US Army Corps of Engineers
Hydrologic Engineering Center

Skip Navigation LinksHome > software > hec-ras > known issues


This page will be updated as important issues arise.

Known Issues in HEC-RAS 5.0.7:
  1. Lateral Structure with Bridges Connected to 2D Flow Area. If a user connects a Lateral structure from a 1D river to a 2D flow area, and is using the "Normal 2D equations" for the flow transfer, and if there are bridges that are crossed by the Lateral Structure, the software has a bug in that it is allowing water to leave the 2D area across the lateral structure in the bridge computational zone (Between the two cross sections that bound the bridge). No flow is supposed to go in or out of this region, due to the fact that the 1D bridge/culvert solution cannot change the flow in the middle of the bridge/culvert.

  2. Bug in Using a Rating Curve for a Gate Opening. If you use a rating curve for a gate, and you only put in two values, such as 0.0 and max gate opening. Then you use time series of gate openings and put the gate at the max opening the entire time. Program is not using max gate opening, instead if water surface is below top of gate it is using max water surface to go into the curve with that as gate opening. This is not correct. And gives the wrong answer if the gate is out of the water and the flow through the gate should be weir flow and not gate flow. If you have a situation where the gate will go above the water surface elevation, do not use this rating curve option, it is not working correctly. Go back to using the normal gate equations instead of the rating curve.

  3. Array Dimensioning mistake for gate groups with spatial coordinates. If a structure has more than one gate group with spatial coordinates for the gates, the program is failing to dimension the arrays correctly to hold this spatial data. Generally the program will crash when it tries to execute, with an array bounds error.

  4. Volume accounting Display Error. A bug was fixed in the volume accounting output for version 5.0.6, but this inadvertently caused a bug in the volume accounting for version 5.0.7. If a user has a model with 2D flow areas and one or more storage areas, but no 1D reaches, the volume accounting fails to account for the final volume left in the storage areas. It shows it as blank and interprets it as zero. This then looks like there is a large volume error that actually does not exist.

  5. Error with using Rules when structure is connected to 2D flow Area. There is a bug in 5.0.7 when Rules are used to control gates in an SA/2D Hydraulic Connection that is connected to a 2D Flow Area. Rules for a SA/2D Hydraulic Connection will work if it is connected to 1D storage areas on both sides. If either, or both, sides are connected to a 2D flow area, the rules will not work. There is not a work around for this.

  6. Simplified Breaching: There is a bug in the Simplified Physical Breaching Routine for “Overtopping” breaching only. Right before the 5.07 release of HEC-RAS was made, the Simplified physical breaching data editor was modified, and one of the necessary data entry fields was deleted. If the user picks an over topping breach, the additional required field is for the user to enter a starting notch width for evaluating the velocity going over the structure. Since the user cannot enter this field, the breach never starts.

    Work Around: Change the breach type from Overtopping to Piping Failure. Set the initial elevation to near the top of the structure (ex. 1 foot below top of the levee). This will then allow the breach to start to form near the top of the structure, similar to an overtopping failure.