[Chris Hauser]

Erica-

To what flow depths are you trying to calibrate these very low flows? What are your typical cross-section dimensions and spacing? How accurate are you trying to get?

Without knowing a bit more, it seems to me that you may be asking HEC-RAS to do a bit too much in this situation.

[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.

[Chris Hauser]

Luis-

I had thought that doing that would require making the Reservoir a “separate” flow area mesh, but perhaps I was mistaken about that. I will give that a try.

Thanks!

[Chris Hauser]

Thanks Luis. I have tried that before, in which I create a Storage Area, then I create two “C-shaped” 2D flow areas that together completely surround the storage area. The two flow areas also meet each other at the top and bottom ends of the “C”s.

It does get a bit tricky sometimes to get the two connections between the flow areas at the ends of the “C”s to work properly, unless there happens to be a convenient “ridge” like a roadway berm to act as the “border” connecting the two flow areas. Thus, why I wanted to know how others have approached this problem of laying out an upground reservoir in a flat area.

[Chris Hauser]

Well, I just found the new web site and forum. I have to admit I’m bummed out about the old posts disappearing, but I’m glad that at least there’s a new one to share information. (I just found a fix for a bug I encountered, so thanks Chris for running this site!)

[Chris Hauser]

I am having this problem in a model I “picked up” form others. The model already had some cross sections with multiple obstructions.

I needed to add a second obstruction to a particular cross-section that already had an obstruction. The original obstruction was previously input using the “Multiple Blocks” radio button, so there was no issue there. (My new obstruction was in the right overbank, near the original obstruction.)

When I tried to add the second obstruction, I got the error message you guys described. I did not save the geometry file at this point, but simply exited the program without saving anything.

I re-opened the project and selected the plan in question, then opened the geometry file, which was in its original state with only the one original obstruction at my cross section. I deleted the obstruction and saved the file, then exited the program.

I then re-opened the project/plan/geometry file, which now had no obstruction at my cross section. I then added both obstructions (the original and my new one) using the Multiple Blocks option, and it worked! I saved my file and ran my model successfully.

Just thought I would verify for everyone that this fix does work. I’d still like to see this bug squashed in the next release…

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