HEC-RAS Known Issues

Description

Status

The length of the time step inside of the DLB code is set at the start of the breach and it is not checked again. This is a bug if the length of the time step is changed during the breach as can happen if the user uses adaptive time step or adjust time step based on a series of time divisors.  Workaround: Use a constant time step for the whole model or during the breaching period.

RESOLVED

2D Bridge Scour export used approach-section WSE for the contracted section. Updated export to use the WSE at the contraction reference line. This primarily affects the computed/represented elevation of the abutment scour hole in Hydraulic Toolbox.  Workaround: If you are doing abutment scour you can manually replace the Define WSE prior to Bridge.

IN PROGRESS

If you build a 2D Bridge Scour file with the RASMapper tool and export it to the Federal Highway hydraulic toolbox, it imports into the toolbox as US Customary.   Workaround: The toolbox file stores all data in US Customary so RAS will have to convert everything from SI to US Cust to support SI.  Until then the tool only supports US Customary.

IN PROGRESS

If your model has multiple dam or levee breaches and some but not all of them use DLBreach, the model will crash.

RESOLVED

In the 2D Bridge Scour editor for abutment scour condition A, the tool recommends the overbank contraction reference line and the automatic import button identifies the contraction overbank reference line from the reference lines assigned in contraction scour.  This should be the Contraction Channel reference line because Scour Condition A assumes that the channel migrates into the abutment.    Workaround: In 7.0.1 just select the Contraction Channel reference line for the Contr Ref Line if you select scour condition A.  Don't use the automatic import button for this condition.

RESOLVED

"Line" type modifications will sometimes not apply the correct profile when cutting a profile from a profile line or cutting a profile for face property tables.  This can happen when the "System Name" column is used.   It is inconsistent on when there is a problem and when there is not a problem.  Workaround: We recommend you do not use system names in your line modifications for now.

RESOLVED

In DLBreach the soil internal friction input is labeled as an angle in degrees.  However, DLBreach uses the internal friction coefficient, which is the tangent of the friction angle.  The label is updated to "Internal Friction Coefficient" in version 7.0.2.  Workaround: Input the tangent of the friction angle into this input.

RESOLVED

In DLBreach grain size is labeled as mm, but passed to the DLBreach code as m.  We will convert this to mm in future versions. Workaround: Input DLBreach grain sizes as meters.  You will have to convert this back to mm in future versions (unlike the friction angle which will use the new coefficient in future versions).

Culvert flow for 2D hydraulic structures is not being computed for structures that meet all of the following conditions: (1) the 2D Domain equation is selected, (2) the Energy Grade Line is selected for the Headwater Reference on the Weir editor, and (3) the culvert is not georeferenced.  Workaround: georeference the culvert or select the Weir Equation for the overflow computation method.

IN PROGRESS

If a 2D area has "Composite Classification Valeus in Cells" turned on, and table data is changed for calibration regions, then HEC-RAS will fail to recompute property tables.  Workaround: Manually recompute property tables in RAS Mapper by right clicking the 2D Flow Areas layer and selecting "Compute 2D Flow Areas Hydraulic Tables"

RESOLVED

The "affected" faces shown in RAS Mapper for external boundary condition lines are inaccurate, it is only a visual bug, and does not represent actual "affected" faces.  Workaround: Use the geometry schematic to see true "affected" faces

RESOLVED

1D Velocity Distribution Plot for Unsteady Flow models is not displaying the correct number of slices for Bridge plots.  One velocity for the channel and each overbank is shown.  The plot was corrected for Cross Sections in version 7.0.1.

IN PROGRESS

When a dataset contains a sluice gate in a Pipe Network and a gate on an SA/2D Connection or Lateral Structure a Fortran access violation can occur, preventing the model from running. Workaround: Change the ordering of the gate boundary conditions in the .u## file so that the Pipe Network gate entries come before the other gate entries as described here: Reorder Gates in Unsteady Flow File

IN PROGRESS

In metric models, Pipe Network Side Inlet dimensions and weir coefficients are interpreted as English units in the compute engine. The impact of this is that when side inlets are entered in metric, the user will see far less inflows than expected. 

RESOLVED

In metric models, Pipe Network Top Inlet weir coefficients are interpreted as English units in the compute engine. Note, the other parameters for Top Inlets were being converted correctly. 

RESOLVED

When the 2D Area Option to Composite Classification Values in Cells is on, the geometry preprocessor was crashing while creating the 2D property tables. Workaround: Turn Composite Classification Values off. 

RESOLVED