| Product(s): | Bentley SewerGEMS, CivilStorm, StormCAD |
| Version(s): | V8i, Connect Edition |
| Area: | Layout and Data Input |
Why does my calculation fail with a red user notification when using the Irregular option for the Gutter Shape of a catch basin?
"irregular gutter is not a valid selection for this solver. Please select different gutter shape."
"Gutter Shape is invalid. Perhaps the Catalog Gutter reference is not set or it no longer exists."
"Irregular-shaped gutter is a valid option for a gutter link, but it is not valid for the inlet capture calculations at a Catch Basin. Please select a different gutter shape on the Catch Basin."
The Irregular gutter shape is supported for the gutter link element, but not for the catch basin (gutter at the inlet location). It is not part of the HEC-22 standard that the software uses for inlet calculations and there are some other technical reasons behind why this currently isn't supported. As a workaround in SewerGEMS or CivilStorm, set the shape to something else at the catch basin and keep it set to Irregular in the gutter link element itself. Then, look at the gutter link to check for depth/spread at the next downstream inlet.
Note however that the Bentley StormCAD product currently does not support the Irregular option in the gutter link either. There are some cases where the user is allowed to configure a gutter as irregular and attempt to compute, in which case a red user notification will be presented and the calculation will fail. One example would be if the model was created in CivilStorm or SewerGEMS and opened in StormCAD, or if the numerical solver in CivilStorm or SewerGEMS was changed to GVF Rational. In these cases, one of the HEC-22 supported gutter shapes must be used.
Also, consider that all Gutter sections need to be User Defined and not from a Catalog. A user reported that the delivered drainage nodes that he looked at had gutters defined as from catalog and this resulted in errors.