS HDF) that allow the user to link four separate RAS scenarios (as opposed to the previously allowed two scenarios). This gives the user more flexibility in FDR setup, and the ability to compute the without levee hydraulics in HEC-RAS instead of relying on the without levee estimation used in HEC-FIA.

  • The following steps assume that a new HEC-FIA Alternative that uses the Holdout - RAS HDF inundation configuration has already been created. 
  • Before continuing make sure that the other projects in the Flood Damages Reduced simulation (Metvue, HEC-HMS, HEC-ResSim, and HEC-RAS) are ready to be used in a FDR compute.  

To take advantage of this inundation configuration in CWMS 3.3.1 requires a few additional steps outlined below. These steps are currently necessary due to limitations connected with the HDF 5 output from HEC-RAS, and will be improved in future versions of CWMS.  

  1. Ensure that the four HEC-RAS scenarios have been computed in the base watershed. Floodplain Mapping in the Compute Window should be turned off since HEC-FIA will use the .hdf output files instead of the .tif files. 

  2. Within the HEC-FIA project review the Flood Damages Reduced Holdout - RAS HDF Inundation Configuration to confirm the four scenarios are associated with the correct .HDF HEC-RAS output. See example below.














  3. From the Setup Tab, add a new program order for the Flood Damages Reduced compute. CWMS 3.3.0 allows the user to define multiple Program Orders. 
    1. Models > Program Order
    2. From the Program Order Popup Window: Program > New

    3. For a FDR compute using four RAS inundations, the Program Order will need to contain 4 HEC-RAS computations as shown in the example below.



  4. Assign model Alternative keys to the new HEC-RAS alternatives and to the new HEC-FIA alternative. 
  5. Create the new Forecast Run using the new Program Order and the appropriate Metvue, HEC-HMS, HEC-ResSim alternatives, as well as the newly created HEC-RAS and HEC-FIA alternatives. 
  6. In the base watershed, complete the model linking for all the models up to HEC-FIA.
  7. Next open the model linking for the HEC-FIA alternative. As seen in the image below, select the correct RAS Alternative in the Input From column, but at this time the .hdf files will not appear in the menu under Location/Parameter. We will manually edit this in the next step. 


    1. Next select the correct model linking for the ResSim Holdout Time Series. Then click apply and and also save the overall watershed.
  8. Close the watershed, and from File Explorer navigate to watershed > "Name of Watershed" > cavi > modelLinking
    1. Open the .Linkages File associated with the FDR Forecast run in a text editor such as Notepad ++
  9. Use CTRL F to search for <ModelAlternative Program="FIA"  this is the location in the file that stores the Data Locations for the FIA Alternative. The FIA section is shown below.

  10. Confirm that the file name for the alternative is listed in the first line of the FIA section, if not add as shown in the first line of the above image: File="fia/alternatives/North_Branch_FDR.alternative"  (replace North_Branch_FDR with the name of your FIA alternative)
  11. Each of the four FIA Data Locations need to be edited to link to the .HDF files. The following is the example for the Regulated Grid:
    Before:
    <DataLocation Name="Regulated Grid" Class="hec2.model.FileDataLocation" ComputeType="Computed" LocationType="FILE" Model="RAS-Regulated_WL" Parameter="ALL" OutOfDate="false" PrevModelIndex="4">
              <ModelAlternative Name="North Branch FDR" Program="FIA" />
              <DownStreamLocation>
                <DataLocation Name="Savage R Savage R 0.100" Class="hec2.model.DataLocation" DssPath="/SAVAGE R SAVAGE R/0.100/STAGE//1HOUR/REGULATED_WL/" ComputeType="Computed" LocationType="TIME_SERIES" Parameter="Stage" OutOfDate="false" PrevModelIndex="0">
                  <ModelAlternative Name="Regulated_WL" Program="RAS" />
                </DataLocation>
              </DownStreamLocation>
              <FromFile>false</FromFile>
            </DataLocation>
    After:
    <DataLocation Name="Regulated Grid" Class="hec2.model.FileDataLocation" ComputeType="Computed" LocationType="FILE" Model="RAS-Regulated_WL" Parameter="ALL" OutOfDate="false" PrevModelIndex="4">
              <ModelAlternative Name="North Branch FDR" Program="FIA" />
              <DownStreamLocation>
                <DataLocation Name="NAB_Potomac.p04" Class="hec2.model.FileDataLocation" ComputeType="Computed" LocationType="FILE" Parameter="ALL" OutOfDate="false" PrevModelIndex="0">
                  <ModelAlternative Name="Regulated_WL" Program="RAS" />
                  <FileName>ras/NAB_Potomac.p04.hdf</FileName>
                  <FromFile>false</FromFile>
                </DataLocation>
              </DownStreamLocation>
              <FromFile>false</FromFile>
            </DataLocation>
    1. Bold items need to be updated (but not bold in the file)
    2. In the above example NAB_Potomac is the name of the RAS project, and .p04 is the plan number of the Regulated RAS simulation. Make sure to choose the plan number that corresponds to the correct simulation in the RAS project.
    3. The three remaining RAS Alternatives should be edited in the same way as the above example. The image below shows an example of the finished .Linkages file.
    4. ResSim Holdout linking does not need to be modified. 

  12. If the model linking for FIA is ever edited in the Model Linking Editor, steps 8-10 will need to be completed again.
    1. Recommend saving a backup file with the HDF model linking modifications.
  13. Save the .linkages file and re-open the watershed and open the Model Linking Editor for the Flood Damages Reduced Forecast Run. Notice that the Location/Parameter column is filed out with "NAB_Potomac.p04 - ALL" for each RAS Alternative. 



  14. Close the Model Linking Editor. The Flood Damages Reduced Forecast run is now ready to be used by creating a new forecast. The HDF model linking modified in the steps above will be extracted and used in new forecasts.