Junctions not appearing in HEC-RAS after creation in HEC-GeoRas

[FraserMorgan]

When I export RAS files from ArcMap 10 to HECRAS and I do not see junctions in the Hec RAS geometric data editor, even though the attribute table for the stream line shows the correct to and from nodes. However the ToSta and FromSta columns appear to be listed incorrectly (ToSta is just the length of the reach and FromSta is always 0)

Based on another answer on a similar aspect on this forum, I have completely double checked that the river junctions are in the correct direction and are correctly snapped (I used 'end' sapping tool used rather than 'vertex' snapping if this makes any difference).

I also tried using the 'move object' tool in the Hec RAS geometric editor to overlap tributaries, however no junction appears in the geomery viewer or propagated into the steady flow boundary conditions editor.

Does anyone have any suggestions as to why this is the case and/or how we can create junctions that are recognized by HEC-RAS?

Appreciate any help anyone can provide.

Fraser

[MattMead]

You wouldn't happen to be working with only 2 stream reaches would you?  If that is the case RAS requires three streams to make a junction.  Some of what you wrote(Snap to end, move object didnt work) makes it sound like you have two streams that come together end to end and you want to make one long reach with distinct names/river stations.  If that is indeed what you want to do you need to make a dummy reach and use that to make the junction. 

If you are trying to combine three streams, try making three separate lines in the River file if you havent done that already.  Failing that though, I am at a loss.  Move object should always split the reach as long as there are cross sections on either side of the junction.

[FraserMorgan]

The catchment we are working with is quite large (The Ba River in Fiji) and has a number of tributaries (see the attached screenshot 'Ba Catchment full'). I have zoomed into one of the junctions and taken three separate screenshots showing the attributes of each of the three tributaries. The two upper tributaries ('Ba Junction Upper East' and 'Ba Junction Upper West') both show ToNode=5 and the lower reach ('Ba Junction Lower') shows FromNode=5 so it seems to have correctly identified the junction node. The 'Ba Junction Vertex Snapping' screenshot shows the vertex of the river layer line snapping to the junction using the vertex snapping feature (this was done throughout the catchment). The 'Ba River Attribute Table' screenshot shows the unpopulated FromStation field. We have tried deleting the other fields and recreating everything using the Stream Centreline Attributes tool in the RAS Geometry menu, but it hasn't helped.
The HecRAS full catchment screenshot shows the geometric data editor for the full catchment if that provides any clues. The 'HecRAS Junction Overlap' screenshot shows the overlap we created by using the 'Move Object' tool in geometric data editor. Finally the 'HecRAS Steady Flow Editor' screenshot shows the Steady Flow Boundary Conditions window. We populated the downstream values using a normal depth of 0.001 as a very rough approximation, but it doesn't resolve the problem of the lack of junctions.
Are you able to suggest where we may be going wrong?

[FraserMorgan]

Additional screenshots as referenced in previous post

[MattMead]

Wow, yeah definitely not the 2 streams only issue 🙂

As a quick test in another copy of your RAS model create a river reach by just drawing it in and then use move object to try and create a junction on one of your GeoRAS imported streams.  If that fails you at least narrow it down to a RAS issue and not GeoRAS. 

If that works though, the only thing I could think to try next would be to export your data into another georas setup a couple stream reaches at a time.  Once everything is broken out into separate import files you can import them into RAS and see if everything junctions correctly and build it up from there.

Good luck!

[MichaelSherwood]

This is late, but I was using this thread as reference, so I figured I would share. My junctions weren't showing up and I realized the tributaries in my stream network weren't connected by a few feet when I zoomed in. I "Extended lines" and then "Split lines (stream network) by points (junction nodes I created in Arc)" and all my junctions came in. "Repairing geometry" has helped me with other weird geometric issues when bring in from ArcMap.