Upgrading your HEC-RAS Model in CWMS

The best practice for upgrading your HEC-RAS model in CWMS is to ensure your RAS alternatives run in base.

Ensure your base model has all the data available to run contained within the watershed: input DSS data, terrain, projection, land use etc. A good place to store this data is in a "Data" directory created in the "ras" directory. Once that data is there, ensure your RAS project is setup to utilize it.

Missing Observed Data

If observed data was setup in your HEC-RAS Unsteady Flow Editor so that it can be viewed in forecasts, those links will likely be broken upon updating to the latest HEC-RAS. Fortunately this is an easy fix.

Copy an example forecast.dss file that contains the observed data into the watershed's base directory.
Edit observed data for the base HEC-RAS model. In the HEC-RAS unsteady Flow editor and use the example forecast.dss as the source file.

HEC-RAS now stores this as a relative path so when forecasts are created the source DSS file is the proper forecast.dss file.

Restart files for initial conditions must be generated from the latest version

Known Issues:

Error Creating Boundary Condition File

This issue impacts RAS models in CAVI with stage boundary conditions at cross-sections when upgrading from 5.0.7 to 6.1. To workaround, refresh the first Stage Hydrograph boundary condition in the RAS model, then refresh the model linking in CAVI.

Refresh the first Stage Hydrograph BC:
- In the base model's Unsteady Flow Data Editor, find the first occurrence of a Stage Hydrograph boundary condition
- Toggle the boundary condition to use the table instead of DSS and enter data spanning the simulation
- Run the base model. Don't have to wait for a full compute just need the unsteady flow simulation to start.
- Toggle that boundary condition back to DSS and compute again.

Refresh the CAVI model linking:
- Open the CAVI Model Linking Editor for the RAS plan in base and toggle a location so CAVI recognizes a change.
- Toggle back, and hit Apply to write out the linking file.

Steady Flow Forecast Creation Issue:

When creating a forecast with a steady flow plan, no forecast RAS project (.prj file) will be created for the forecast model.

To resolve this, in the base RAS model turn OFF the "Get Peak Flows at all Locations for Final Profile"

This option can be turned back on in the forecast, and the user can run the "Import Data" button to get the peak flows.

If a standalone RAS model is open and a users launches CAVI and opens a watershed, the standalone model will close.

This has been a long standing issue that has been very difficult to resolve.

Using the Action Buttons in a CAVI forecast to access HEC-RAS editors (Plan Data, Geometry Data, etc.) can cause issues when there are multiple HEC-RAS plans in a forecast.

When using the Action Buttons to switch back and forth between multiple RAS plans the geometry files are getting overwritten. To avoid this, only access RAS geometry editors by launching the RAS plugin.

Hidden prompt may appear when using CWMS "Save Watershed As" feature.

There is a prompt that is caused from a missing file that was introduced in new RAS versions (so this should only impact models that were developed in 5.0.7 or older). A prompt will display saying that *.u*.hdf is not found. This prompt has a chance of being displayed in the background. So if you notice the save as is stuck on RAS, make sure to look for this dialog (the copy will not progress till this dialog is cleared).

HEC-RAS Know Issues Page:

The list of know issues and status for the latest standalone version of HEC-RAS is here: https://www.hec.usace.army.mil/confluence/rasdocs/raski/latest