[ckatsoulas]

I would try this by modelling the aqueduct as a culvert. you could calculate the capacity of the aqueduct and then use an equivalent culvert size or the outlet rating curve. the overflows would then be directed to the creek below.

[ckatsoulas]

If you have created shape files, you can simply drag them into RAS mapper straight from the Explorer window(they end up in “Map Layers”). Or you can right click on map layers and use import function from sub-menus.

[ckatsoulas]

after you create a cross section in the geometry window you go into the “steady flow data” window to set your flow and then click the “Reach boundary conditions” box. The box that appears gives you an option to set and upstream and downstream boundary condition such as a known water surface (this is what you want), critical depth, normal depth or a rating curve.

[ckatsoulas]

The only time I got this type of error code is when I used the variable time step option and my starting time step was too high. Try using the fixed time step or change starting time step with a low time interval.

[ckatsoulas]

haha…well it is Gods Country after all…in fact, the bible measurements of the new Jerusalem is almost the size of Australia…go figure…!!!!

As for XP-SWMM it is great but being the aussies we are, everyone here favours TUFLOW with no GUI…

[ckatsoulas]

Luis I wouldn’t mind seeing the new hydrographs you entered and also the options you set. I also tend to set courant to 0.5min and 1.0max as a default

[ckatsoulas]

I guess a temporary quick fix to this would be to put the latest post on top.

[ckatsoulas]

Luis, you say you have said before stage hydrographs don’t work, can you elaborate on what is wrong with this in HECRAS. I don’t see an issue in this run with the stage hydrograph.

[ckatsoulas]

Lonnie can you please explain in more detail what you mean about the “maximum courant being less than the minimum value” and what you did to fix it.

[ckatsoulas]

Guys thank you so much for taking the time to look at this in depth, I really appreciate it. The reason for the 5.6m tailwater is that I am trying to reproduce the water level (5.7m) at the subject site from a flood study prepared by another major consultant for the greater flood area. With normal depth the flood level drops to RL 5.4 at the subject site. I had to use a triangular hydrograph as I was not given a hydrograph just a flow. I guess I will have to wait and see what HEC say about this but at least it will help them fix any bugs for the rest of us.

[ckatsoulas]

Luis, creating the alignment is not an issue its then trying to drop a box channel to line up from the centre of the channel to the centre of the river alignment. when you create different width cross sections it’s not easy to tell where the river alignment sits within the cross section.

[ckatsoulas]

Luis you can download the model from the link below to get a better idea. I have sent it to HEC also but no reply yet

https://www.dropbox.com/sh/84rttr0zsku7pk6/AAAC1M8RVlvlKcRzxTY6h_CZa?dl=0

thanks for looking into this

[ckatsoulas]

No, no warm up initiated. I even checked the culvert property box in case there was anything that would introduce flows but nothing. It really has me stumped. I may have to give the model to HEC for checking.

[ckatsoulas]

Thanks for reply Luis, the cords were entered by using the control key so they are correct. The long red lines you see are just breaklines for the channel. I had setup some initial conditions for tailwater that I later deleted but this is still happening. I’m thinking there could be a bug with the initial condition not being fully removed?

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