culverts impacting watershed delineation

[ZacharyBenedetto]

Hello,

I am delineating watersheds in an area of PA for a project. However, Some highways are recognized by ArcGIS as drainage divides because they are higher in elevation, but there are actually culverts going under these highways, allowing drainage to pass through, therefore removing or moving the drainage divides. I haven't been able to acquire the locations of the culverts, so I'm not sure how to resolve the shapes of the watersheds yet. Has anybody run into this sort of issue and knows methods that I can use to go about solving this?

See below, the main highway going diagonally across the picture creates the white drainage divides over it.
[ATTACH=CONFIG]30461[/ATTACH]

Thanks!
Zachary Benedetto
B.S. Civil Engineering '14
B.A. Geology '14
Lafayette College
5165234843

[MarkBoucher]

You can "burn streams" (or culverts) in the DEM to account for water flowing under the roads.

See these threads
http://forums.arcgis.com/threads/100210-Deliniating-Drainage-Areas?p=356888&viewfull=1#post356888
http://forums.arcgis.com/threads/99125-Water-drop-trace

Also, the link under my signature may have helpful hints.

[ZacharyBenedetto]

Thanks for the quick response, Mark. This is very helpful.

Cheers,
Zack

[ZacharyBenedetto]

Also Mark,

I have ArcHydro for 10.1 which I am planning on using to re-delineate the watersheds that I originally made using Spatial Analyst. I have the ArcHydro Tools 2.0 Tutorial as I am new to ArcHydro. Will that suffice for the 10.1 version or do you know if there is a newer tutorial?

Thanks,
Zack

[MarkBoucher]

Zack,

I saw your post in the Arc Hydro Forum. I don't know if the tutorial is 100% compatible. I haven't gone through it myself.

[ZacharyBenedetto]

Okay, well as for the many various steps of tools that it says to do for preprocessing and such before being able to actually delineate the watersheds, do you always have to use all of those tools? Or are there situations where you only use some? I saw a different forum post where you put a picture up of your model builder flow chart and I don't think it included quite all the steps in the tutorial.

I was wondering if there were steps that could be skipped because my model builder keeps crashing arcmap for me when I try to use it with ArcHydro tool. If I have to reprocess the whole thing for some reason, it would be very tedious to do one tool at a time without model builder. I saw posts on your ArcHydro thread with tips on how to avoid crashing, but is there any post you know off hand that  solves problems specifically with model builder crashing from ArcHydro tools?


Thanks,
Zack

[MarkBoucher]

The only tips I can think of are:

• perform the processes with the data on your local drive.


• put the agreestream and innerwalls layers in a geodatabase


• make sure the file and folder names are not too long and make sure they have no spaces.

Other than these suggestions, I don't have other big ideas. A while back the model builder model would crash during/after the stream definition or stream segmentation step. However, I found out that when I refreshed them in the catalog the str and/or strlnk layers were fine and I could move on from there without starting over. I believe moving the projects to the local drive took care of these errors.

[ZacharyBenedetto]

Great, thanks for the tips!

Zack