Culvert entrance cells ignore mod elevation

[John Keyser K]

I have around 30 culverts in a model and 2 give me an error that the culverts are below ground elevation. I have tried a refinement region and channel modification (same method I have used on other culverts) to edit the ground elevation but it doesn’t affect the geometry when the model is run. I Remade the whole model and it gave me the same error on the same culverts. I have recreated all components involved with no luck.

Any help would be appreciated.

John

[Jonathon McDonald]

Add a surface modification polygon at the entrance to the culverts just a few hundredths or so below the inverts.

[John Keyser K]

I wasn’t clear on what I did already, this is what I have done already and tried some variations. When I set the elevation of the modification it ignores it and refers to the existing elevation. Ive tried using the different “Modifications Methods” with no effect.

[Chris Hauser]

John, have you tried this with a smaller model involving only the “problem” culverts? I wonder if there’s a bug due to the number of culverts involved (although that doesn’t seem like a large number to me).

• This reply was modified 1 year, 1 month ago by Chris Hauser.

[Jonathon McDonald]

Hmmm. I ran a model last night with a modified surface polygon applied to the terrain at culvert entry in order to fix this error with no issues. Ensure your culvert centerlines are drawn in the correct orientation based on your flow. Could your inflow and outflow elevation be reversed if your culvert centerlines have a backwards orientation?

[Eric R]

I’m not sure, but have you seen this video?

youtube.com/watch?v=fnJrZVRwCks&ab_channel=StanfordGibson

Maybe it can help.

[Luis Partida]

I would make a virtual clone of the terrain you have. Then recheck the elevations at the problem structures and I would even add a new modification on top of that modification. The next thing I would do is the basic dumb RAS debugs like save and close and reopen, disassociate that geometry with said terrain, save close reopen, rename the terrain save close and reopen, change the culvert invert to allow the model to work run it for a short duration and then go back and adjust back save close reopen…I know this isnt much help but we all know RAS is buggy as hell sometimes

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