Dam Break but Water Level Doesn’t Drop

[Anonymous]

I’ve created a HEC project to simulate a dam breach, and it’s currently running with no errors. However…

I have an inflow hydrograph flowing into the most upstream XS that has a flow rate of 0.5 cfs. As far as I can tell I have no other inflows whatsoever. I also set the pond elevation at 994.75 (set this condition via the XS directly up from the dam). However, once the dam breaches one hour into the model, the water elevation at the breach never drops–the pond keeps refilling. There’s definitely something going on with the DS stations immediately after the dam as their XS profiles are flattened quite a bit (due to exaggerated EG… what does that stand for, anyway?).

I’ve uploaded the project directory (in a zip file) to the DropBox link below. There should be just one prj file (I think Brackett’sCreek2.prj). I have also included a screen shot of the main screen showing the Project, Plan, Geometry and Unsteady flow files to make sure the right ones are selected. Also, I set my time step at 6 seconds.

https://www.dropbox.com/sh/ayv07lcccyyfiue/AABVEctObx4-ZnqdLz8zWfAka?dl=0

Any input would be greatly appreciated!!!

[Anonymous]

I’ve been applying every “solution” I find on the web trying to fix the problem but to no avail. I’ve gone through PPT presentations on common errors and how to fix/avoid them, I even used the troubleshooter on this site, etc., etc.

Browsing through the information in HEC RAS, in the standard profile output table I have EG Elev’s in the hundreds of millions and EG Slopes in the billions and tens of billions. Something is obviously very, very wrong here… I feel like I’m doing nothing but sitting here spinning my wheels.

There are a few other things I can do (clean up my XS’s a bit since they were extrapolated from lidar in Civil 3D), etc., but again, it seems like there must be something very obvious that I must be overlooking.

[Anonymous]

The quickest way to assemble your RAS files for other folks to look at is to go the main RAS menu > File > Debug Report. This will gather all of the files associated with the current plan and make a zip file of them.
Michael

[Anonymous]

Thanks, Michael! Let me do that and upload it to the same directory in Dropbox.

Done… MUCH smaller file, and it’s called “DeBugFile.zip”

[Anonymous]

I wanted to write and give a *huge* thank you to Chris for resolving my model’s numerous issues. I have spent the day trying one thing after another, and in the end it was a little of every “typical” problem with HECRAS models. The problem was knowing what issue was happening where. Not only did he fix the model, but he explained why he did each thing that he did along with a link to one of his blogs and/or an image of each problem.

I simply cannot say enough about how professional, kind and courteous Chris was, and his level of expertise on the matter is obviously significant. Thank you, Chris!

[Chris G.]

Thanks for the shout-out Jonathan!

[Author]

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