A summary of major bugs that were found in HEC-RAS Version 6.1 and fixed for Version 6.2 (Released 11 March 2022) is provided below.


Major Issues

Adaptive Time Stepping Courant Number

HEC-RAS has two methods for computing the maximum Courant number used for the adaptive time stepping. One is based on the face velocities while the other is based on the cell outflows and volume (i.e. residence time). The default method is the face velocity method, but in 6.1 there was a bug in which the residence time method is always used no matter what method is selected by the user. 

Inundation map area

Inundation area was incorrectly calculated for multipart polygons. 

Culverts in SA/2D Connections

If the Depth Blocked setting for culverts is left empty, the culvert may crash or be completely blocked.

Box Culvert Chart #8 Scale #1

One of the inlet coefficients ('submerged Y') for a box culvert for flared wingwalls (chart #8) flared 30 to 75 degrees (scale #1) was using 0.86 when it should have been using 0.81 according to HDS No. 5. 

2D Unsteady Stage Boundary Condition

The stage boundary condition for 2D areas can produce instability problems when the user-specified water level is below the boundary face invert elevations. 

2D SWE-EM Solver Face Area Bug

The Shallow Water Equation Solver with the explicit Eulerian advection scheme (SWE-EM) had a bug in which the values for the face areas were incorrect. This produced only slightly different results.

2D Implicit Weighting Factor

The 2D Implicit Weighting Factor is not being set correctly for the warmup or simulation and is defaulting to the value 1.0. Therefore, this is only an issue if the user enters a value less than the default value of 1.0.

Multi-River Riprap 

The River-Reach-RS drop down does not repopulate the correct reaches if a new River is selected

2D Sediment Subcell Elevation Plotting Error in SI Units

The sediment subcell bed elevation plot does not produce correct subcell areas when running in SI units. Spatial maps of bed elevations are correct in both SI and US English unit systems. Only the subcell bed elevation plots are affected.

2D Sediment Consolidation with Morphologic Acceleration

The morphologic acceleration was not being considered in the calculation of consolidation. Therefore, Morphologic Acceleration Factor values other than 1.0 do not yield correct results.

1D Bridges being assigned wrong River after saving in RAS Mapper

If the model contains river reaches with the same name, For example: River A, Reach A; and River B, Reach A, a 1D bridge may be assigned the wrong river after saving in RAS Mapper. 

Unhandled Exception Saving Geometry in RAS Mapper

If the model contains interpolated cross sections and 1D bridges, then there is a chance an unhandled exception will occur in RAS Mapper on save. 

Precipitation Ratio Not Being Applied

The optional precipitation ratio specified in the Unsteady Flow Data editor is not being applied.

Boundary Condition Line Incorrectly Assigning Storage Area/2D Area. 

Sometimes adding a boundary condition line using RAS Mapper will assign the wrong Storage Area or the wrong 2D area.  The ability to reassign with a right click menu was added for version 6.2.

Riprap Calculator Lagged XS update

If you change the Reference XS in the riprap calculator it does not update the hydraulics until something else in the editor is changed. 

Sanitize Infiltration Classification Names CrashAttempting to sanitize an infiltration layer will cause RAS Mapper to crash. 
Computing Face Profiles Slow With Polygon Mods With Control Points

Some users are reporting longer than usual times for computing face profiles when their terrain has polygon modifications with control points. 

Sediment Routing Method Connected to the Classic Output SelectionIf you select the "Limit to Water Velocity" method in 1D sediment routing it will only work if you also have the "Classic Output" file selected.  The Classic Output is large and redundant with information in the sediment HDF 5 file. 
Quasi-Unsteady Uniform Lateral Inflow Across StructuresHEC-RAS does not compute the reach lengths correctly to weight the uniform lateral flows in Quasi-Unsteady if there is a structure in the sub-reach.  It can compute an inflow that does not sum to the user specified inflow over all cross sections.  And if there is a sediment rating curve attached, it does not always bring in the expected sediment (since sediment load is function of flow).  This was fixed for 6.2.
Flow Optimization table not showingThe Flow Optimization table is not showing the proper information for the selected structure type.  Junctions are always on top.
2D Sediment Computation MultiplierThe sediment computation multiplier does not work for 2D sediment.
Default line styles not applying/saving in Hydrograph plot.Changing the default line styles in the "Lines and Symbols Editor" by right clicking a plot will not change associated lines to that style, and changes will not be saved. 
Datasets containing gates will cause the Hydrograph plot to crash if more than one plan is selected.Trying to open 2 plans at once for a dataset with gates will cause the plotter to crash.

Datasets containing gates will sometimes not plot in Hydrograph Plot

After an unsteady run, and trying to open the hydrograph plotter, the hydrograph plotter may show an error box "Sequence has no elements." 

RipRap calculator not loading with unsteady datasets

The riprap calculator will not launch when a project with a project with unsteady data is loaded.

3D Viewer not launching from main RAS window

The 3D Viewer will no longer launch from HEC-RAS main window.  Can launch 3D Viewer from RAS Mapper. Details on launching the 3D Viewer are here.

Minor Issues

Groundwater interactions plot in the Hydrograph plotter.
Fixed being able to edit feature attributes if the column is greyed out.
Fixed structures with gates not plotting total gate flow in the hydrograph plotter.
Fixed structures with culverts not plotting total culvert flow in the hydrograph plotter.
Fixed incorrect polygon area calculation for multipart polygons.
Hydrograph plotter time series max table should include the plan name if multiple plans are selected.
Fixed unhandled exception from trying to add group layers as a watch.
Max and min buttons should disable for steady result maps.
Fixed being unable to change column for vector SSURGO datasets when adding soils data.
GSSURGO gdb files that are not compatible with RAS should provide a better error message now.
Fixed 3D Viewer holding on to out-of-date pre-process files, old files should delete automatically now.
Fixed a crash when trying to create a GeoTiff file from the cross section layer when a cross section did not have a profile.
Fixed not being able to create a terrain when the project has no projection.
Fixed RAS Mapper options not indicating the correct option on start.
Fixed setting surface fill making duplicate values.
Fixed modification group for terrain not appearing if a pier terrain modification layer was selected to be added.
Fixed pier terrain modifications disappearing after saving the layer if the pier was saved at a negative coordinate.
Fixed rare instance where trying to import control points into a multi point polygon terrain modification layer would cause a crash.
Polygon layers should be able to export to a raster file now.
Fixed polygon and line terrain modifications disappearing in RAS Mapper tree after finished editing if they had control points.
Fixed selected features getting cleared after panning in RAS Mapper.
Fixed edit points dialog crashes.
Fixed a crash in the shape file features import dialog that occurs when the dialog is shown in a new, empty project.
Flow hydrograph along profile lines should now compute properly for 2D Sediment.
Fixed pier terrain modifications sometimes corrupting virtual terrains.
Fixed Velocity against Terrain plot in RAS Mapper showing velocities under dry areas.
Re-added horizontal scroll bar to RAS Mapper plot tables.
Fixed the DSS Viewer not showing any rows when one of the input files has 0 rows.
Fixed Profile Lines layer not remembering checked state between RAS Mapper sessions.
Improved boundary condition line face search within a 2D area, which prevents a model run-time error message.
Fixed stored maps reverting to first time step when "Floodplain Mapping" option is checked in the unsteady compute window, and RAS Mapper is kept open.
Fixed variable label not applying to the respective line in Lines and Symbols editor.
Fixed View Points option for Multipoint layers always showing the first feature.
Fixed slow loading of multipoint, polyline, or polygon shape file where the shape file projection is different from the project projection
Fixed inundation boundary maps ignoring terrain modifications when being generated.
Fixed Rating Curve plot showing No Data to Plot for internal SA/2D connections.
Fixed being unable to save a geometry if it contained interpolated cross-sections as well as 1D bridges. Fixed 1D bridges getting the wrong US river name if there were reaches with the same name on multiple rivers.
2D Sediment variables profile plot will now work with multiple plans.
Can copy paste symboligies from RASMapper to the 3D Viewer now.
Fixed some 2D bridges not plotting in RAS Mapper under Plot SA/2D Conn Data
Z-Scale option in 3D Viewer can accept a user-typed value.
Fixed Flap Gates option for SA/2D Connections being reset after saving geometry in RAS Mapper
Fixed not being able to import .img files when creating a new landcover dataset.
Groundline modifications should be more forgiving with polylines that have consecutive duplicate points.
Fixed meteorological station points not plotting in RAS Mapper.
Fixed zoom level being lost when replotting in RAS Mapper.
Fixed a RAS Mapper crash that results from a structure having an invalid upstream cross-section.
Fixed Manning's N calibration regions not producing correct manning's n values in 2D Hydraulic property tables after editing regions in a single session.
Fixed boundary condition lines not choosing the appropriate 2D area or storage area.
Sanitizing classification names for infiltration should work properly now.
Significantly increased speed of computing face profiles of geometries that reference a terrain with polygon modifications containing control points.
Fixed variables in the new HEC-RAS plotters being unaffected by changes in the default line style's list under "Lines and Symbols Editor" accessed by right clicking any plot.
Fixed the Hydrograph plotter variables list having duplicates if more than one plan is selected
The editor that pops up for structures in RAS Mapper should no longer allow /'s and \'s.
Fixed SA/2D Connection hydrograph plot not loading.
Fixed an issue that prevented the Hydrograph Plotter from showing if the Geometry had inline structures.
Fixed Ratio option not applying to precipitation/meteorology values in results and event condition layers.