HEC-RAS Plugin

HEC-WAT includes HEC-RAS 6.5 by default, but can be adapted to use newer HEC-RAS versions including 6.6 and 6.7 beta releases.  The HEC-RAS 6.5 users manual provides additional information about the HEC-RAS software and should be consulted for any HEC-RAS specific information needed.

Known Issues For HEC-RAS Plugin

HEC-WAT simulations that use multiple HEC-RAS plans as model alternatives in the compute sequence have been known to run into data corruption issues where the HEC-RAS software associates the wrong geometry with each plan.  This issue is being tracked by the HEC-WAT, HEC-RTS, and HEC-RAS teams but a specific fix has not been identified due to the intermittent nature of this issue.  We recommend teams that are using multiple HEC-RAS plans in a single HEC-WAT simulation to back up their HEC-RAS plan and geometries files regularly outside of the HEC-WAT watershed folder, and replace these files whenever the data corruption occurs.

HEC-WAT with HEC-RAS model alternatives being run under a Distributed Compute occasionally encounter a race condition where the HEC-RAS model begins to compute before the HEC-DSS records from the previous model in the sequence have been written out to disk.  It may be appropriate to use the scripting plugin to add a script that waits a small number of seconds after the previous model in order to delay the initialization of the HEC-RAS model.

HEC-RAS FRA models that write many timeseries back to the HEC-WAT simulation DSS file may cause the HEC-DSS file to grow larger than the HEC-RAS software can read from (currently 2 gigabytes, even with DSS v7 files).  In models where this happens, please contact the HEC-WAT team about an experimental feature that copies RAS timeseries outputs to a different DSS file for reach event.  This can help prevent the input DSS file passed to HEC-RAS from growing beyond that two gigabyte limit.