[Lonnie A]

Use lateral weirs to model the levee not the levee function in the XS editor. You’ll need to have the “flow optimization” under the steady flow window options selected.

[Lonnie A]

I would still include ineffective in the left overbank. But would apply it along something like the redline is showing. I don’t have a equation for how I came up with it. I’m just visualizing how flow would exit the crossing and then need to navigate around the hill in the left overbank with consideration of how the channel alignment is.

[Lonnie A]

It may be the way the sections are oriented. From what I visualize in your description the cross-section overbank should be running up the roadway embankment on one side of the channel where the embankment parallels channel. (excuse the crude pictures)

Like this

Not this

[Lonnie A]

I found out recently that you can view boundary condition hydrographs in the DSS file (at least in the March version you can). If your downstream is set up with normal depth boundary you should be able to compare the hydrographs and if grid set up properly with cells aligned like you would have XS the cell WSE along the boundary should all be very similar so you can select one cell in rasmapper to view the time series.

[Lonnie A]

If understand correctly it’s the deck elevation that has too many points. What I would do is create a “junk” geometry file and copy/paste the deck points into a made up cross section. Then use the auto point filtering tools on it….then copy those results back into your bridge editor.

[Lonnie A]

If the flowline of the first section on the tributary is higher than the initial conditions depth of the receiving channel that will usually cause stability issues. In my models where there is a significant elevation difference across a junction I will put in a inline weir at the downstream end of the trib.

I basically copy the last section I’ve cut from the surface say 5′ downstream. Then place a inline weir between the two sections. The inline weir geometry is the same as the bounding upstream section. The downstream section flowline is adjusted to match up with the receiving channel.

[Lonnie A]

Marulke,
I understand now what you were referring to. I looked at one of my older models I had available and also see differences between the DSS results and the table results. There were differences in both V4.1 and V5.0.
Sorry I don’t have an answer as to why they are different. I’ll try and look into it some and if I find anything I’ll be sure to post back.
Lonnie

[Lonnie A]

The storage area flow hydrographs are net inflow and won’t match the storage area connector. The net inflow is the flow from the storage area connector + any flow assigned directly to the storage area minus flow leaving the storage area.

[Lonnie A]

I would put a inline weir with gate at the upstream face of the culvert. You’ll need a xs between the weir and culvert.

[Lonnie A]

I don’t believe you can directly. But if you set the detailed output interval to the time steps you want you can use the inline structure table and add weir flow area to it. Then in excel simply divide Q weir by the weir flow area.

[Lonnie A]

If I understand your question correctly yes you should be able to model one side of the channel in 2D. You can trim the left overbank to near the channel. Place a lateral weir at the end of the trimmed left overbank and use the 2d area for the left overbank floodplain. You can use several laterals so that flow can go from/to different reaches.

[Lonnie A]

To connect your storage area you have to move the point at the end of the reach to be inside of the storage area. Use the edit pull down within the geometry editor. It may already display like it is inside but when you do the move it will ask to attach it and then snap to the boundary. Similiarly if you move the end of one of the reaches to the reach you are trying to attach to it’ll ask to create a junction.

[Lonnie A]

Plot the hydrograph for this section and compare it to the adjacent sections. The output table is showing results for Max WS which won’t neccissarily occur at Max Q. There may be some stablitity issue and you had a spike occur at this section which is why max ws occured at a low flow.

[Lonnie A]

You may need to add ineffective flow in the right overbank to keep the continuity of the flows. The conveyance capacity in the overbank increased between profiles and took some additional flow out of the channel. It really doesn’t look that bad magnitude wise. I wouldn’t consider 380 to 190 cfs of flow in the channel out of almost 3000cfs drastic. If it were going from 1000cfs to 190cfs then yes.
If you already have ineffective flow in overbank and it is overtopped this will cause this…the same if levee point overtopped. Playing around with effective flow station/elevation will fix it but in this case I doubt you’ll see a much if any difference is WSE.

[Lonnie A]

Your lateral weir elevations have to be equal or higher than the lowest point on the cell face. I know for sure in the October version it will tell you where the weir elevation and face elevations have a problem after you try to run it. You just have to go through your lateral weir and raise elevations at those locations. This is often between the weir stations. So if you have a wide spacing of points on the weir you might need to add intermediate points. Otherwise raise one or both bounding points.
I’m hoping they eventually make an option for the lateral weir to take it’s elevation from the cell faces. If you have a detailed grid that is generating a lot of points for the lateral it’ll help some if you filter the points in the weir. What I often do is make a dummy cross section and paste the lateral weir GR points into it then use the xs point filter tools to trim it down. This gives you the ability to see before and after so you can see what the filter is changing.

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